CMC Paper: Indian Nuclear Test, Appendices

Investigating the Allegations of Indian Nuclear Test Preparations in the Rajasthan Desert

A CTB Verification Exercise Using Commercial Satellite Imagery

July 1996

Vipin Gupta and Frank Pabian

From the Original Document at: http://www.ca.sandia.gov/casite/gupta/appendix.html

Paper Sections Paper Indices

Table of
Contents Appendices
Last
Page

Appendices

APPENDIX A

Calculating the Direction of the Shadows in the Helicopter Photo of the May 18, 1974 Subsidence Crater

APPENDIX B

Locating the Control Point for the May 18, 1974 Nuclear Test

APPENDIX C

Assessing the Credibility of the News Reports on Alleged Indian Nuclear Test Activity

APPENDIX D

Compiling a Table of Suppositions from the Collected Evidence on the Khetolai Military Range

APPENDIX A

Calculating the Direction of the Shadows in the Helicopter Photo of the May 18, 1974 Subsidence Crater

The January 1975 IAEA proceedings on peaceful nuclear explosions contain a technical paper by R. Chidambaram and R. Ramanna that describes India's 1974 nuclear test. The paper includes a photograph of the subsidence crater that formed shortly after the nuclear explosion (see plates 1 and 4). The caption under the picture states that the photo was "taken from a helicopter on 18 May 1974, soon after the experiment." [84] Near the end of the paper, the authors state that the helicopter observation of the crater was made "an hour after the experiment had taken place." [85] Thus, the aerial photo must have been taken at this time.

Using the published information on the helicopter photo as well as the seismic data from the Indian nuclear test, the direction of the photographed shadows was calculated. The shadow orientation was needed in order to establish the bearing of the helicopter-borne camera at the time the picture was taken. This information was then used to render the May 24, 1992 KVR-1000 satellite image as a perspective view that replicated the aerial camera geometry (see plates 4 and 5).

At 0 hrs ephemeris time on the day of the Indian nuclear test, the sun was located at the following equatorial coordinates: [86]

(A-1)

(A-2)

where

The apparent declination is measured with respect to the Earth's equatorial plane. The apparent right ascension is measured with respect to the first point of Aries - a vector oriented along the intersection of the Earth's equatorial plane and the Earth's orbital plane pointing at the sun on the vernal equinox.

According to the seismic data reported by the International Seismological Center, the nuclear explosion took place at 26.99±.028° N, 71.80±.033° E. The time of detonation was 02:34:55.40±.17 GMT on May 18, 1974. The helicopter observation was made one hour after the nuclear test so the aerial photo must have been taken at approximately 03:35 hrs GMT. To relate this time with the sun's position in the sky, the photo acquisition time was converted to local sidereal time (LST), which is the time at a specific point on the Earth measured with respect to the periodic motion of the distant stars in the sky. Time in GMT can be converted to LST in two steps: [87]

(A-3)

(A-4)

where

Table A.1 lists the value of each input parameter for equations A-3 and A-4 that was needed to convert the acquisition time of the helicopter photo to decimal hours LST.

(A-5)

Table A.1: Value of input parameters for equations A-3 and A-4 that pertain to the acquisition time of the helicopter photo and the location of the subsidence crater. The values were derived from the Chidambaram and Ramanna paper, the May 1974 ISC Seismological Bulletin, and the 1974 Ephemeris Almanac.

To relate this LST value at the estimated 1974 test location with the sun's position, the hour-angle, H, was calculated. H is the angular distance at a specific point on the Earth from the local meridian to an object's apparent right ascension. [88] It can be calculated by using the following equation:

(A-6)

Using the numbers from equations A-2 and A-5, [89]

(A-7)

Equation A-7 represents the hour-angle between the seismically estimated meridian of the photographed crater and the sun's longitude at the time the picture was taken. Using this hour-angle value, the sun's elevation and azimuth were calculated: [90]

(A-8)

(A-9)

where

Table A.2 lists the value of each input parameter for equations A-8 and A-9 that was needed to calculate the sun's elevation and azimuth at the instant the helicopter photo of the subsidence crater was acquired.

(A-10)

(A-11)

Table A.2: Value of input parameters for equations A-8 and A-9 that pertain to the acquisition time of the helicopter photo and the location of the subsidence crater. The values were derived from the Chidambaram and Ramanna paper, the May 1974 ISC Seismological Bulletin, and the 1974 Ephemeris Almanac.

Measured clockwise from north, the azimuth angle of 86.83° indicates that the sun was positioned approximately due east of the subsidence crater when the aerial picture was taken, and the bush shadows shown in the foreground of the photo cast westward towards the camera (see plates 1 and 4). Thus, the helicopter-borne camera must have been positioned west of the 1974 test location and pointed east to acquire the picture of the crater shortly after the nuclear explosion.

APPENDIX B

Locating the Control Point for the May 18, 1974 Nuclear Test

The control point for the May 18, 1974 nuclear test was located after a reexamination of the 1975 technical paper by Chidambaram and Ramanna. [91] This paper was revisited because of the new vehicle tracks around the 1974 test location that were observed in the 1996 SPOT satellite images. The two historical pictures in the paper were analyzed for topographic clues that could help explain why there was renewed activity around the old nuclear test site. The camera position and orientation for the ground photo and helicopter photo were determined and then compared with the ground shown in the 1996 SPOT images. The comparison did not yield a conclusive explanation for the new activity. However, the combination of the oriented ground photo with the ancillary descriptions in the text did reveal the location of the 1974 control point.

Plate B.1 shows the ground photo which was acquired as the underground explosion displaced the surface upward. The caption describes the picture as a "[p]hotograph of the mound near its peak position as taken from the control point." [92] In the picture, the cable line and adjacent road can be seen leading to the explosion site in the distance. The picture also shows a desert tree in the foreground as well as tire tracks that veer off the main dirt road leading to the camera's location at the control point.

Plate B.1: Photo of the 1974 underground nuclear explosion displacing the surface upward. The picture was taken at the control point. It shows the mound in the distance as well as the cable line and road leading to the explosion site. It also shows a desert tree in the foreground and tire tracks that lead to the control point. (Source: Chidambaram and Ramanna, "Some Studies on India's Peaceful Nuclear Explosion Experiment," p. 430.)

The presence of the cable line and camera suggests that the control point was used for firing the nuclear device and observing the explosion. The control point was also used for monitoring radioactive fallout; one of two health physics laboratories was stationed there. [93] In addition, deposition trays and health physics survey teams were dispersed throughout the area. Figure B.1 shows a diagram from the Chidambaram and Ramanna paper that maps the location of the deposition trays and health physics survey teams relative to the 1974 explosion site.

Figure B.1: Location of the deposition trays and health physics survey teams relative to the 1974 explosion site. The wind rose in the lower left corner shows the wind conditions shortly before the nuclear test was conducted. (Source: Chidambaram and Ramanna, "Some Studies on India's Peaceful Nuclear Explosion Experiment," p. 426.)

The paper does not provide the exact location of the control point. However, if one presumes that the health physics laboratory at the control point contained deposition trays or was occupied by a health physics survey team, the control point can reasonably be inferred to be one of the nine radioactive monitoring stations mapped in figure B.1. The nine candidate control points can be whittled down to one through a photogrammetric process of elimination. Each prospective control point can be compared with the camera and shadow orientation shown in the ground photo that was taken at the actual control point (see plate B.1). If one of the radioactive monitoring stations is indeed the control point, it would have to fit the optical geometry of the ground photo. [94]

The ground photo has two photogrammetric characteristics that define its orientation: the line-of-sight to the explosion and the direction of the shadows. The former is given in figure B.1 for each of the nine prospective control points. The latter can be seen at a desert tree in the foreground of the picture (see plate B.1), and calculated from the photo acquisition time and geographic coordinates of the 1974 explosion site. The photo acquisition time corresponds with the approximate time of detonation, since the picture shows the near instantaneous surface rise from the explosion: 02:34:55.40 ±.17 GMT on May 18, 1974. [95] The geographic coordinates of the 1974 ground zero were obtained from the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image: 27.095 ±.001° N, 71.752 ±.001° E (see plate 5). With these input parameters, the direction of the tree shadow was calculated by sequentially applying equations A-3, A-4, A-6, A-8, and A-9 (see Appendix A). Table B.1 lists the value of each input parameter for these equations in the appropriate units. The calculation yielded the following values for the sun's elevation and azimuth at the instant the ground photo of the explosion was acquired:

(B-1)

(B-2)

where

Table B.1: Value of input parameters for equations A-3, A-4, A-6, A-8, and A-9 that pertain to the acquisition time of the ground photo (Plate B.1) and photogrammetric location of the May 18, 1974 test. The values were derived from the Chidambaram and Ramanna paper, the May 1974 ISC Seismological Bulletin, the 1974 Ephemeris Almanac, and the satellite image analysis.

Measured clockwise from north, the azimuth angle of 81.03° indicated that the sun was located east-northeast of the control point when the ground photo was taken, and the tree trunk shadow pointing to the left side of the photo cast towards the west-southwest. Given this directional indicator, the camera at the control point must have been located south of the 1974 test location. This finding eliminated six of the nine candidate control points shown in figure B.1; only stations 2, 4, and 5 were located south of the explosion site. The pool of possible control points was reduced further by calculating - the clockwise angular distance from the shadow vector to the line-of-sight vector - for each of the three remaining stations and comparing the results with the ground photo (see plate B.2 inset). Plate B.2 shows that the calculated value at station 4 was the only one that matched the actual value of the ground photo. Thus, station 4 was the control point for the 1974 nuclear test, and it was located approximately 4.8 km southeast of the detonation point at an azimuth angle of 156° (see figure B.1 and plate 16).

Plate B.2: Ground photo of mound with tree shadow vector and line-of-sight vectors for stations 2, 4, and 5. The inset shows the values - the clockwise angular distance from the shadow vector to the line-of- sight vector - for stations 2, 4, and 5. Projected onto the ground with respect to the shadow line from the vertical tree trunk, the line-of-sight vector from station 4 was the only one that pointed along the line-of-sight of the camera towards the explosion site. This conclusively established station 4 as the 1974 control point.

APPENDIX C

Assessing the Credibility of the News Reports on Alleged Indian Nuclear Test Activity

Following the image analysis, the credibility of each news report on alleged Indian nuclear test activity was checked by comparing the factual claims with the image-derived information. If a specific factual claim in a news report was corroborated or consistent with the image-derived information, it was assigned a '+' indicator. If the claim was inconsistent with the imagery, it was assigned a '-' indicator. If a factual statement was checked with overhead imagery and the result was inconclusive, it was given a '*' indicator. Other articles that could be linked to these factual claims were also assigned the corresponding indicators. The total number of the three indicators for each article provided a semi-quantitative way of assessing the believability of other factual claims in the article that could not - for purely technical reasons - be checked with the available commercial satellite imagery.

For example, consider the January 1, 1996 Business Standard article by Damandeep Singh. This article made six factual claims:

A new fence was built around the 1974 nuclear test site.

Cattle routinely grazed around the 1974 test site.

The 1974 test site was located around four kilometers down a sandy trail off the main road just before one nears Loharki village.

In 1995, locals "had not seen any earthmoving or civil construction activity."

Locals remember that the "grass and shrubs in the area were burnt" shortly after the 1974 nuclear test.

In the fall of 1995, locals had seen army exercises that were the "biggest ever witnessed by them."

The first claim was verified in the March 1996 SPOT images, which show a new, light-toned ring around the 1974 subsidence crater, and in the March 6, 1996 Radarsat image which shows a circular arc along the periphery of the crater. The second claim was supported by all of the SPOT images which show differential vegetation growth near the 1974 test site, indicating livestock grazing outside the fenced area. The third claim was confirmed by the March 25, 1995 SPOT image, which shows the 1974 test site located approximately four kilometers off the main road to Loharki. The fourth claim was refuted by the March 1996 SPOT images which show perimeter reinforcement and extensive ground clearing in the immediate vicinity of the 1974 test site. The fifth and sixth claim could not be verified because the satellite imagery did not date back to 1974, and because the new imagery was too coarse in spatial resolution to show personnel and vehicles. However, both facts were deemed as believable because the article made three obscure factual claims that were independently verified and only one claim that proved to be incorrect.

Table C.1 lists the results from the credibility assessment. For each news article, the table lists the factual claims that could be checked with the satellite imagery and compares each claim with the image-derived information. The verified facts and believable claims were then incorporated into the table of suppositions (see Appendix D) and the Venn diagram (see figure 3).

Table C.1: Credibility Assessment of News Reports Using Image-Derived Information

News Report Factual Claims Image-Derived Evidence

Senator Alan Cranston, "Nuclear Arms Race in South Asia Endangers US Security Interests," Congressional Record, US Senate, April 27, 1981, pp. 7375-7377. "The Indian test site involves surface excavations for burial of a nuclear warhead - for an underground test - and has been under preparation for several months in the [T]har Desert at Pokharan. It is alongside the site of India's 1974 bomb test, approximately 100 miles southeast of the Pakistani border." + This statement is consistent with the May 5, 1981 Indian Express article and the May 9-15, 1982 Sunday Magazine article - two reports with factual claims that were verified by the satellite image analysis.

Rahul Bedi, "Pokhran Full of N-Test Talk," Indian Express, May 5, 1981, p. 1. "Around the early 1960s over 20 villages in the Pokhran tehsil were taken over by the army and the area closed to the public." + Analysis of the December 12, 1961 KH-3 image and the March 25, 1995 SPOT image revealed that a large tract of land northwest of Pokharan had been taken out of farm production and taken over by the military (see plates 6 and 7).
The May 24, 1992 KVR-1000 image shows that Malka village ceased to exist. Analysis of the May 24, 1992 KVR-1000 image, the March 25, 1995 SPOT image, and the March 6, 1996 Radarsat image indicate that Nautala village was abandoned.

"However, as the area is drought-prone, and sheep-rearing is the mainstay of the villagers, the Bishnois would take livestock to the wells of the acquired villages within the forbidden area with official connivance." + The March 25, 1995 SPOT image shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13)

"The deputy sarpanch said that barbed wire fencings suddenly went up three months ago around three kilometres south of the old blast site, which is part of the Pokhran firing range for tanks and artillery, enclosing an area roughly eight kms long and three kms wide." + South of the 1974 subsidence crater next to the tank firing ranges and conventional target areas, the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a fenced area (see plates 7 and 13). The area is secured by a triangular-shaped perimeter with a base and height of 5.7 km and 6.1 km respectively.

Shubhabrata Bhattacharya, "Another Nuclear Blast at Pokhran?," Sunday Magazine, Calcutta, May 9-15, 1982, pp. 12-15. "The site was chosen sometime after the 1965 Indo-Pak war and in 1969 two villages, Malka and Kala, were evacuated to make way for the field firing range. Later, four more villages - Naotala, Etah, Taorki, and Sudhia - were also similarly evacuated around 1971." + The May 24, 1992 KVR-1000 image shows that Malka village ceased to exist. Analysis of the May 24, 1992 KVR-1000 image, the March 25, 1995 SPOT image, and the March 6, 1996 Radarsat image indicate that Nautala village was abandoned.

"The 1974 explosion was carried out near the abandoned Malka village which is located about four km away from Loharki, a village on the Ramdeora-Nachna road." + The May 24, 1992 KVR-1000 image and the 1955 US AMS map sheet (NG-42-04) confirmed that the May 18, 1974 nuclear test took place at Malka - just 1.5 km southwest of the village center.

They [the Loharki villagers] said that for the past one year the army had cordoned off an area between the earlier test site of Malka and Khetolai..." + Between the May 18, 1974 crater and Khetolai, the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a cordoned area (see plates 7 and 13).

"UNI Correspondent Visits Pokhran A-Blast Site," Patriot, New Delhi, January 17, 1983, p. 7. "A UNI correspondent who recently visited the [1974 test] site situated about 20 km from Pokharan town saw no sign of life except stray crows and grazing goats." + The March 25, 1995 SPOT image shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13).
+ The May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image indicate that the 1974 test site is about 20 km from Pokharan town. To be exact, it is 24.8 km away.

"The underground explosion which catapulted India to nuclear might made a huge crater about 60 feet in diameter." - Analysis of the May 24, 1992 KVR-1000 image of the 1974 subsidence crater revealed a crater diameter of approximately 165 meters - not 60 feet.

Tim Weiner, "India Suspected of Preparing for A-Bomb Test," New York Times, December 15, 1995, p. A6. US spy satellites had "recorded scientific and technical activity at the Pokharan test site in the Rajasthan Desert." * The described activity was too vague in detail and location to verify with the commercial satellite imagery.

R. Jeffrey Smith, "Possible Nuclear Arms Test by India Concerns US," Washington Post, December 16, 1995, p. A17. "The [Pokharan] site has been routinely maintained by India for the past two decades, but US intelligence officials recently noted efforts to clean out a deep underground shaft for lowering a nuclear weapon into the earth." * The spatial and temporal resolution of the 1996 SPOT and Radarsat imagery was too coarse to determine whether the described activity took place. In addition, the described location of the alleged activity was too vague to verify with the commercial satellite imagery.

"They also noted 'possible preparation for instrumentation' of a blast to determine whether it occurred as predicted," the official said. * The spatial and temporal resolution of the 1996 SPOT and Radarsat imagery was too coarse to determine whether the described "possible" activity took place. In addition, the described location of the alleged activity was too vague to verify with the commercial satellite imagery.

M.D. Nalapat, "Defense Officials Upset over Report on N-test," The Times of India, Bombay, December 18, 1995, p. 1. "Senior [Indian] defense officials claim that the Clinton Administration had made available satellite data to selected US correspondents without informing them that Pokhran has four ranges: A, B, C, and D. And of the four, only range A is meant for nuclear experiments 'and here there has been no activity.'" + The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10). The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both.

According to these officials, the activity mentioned by the spy satellites was taking place in range B and C, 'which are used by the army.' These ranges, along with range D (used by the air force) 'have been the site of exercises for many years, and there is nothing unusual in this.'" - The March 2, 1996 and March 18, 1996 SPOT images show large-scale, unusual activity in the immediate vicinity of the 1974 nuclear explosion site (see plates 16 and 18). So, either the article's claim of no activity at the site for nuclear experiments is incorrect, or the article is referring to another site near Pokharan that is reserved for nuclear experiments.

"Using a Pretext of the Nuclear Test," Jansatta, Delhi, December 19, 1995, p. 6. "The areas that the US satellite has been photographing in Pokaran is the arena where Indian forces go to conduct their practice exercises. The actual site reserved for the nuclear explosions does not appear in the photographs at all as it is devoid of any activity." + The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10). The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both.
- The March 2, 1996 and March 18, 1996 SPOT images show large-scale, unusual activity in the immediate vicinity of the 1974 nuclear explosion site (see plates 16 and 18). So, either the article's claim of no activity at the site for nuclear experiments is incorrect, or the article is referring to another site near Pokharan that is reserved for nuclear experiments.

Pravin Sawhney, "Preparations at Pokharan Site Reportedly for Missile Test," The Asian Age, Delhi, December 19, 1995, pp. 1, 4. "The Pokharan range is divided into four parts: range A for artillery firing which needs a maximum open area of 40 km, range B is traditionally for armour exercises, range C is for the Indian air force and range D, where the 1974 peaceful nuclear implosion was conducted, is cordoned off as restricted area." + The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10).
+ The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both.

"The only normal activity at range D is the movement of a few security guards and an engineer platoon of the army. Scientists are known to move in and out of this area, but the overall activity is minimal. Now with India planning to test Prithvi there, the activity at D range has picked up." + The May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a cordoned area adjacent to the 1974 explosion site. The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.
+ Analysis of the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image indicated that no large-scale changes took place in the vicinity of the 1974 test site over the three year period. The March 2, 1996 and March 18, 1996 SPOT images show extensive activity in this area since March 1995.

Prem Shankar Jha, "Maintaining India's Nuclear Option," The Hindu, Madras, December 30, 1995, p. 12. "An Indian correspondent who visited Pokaran and talked to the villagers in adjoining villages has reported that a new barbed wire fence now rings off the vast site of the 1974 test, that there is evidence of earth moving equipment having been used and that villagers claim that an entire new hill has been created from the excavated sand and mud. However, he also reports that electrical wiring conduits that the Americans claim to have seen, may have been a water pipe laid to one of the villages." + The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.
+ Analysis of the March 2, 1996 and March 18, 1996 SPOT images revealed that earthmoving equipment was used to build new security perimeters as well as several new linear traces.

* No evidence of a new hill of excavated sand and mud was found in any of the images.

* No evidence of a water pipe leading to one of the nearby villages was found in any of the images.

Damandeep Singh, "Heavy Military Build-Up Near First Nuclear Explosion Site," Business Standard, Dehli, January 1, 1996, pp. 1, 3. "Villagers in nearby Loharki, however, point to two odd happenings - army build-up in the region in recent weeks on a scale not seen before and a new, sturdy fence that has come up, around the old [test] site." + The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.

"Loharki's residents also find it hard to explain the emergence of the fence. A sandy trail, marked with fresh tyre tracks, leads off just before one nears the village, with the [1974] site located around four km down the trail." + Analysis of the SPOT images revealed that the article accurately described the location of the 1974 test site from the main road that links with Loharki village.

"Pancha Ram, a Loharki farmer, finds this surprising as villagers have been using the area in and around the site for grazing their cattle." + The March 25, 1995 SPOT images shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13).

"They [the villagers] had not seen any large-scale earthmoving or civil construction activity." - Analysis of the March 2, 1996 and March 18, 1996 SPOT images revealed that large-scale earthmoving and civil construction did take place approximately 8.5 kilometers south-southwest of Loharki village. The activity involved the construction of new security perimeters and linear traces.

P.R. Chari, "Reports of Test Forcing Nuclear Decision," The Hindustan Times, Delhi, January 3, 1996, p. 11. "These activities comprised fencing off the old test site, piling up earth to construct a huge sand dune, laying down cables, and so on." + The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.

* No evidence of a new huge sand dune was found in any of the images.

W.P.S. Sidhu, "India's Nuclear Tests: Technical and Military Imperatives," Jane's Intelligence Review 8 (4), April 1996, pp. 170-173. "Besides, senior nuclear scientists have revealed that open-source reports about India's preparations for nuclear tests in the early 1980s were accurate." + This statement is consistent with the May 5, 1981 Indian Express article and the May 9-15, 1982 Sunday Magazine article - two reports that contain factual claims that were verified by the satellite image analysis.

APPENDIX D

Compiling a Table of Suppositions from the Collected Evidence on the Khetolai Military Range

The collected evidence conclusively proved that large-scale, unusual activity did take place at the Khetolai military range. With that fact established, each item of evidence was examined to determine whether the observed activity was conventional exercises, nuclear test preparations, Prithvi field testing, or something completely different. The analysis was done by tabulating a list of suppositions - a series of propositions that explained how each item of evidence could be attributed to at least one of the four activities. Table D.1 lists the collected evidence and the various explanations for it. To determine what kind of activity actually took place at the Khetolai military range, each item of evidence was placed onto a Venn diagram based on the enumerated suppositions (see figure 3), and then analyzed for spatial and logical relationships that were characteristic of at least one of the four possible activities.

Table D.1: Table of Suppositions from the Collected Evidence on the Khetolai Military Range

Evidence Conventional Military Exercises Innocuous Activity Nuclear Test Activity Prithvi-1 Field Testing

New fence around the May 18, 1974 subsidence crater Could have been erected as a safety measure to prevent mechanized units, on daytime or nighttime maneuvers, from accidently falling into the crater. Could have been constructed immediately after the initial allegations of nuclear test preparations were made in order to prevent news reporters from descending into the hazardous crater area. Could have been built to secure the site for new post-test experiments and training exercises that would prepare personnel for future nuclear tests. Could have been erected as a safety measure to prevent Prithvi missile units, on daytime or nighttime maneuvers, from accidently falling into the crater.

Concentration of vehicle tracks next to the 1974 test site proceeding ~ 4 km towards the southeast Could be the surface markings left by mechanized units practicing maneuvers in the open area. The concentration of vehicle tracks next to the 1974 test site could have been the assembly point. Could be the tread marks left by military patrols that were sent out to keep the media away from conventional military areas. The concentration of vehicle tracks next to the 1974 test site could be a makeshift guard post. Could be evidence of survey work for an underground nuclear test. The concentration of vehicle tracks next to the 1974 test site could be the planned ground zero. The tracks towards the southeast could be the planned cable route to the control point, which would be positioned in the same relative location as the 1974 control point. Could be the tracks left by Prithvi transporter-erector-launchers (TELs) that performed off-road mobility tests in the open desert.

"...soon after the first [1974] explosion, grass and shrubs in the area were burnt..." Singh, Business Standard, 1/1/96, pp. 1, 3, + + + - Since the 1974 test was conducted in the vicinity of established conventional test ranges, it is possible the area was burnt because of live munition firing during conventional exercises that happened after the 1974 nuclear test. The grass and shrubs in the area may have been burnt by accident. Brush fires are common in arid regions with seasonal vegetation growth. The grass and shrubs may have been burnt deliberately as part of a post-test experiment. The control burn could have been done in order to determine how abrupt ground motion and radioactive leakage from the 1974 nuclear test affected the regrowth of natural vegetation. N/A. The Prithvi missile program did not even exist in 1974.

Two brush fires that happened after March 25, 1995 May have been caused by live munition firing in the area during conventional exercises. Alternatively, the fires may have been deliberately set to train troops for operations in a smoke-filled environment. The fires started along the new security perimeter (see plate 16). The cause may have been two separate accidents that happened during the construction of the new security perimeter. May have been set to clear vegetation before a planned nuclear test. The cleared ground could then be used as a study area to determine how abrupt ground motion and radioactive leakage affected the regrowth of natural vegetation. May have been a fire control exercise to train personnel in brush fire containment following a Prithvi field test or launch mishap.

Biggest military exercises every witnessed by locals. Singh, Business Standard, 1/1/96, pp. 1, 3, + + + - Could have simply been the largest conventional military exercises that have ever been staged in the Pokharan area. N/A. Could have been larger than usual because additional personnel and equipment were needed to prepare an underground nuclear test in conjunction with the routine conventional exercises. Could have been larger than usual because Prithvi missile batteries and support units were added to the regular complement of army regiments.

Road link to/from military base located 4.0 km to the southwest. Could be the main route for mechanized units to reach the military range for conventional exercises. N/A. Could exist so that the nearby mechanized units can provide physical security for the nuclear test site. The site is only 90 km from the border with Pakistan. Could be used by the nearby mechanized units for participating in coordinated exercises with the Prithvi missile units.

New vehicle tracks to/from Nautala conventional target areas Could be the tread marks left by artillery units based inside the secured area. Also could be tracks left by mechanized units from the military armor base. N/A. Could have been an indirect route for personnel and equipment to get to and from the nuclear test site via the conventional testing grounds. By entering and exiting the conventional ranges, the locals would have interpreted the activity as routine military exercises. Could be the tread marks left by Prithvi transporter-erector-launchers (TELs) that performed off-road mobility tests in the open desert.

5/18/74 crater with cable line connecting it to the control point 4.8 km southeast of the ground zero N/A. N/A. The crater was created by an underground nuclear explosion. The cable line was oriented perpendicular to the prevailing wind direction. The control point was used for firing the nuclear device, observing the explosion, and monitoring for radioactive release. N/A.

Surface excavations for burial of nuclear warhead. Senator Cranston, 4/27/81, + N/A. N/A. The Senator's description of surface excavations for burial of a nuclear warhead can only be construed as nuclear test preparations. N/A.

Village leaders' reports of evacuation plans and new security perimeter. Bedi, Indian Express, 5/5/81, p. 1, + + + N/A. N/A. The official notification of a four-day evacuation plan for nine neighboring villages could have been a safety measure to protect villagers from the earthquake- like ground shock and inadvertent radioactive release from a planned underground nuclear test. N/A. The Prithvi missile program did not exist in 1981.

Nighttime operation of a machine that sounded like a drill. Bhattacharya, Sunday Magazine, May 9-15, 1982, pp. 12-15. + + + N/A. N/A. The nighttime operation of a machine that sounded like a drill could have been a concerted effort to prepare the ground for underground nuclear testing. N/A. The Prithvi missile program did not exist in 1982.

In the early 1980s, two holes were completed for future nuclear tests. Sidhu, Jane's Intelligence Review, 4/96, pp. 170-173. + N/A. N/A. The two holes can plausibly be considered the result of the activity that was observed and reported in 1981 and 1982 by Senator Cranston, local villagers, and village leaders. N/A.

Prithvi-1 mobility and preparation exercises, Sawhney, Asian Age, 12/19/95, pp. 1, 4. + + + + N/A. N/A. N/A. As described in the article, the activity around the 1974 nuclear test site could have been Prithvi-1 mobility and preparation exercises under field conditions.

Prospective impact points in several military operation areas located > 40 km and < 150 km away. N/A. N/A. N/A. The March 1991 1:500,000 scale Tactical Pilotage Chart (H-8C) shows five military operation areas that could be used as impact points for Prithvi field tests. From the 1974 nuclear test site, the Prithvi-1 could reach targets in these areas at its minimum range (40 km) and maximum range (150 km).

Multiple perimeter barriers N/A. N/A. At least four layers of security barriers surround the sites in the center of the military range. The reinforcement of these barriers may have been done to secure the sites for the delivery and underground placement of nuclear test devices. At least four layers of security barriers surround the sites in the center of the military range. The reinforcement of these barriers may have been done to secure the sites for the delivery and temporary deployment of Prithvi-1 test missiles.

Laid out cables. Chari, Hindustan Times, 1/3/96, p. 11. + * N/A. N/A. The cables could have been laid out to fire the nuclear test device and collect data from the nuclear explosion. The cables could have been laid out to connect the field launch point with the Prithvi transporter-erector-launcher (TEL). Cables are routinely used worldwide for such mobile missile launches.

Identical rectangular structures at sites A and C connected to branches AF and CE which link with line EG and end at point G (see plates 18 and 19) N/A. The multiple perimeter barriers suggest that the activity inside the secured area was not routine conventional exercises. N/A. The linear traces could be cable lines connecting the control point (Point G) with the two shafts that were prepared in the early 1980s (the rectangular structures at sites A and C). As in 1974, the cable link (line EG) is oriented perpendicular to the prevailing winds, which would keep radioactive fallout away from the control point. (See figure 4.) The linear traces could be road transport links connecting the missile launch point (Point G) to the two buildings for housing the Prithvi missiles and volatile fuel supply (the rectangular structures at sites A and C). The road link (line EG) is 2.1 km long so test launches could be done at a safe distance from the basing areas. It is oriented perpendicular to the prevailing winds, which would keep the toxic exhaust plume away from the basing areas. (See figure 5.)

Sites B and D connected to branches BF and DF which link with line EG and end at point G (see plates 18 and 19) N/A. N/A. Site B is equidistant from the two inferred shaft locations (sites A and C). Thus, it could be a diagnostics station for recording the data that would be transmitted via cable from both explosion sites. Line BG could be a cable link from site B to the control point (Point G). Site B is equidistant from the two inferred Prithvi storage facilities and is connected to the inferred launch point (Point G). Thus, it could be the missile control point for coordinating the deployment of Prithvi units to the launch point, tracking the missile after launch, and communicating with the impact site.

Site D is located near the entrance to the central secured area. It could be a support base for nuclear test preparations with a new road link to the control point (Point G). (See figure 4.) Site D is located near the entrance to the central secured area. It could be a support base for Prithvi field tests with a new road link to the launch point (Point G). (See figure 5.)

Paper Sections Paper Indices

Table of
Contents Appendices
Last
Page

Paper by: Vipin Gupta and Frank Pabian
Webmaster

SAND 96-8252W


News Report	Factual Claims	Image-Derived Evidence
Senator Alan Cranston, "Nuclear Arms Race in South Asia Endangers US Security Interests," Congressional Record, US Senate, April 27, 1981, pp. 7375-7377.	"The Indian test site involves surface excavations for burial of a nuclear warhead - for an underground test - and has been under preparation for several months in the [T]har Desert at Pokharan. It is alongside the site of India's 1974 bomb test, approximately 100 miles southeast of the Pakistani border."	+ This statement is consistent with the May 5, 1981 Indian Express article and the May 9-15, 1982 Sunday Magazine article - two reports with factual claims that were verified by the satellite image analysis.

Rahul Bedi, "Pokhran Full of N-Test Talk," Indian Express, May 5, 1981, p. 1.	"Around the early 1960s over 20 villages in the Pokhran tehsil were taken over by the army and the area closed to the public."	+ Analysis of the December 12, 1961 KH-3 image and the March 25, 1995 SPOT image revealed that a large tract of land northwest of Pokharan had been taken out of farm production and taken over by the military (see plates 6 and 7). The May 24, 1992 KVR-1000 image shows that Malka village ceased to exist. Analysis of the May 24, 1992 KVR-1000 image, the March 25, 1995 SPOT image, and the March 6, 1996 Radarsat image indicate that Nautala village was abandoned.
	"However, as the area is drought-prone, and sheep-rearing is the mainstay of the villagers, the Bishnois would take livestock to the wells of the acquired villages within the forbidden area with official connivance."	+ The March 25, 1995 SPOT image shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13)
	"The deputy sarpanch said that barbed wire fencings suddenly went up three months ago around three kilometres south of the old blast site, which is part of the Pokhran firing range for tanks and artillery, enclosing an area roughly eight kms long and three kms wide."	+ South of the 1974 subsidence crater next to the tank firing ranges and conventional target areas, the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a fenced area (see plates 7 and 13). The area is secured by a triangular-shaped perimeter with a base and height of 5.7 km and 6.1 km respectively.

Shubhabrata Bhattacharya, "Another Nuclear Blast at Pokhran?," Sunday Magazine, Calcutta, May 9-15, 1982, pp. 12-15.	"The site was chosen sometime after the 1965 Indo-Pak war and in 1969 two villages, Malka and Kala, were evacuated to make way for the field firing range. Later, four more villages - Naotala, Etah, Taorki, and Sudhia - were also similarly evacuated around 1971."	+ The May 24, 1992 KVR-1000 image shows that Malka village ceased to exist. Analysis of the May 24, 1992 KVR-1000 image, the March 25, 1995 SPOT image, and the March 6, 1996 Radarsat image indicate that Nautala village was abandoned.
	"The 1974 explosion was carried out near the abandoned Malka village which is located about four km away from Loharki, a village on the Ramdeora-Nachna road."	+ The May 24, 1992 KVR-1000 image and the 1955 US AMS map sheet (NG-42-04) confirmed that the May 18, 1974 nuclear test took place at Malka - just 1.5 km southwest of the village center.
	They [the Loharki villagers] said that for the past one year the army had cordoned off an area between the earlier test site of Malka and Khetolai..."	+ Between the May 18, 1974 crater and Khetolai, the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a cordoned area (see plates 7 and 13).

"UNI Correspondent Visits Pokhran A-Blast Site," Patriot, New Delhi, January 17, 1983, p. 7.	"A UNI correspondent who recently visited the [1974 test] site situated about 20 km from Pokharan town saw no sign of life except stray crows and grazing goats."	+ The March 25, 1995 SPOT image shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13). + The May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image indicate that the 1974 test site is about 20 km from Pokharan town. To be exact, it is 24.8 km away.
	"The underground explosion which catapulted India to nuclear might made a huge crater about 60 feet in diameter."	- Analysis of the May 24, 1992 KVR-1000 image of the 1974 subsidence crater revealed a crater diameter of approximately 165 meters - not 60 feet.

Tim Weiner, "India Suspected of Preparing for A-Bomb Test," New York Times, December 15, 1995, p. A6.	US spy satellites had "recorded scientific and technical activity at the Pokharan test site in the Rajasthan Desert."	* The described activity was too vague in detail and location to verify with the commercial satellite imagery.

R. Jeffrey Smith, "Possible Nuclear Arms Test by India Concerns US," Washington Post, December 16, 1995, p. A17.	"The [Pokharan] site has been routinely maintained by India for the past two decades, but US intelligence officials recently noted efforts to clean out a deep underground shaft for lowering a nuclear weapon into the earth."	* The spatial and temporal resolution of the 1996 SPOT and Radarsat imagery was too coarse to determine whether the described activity took place. In addition, the described location of the alleged activity was too vague to verify with the commercial satellite imagery.
	"They also noted 'possible preparation for instrumentation' of a blast to determine whether it occurred as predicted," the official said.	* The spatial and temporal resolution of the 1996 SPOT and Radarsat imagery was too coarse to determine whether the described "possible" activity took place. In addition, the described location of the alleged activity was too vague to verify with the commercial satellite imagery.

M.D. Nalapat, "Defense Officials Upset over Report on N-test," The Times of India, Bombay, December 18, 1995, p. 1.	"Senior [Indian] defense officials claim that the Clinton Administration had made available satellite data to selected US correspondents without informing them that Pokhran has four ranges: A, B, C, and D. And of the four, only range A is meant for nuclear experiments 'and here there has been no activity.'"	+ The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10). The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both.
	According to these officials, the activity mentioned by the spy satellites was taking place in range B and C, 'which are used by the army.' These ranges, along with range D (used by the air force) 'have been the site of exercises for many years, and there is nothing unusual in this.'"	- The March 2, 1996 and March 18, 1996 SPOT images show large-scale, unusual activity in the immediate vicinity of the 1974 nuclear explosion site (see plates 16 and 18). So, either the article's claim of no activity at the site for nuclear experiments is incorrect, or the article is referring to another site near Pokharan that is reserved for nuclear experiments.

"Using a Pretext of the Nuclear Test," Jansatta, Delhi, December 19, 1995, p. 6.	"The areas that the US satellite has been photographing in Pokaran is the arena where Indian forces go to conduct their practice exercises. The actual site reserved for the nuclear explosions does not appear in the photographs at all as it is devoid of any activity."	+ The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10). The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both. - The March 2, 1996 and March 18, 1996 SPOT images show large-scale, unusual activity in the immediate vicinity of the 1974 nuclear explosion site (see plates 16 and 18). So, either the article's claim of no activity at the site for nuclear experiments is incorrect, or the article is referring to another site near Pokharan that is reserved for nuclear experiments.

Pravin Sawhney, "Preparations at Pokharan Site Reportedly for Missile Test," The Asian Age, Delhi, December 19, 1995, pp. 1, 4.	"The Pokharan range is divided into four parts: range A for artillery firing which needs a maximum open area of 40 km, range B is traditionally for armour exercises, range C is for the Indian air force and range D, where the 1974 peaceful nuclear implosion was conducted, is cordoned off as restricted area."	+ The March 25, 1995 SPOT image shows tank firing ranges northwest of Pokharan (see plate 10). + The May 24, 1992 KVR-1000 image shows two conventional target areas just north of the tank firing ranges (see plate 11). The numerous craters in the target areas could have been the result of artillery firing, aerial bombardment, or both.
	"The only normal activity at range D is the movement of a few security guards and an engineer platoon of the army. Scientists are known to move in and out of this area, but the overall activity is minimal. Now with India planning to test Prithvi there, the activity at D range has picked up."	+ The May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image show a cordoned area adjacent to the 1974 explosion site. The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater. + Analysis of the May 24, 1992 KVR-1000 image and the March 25, 1995 SPOT image indicated that no large-scale changes took place in the vicinity of the 1974 test site over the three year period. The March 2, 1996 and March 18, 1996 SPOT images show extensive activity in this area since March 1995.

Prem Shankar Jha, "Maintaining India's Nuclear Option," The Hindu, Madras, December 30, 1995, p. 12.	"An Indian correspondent who visited Pokaran and talked to the villagers in adjoining villages has reported that a new barbed wire fence now rings off the vast site of the 1974 test, that there is evidence of earth moving equipment having been used and that villagers claim that an entire new hill has been created from the excavated sand and mud. However, he also reports that electrical wiring conduits that the Americans claim to have seen, may have been a water pipe laid to one of the villages."	+ The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater. + Analysis of the March 2, 1996 and March 18, 1996 SPOT images revealed that earthmoving equipment was used to build new security perimeters as well as several new linear traces. * No evidence of a new hill of excavated sand and mud was found in any of the images. * No evidence of a water pipe leading to one of the nearby villages was found in any of the images.

Damandeep Singh, "Heavy Military Build-Up Near First Nuclear Explosion Site," Business Standard, Dehli, January 1, 1996, pp. 1, 3.	"Villagers in nearby Loharki, however, point to two odd happenings - army build-up in the region in recent weeks on a scale not seen before and a new, sturdy fence that has come up, around the old [test] site."	+ The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.
	"Loharki's residents also find it hard to explain the emergence of the fence. A sandy trail, marked with fresh tyre tracks, leads off just before one nears the village, with the [1974] site located around four km down the trail."	+ Analysis of the SPOT images revealed that the article accurately described the location of the 1974 test site from the main road that links with Loharki village.
	"Pancha Ram, a Loharki farmer, finds this surprising as villagers have been using the area in and around the site for grazing their cattle."	+ The March 25, 1995 SPOT images shows differential vegetation growth at fence lines around military areas, indicating livestock grazing just outside the secured perimeter in abandoned areas such as Malka village and the 1974 subsidence crater (see plate 13).
	"They [the villagers] had not seen any large-scale earthmoving or civil construction activity."	- Analysis of the March 2, 1996 and March 18, 1996 SPOT images revealed that large-scale earthmoving and civil construction did take place approximately 8.5 kilometers south-southwest of Loharki village. The activity involved the construction of new security perimeters and linear traces.

P.R. Chari, "Reports of Test Forcing Nuclear Decision," The Hindustan Times, Delhi, January 3, 1996, p. 11.	"These activities comprised fencing off the old test site, piling up earth to construct a huge sand dune, laying down cables, and so on."	+ The March 2, 1996 SPOT image, the March 18, 1996 SPOT image, and the March 6, 1996 Radarsat image show a new fence around the 1974 subsidence crater.
		* No evidence of a new huge sand dune was found in any of the images.

W.P.S. Sidhu, "India's Nuclear Tests: Technical and Military Imperatives," Jane's Intelligence Review 8 (4), April 1996, pp. 170-173.	"Besides, senior nuclear scientists have revealed that open-source reports about India's preparations for nuclear tests in the early 1980s were accurate."	+ This statement is consistent with the May 5, 1981 Indian Express article and the May 9-15, 1982 Sunday Magazine article - two reports that contain factual claims that were verified by the satellite image analysis.


Evidence	Conventional Military Exercises	Innocuous Activity	Nuclear Test Activity	Prithvi-1 Field Testing
New fence around the May 18, 1974 subsidence crater	Could have been erected as a safety measure to prevent mechanized units, on daytime or nighttime maneuvers, from accidently falling into the crater.	Could have been constructed immediately after the initial allegations of nuclear test preparations were made in order to prevent news reporters from descending into the hazardous crater area.	Could have been built to secure the site for new post-test experiments and training exercises that would prepare personnel for future nuclear tests.	Could have been erected as a safety measure to prevent Prithvi missile units, on daytime or nighttime maneuvers, from accidently falling into the crater.

Concentration of vehicle tracks next to the 1974 test site proceeding ~ 4 km towards the southeast	Could be the surface markings left by mechanized units practicing maneuvers in the open area. The concentration of vehicle tracks next to the 1974 test site could have been the assembly point.	Could be the tread marks left by military patrols that were sent out to keep the media away from conventional military areas. The concentration of vehicle tracks next to the 1974 test site could be a makeshift guard post.	Could be evidence of survey work for an underground nuclear test. The concentration of vehicle tracks next to the 1974 test site could be the planned ground zero. The tracks towards the southeast could be the planned cable route to the control point, which would be positioned in the same relative location as the 1974 control point.	Could be the tracks left by Prithvi transporter-erector-launchers (TELs) that performed off-road mobility tests in the open desert.

"...soon after the first [1974] explosion, grass and shrubs in the area were burnt..." Singh, Business Standard, 1/1/96, pp. 1, 3, + + + -	Since the 1974 test was conducted in the vicinity of established conventional test ranges, it is possible the area was burnt because of live munition firing during conventional exercises that happened after the 1974 nuclear test.	The grass and shrubs in the area may have been burnt by accident. Brush fires are common in arid regions with seasonal vegetation growth.	The grass and shrubs may have been burnt deliberately as part of a post-test experiment. The control burn could have been done in order to determine how abrupt ground motion and radioactive leakage from the 1974 nuclear test affected the regrowth of natural vegetation.	N/A. The Prithvi missile program did not even exist in 1974.

Two brush fires that happened after March 25, 1995	May have been caused by live munition firing in the area during conventional exercises. Alternatively, the fires may have been deliberately set to train troops for operations in a smoke-filled environment.	The fires started along the new security perimeter (see plate 16). The cause may have been two separate accidents that happened during the construction of the new security perimeter.	May have been set to clear vegetation before a planned nuclear test. The cleared ground could then be used as a study area to determine how abrupt ground motion and radioactive leakage affected the regrowth of natural vegetation.	May have been a fire control exercise to train personnel in brush fire containment following a Prithvi field test or launch mishap.

Biggest military exercises every witnessed by locals. Singh, Business Standard, 1/1/96, pp. 1, 3, + + + -	Could have simply been the largest conventional military exercises that have ever been staged in the Pokharan area.	N/A.	Could have been larger than usual because additional personnel and equipment were needed to prepare an underground nuclear test in conjunction with the routine conventional exercises.	Could have been larger than usual because Prithvi missile batteries and support units were added to the regular complement of army regiments.
Road link to/from military base located 4.0 km to the southwest.	Could be the main route for mechanized units to reach the military range for conventional exercises.	N/A.	Could exist so that the nearby mechanized units can provide physical security for the nuclear test site. The site is only 90 km from the border with Pakistan.	Could be used by the nearby mechanized units for participating in coordinated exercises with the Prithvi missile units.

New vehicle tracks to/from Nautala conventional target areas	Could be the tread marks left by artillery units based inside the secured area. Also could be tracks left by mechanized units from the military armor base.	N/A.	Could have been an indirect route for personnel and equipment to get to and from the nuclear test site via the conventional testing grounds. By entering and exiting the conventional ranges, the locals would have interpreted the activity as routine military exercises.	Could be the tread marks left by Prithvi transporter-erector-launchers (TELs) that performed off-road mobility tests in the open desert.

5/18/74 crater with cable line connecting it to the control point 4.8 km southeast of the ground zero	N/A.	N/A.	The crater was created by an underground nuclear explosion. The cable line was oriented perpendicular to the prevailing wind direction. The control point was used for firing the nuclear device, observing the explosion, and monitoring for radioactive release.	N/A.

Surface excavations for burial of nuclear warhead. Senator Cranston, 4/27/81, +	N/A.	N/A.	The Senator's description of surface excavations for burial of a nuclear warhead can only be construed as nuclear test preparations.	N/A.

Village leaders' reports of evacuation plans and new security perimeter. Bedi, Indian Express, 5/5/81, p. 1, + + +	N/A.	N/A.	The official notification of a four-day evacuation plan for nine neighboring villages could have been a safety measure to protect villagers from the earthquake- like ground shock and inadvertent radioactive release from a planned underground nuclear test.	N/A. The Prithvi missile program did not exist in 1981.

Nighttime operation of a machine that sounded like a drill. Bhattacharya, Sunday Magazine, May 9-15, 1982, pp. 12-15. + + +	N/A.	N/A.	The nighttime operation of a machine that sounded like a drill could have been a concerted effort to prepare the ground for underground nuclear testing.	N/A. The Prithvi missile program did not exist in 1982.

In the early 1980s, two holes were completed for future nuclear tests. Sidhu, Jane's Intelligence Review, 4/96, pp. 170-173. +	N/A.	N/A.	The two holes can plausibly be considered the result of the activity that was observed and reported in 1981 and 1982 by Senator Cranston, local villagers, and village leaders.	N/A.

Prithvi-1 mobility and preparation exercises, Sawhney, Asian Age, 12/19/95, pp. 1, 4. + + + +	N/A.	N/A.	N/A.	As described in the article, the activity around the 1974 nuclear test site could have been Prithvi-1 mobility and preparation exercises under field conditions.

Prospective impact points in several military operation areas located > 40 km and < 150 km away.	N/A.	N/A.	N/A.	The March 1991 1:500,000 scale Tactical Pilotage Chart (H-8C) shows five military operation areas that could be used as impact points for Prithvi field tests. From the 1974 nuclear test site, the Prithvi-1 could reach targets in these areas at its minimum range (40 km) and maximum range (150 km).

Multiple perimeter barriers	N/A.	N/A.	At least four layers of security barriers surround the sites in the center of the military range. The reinforcement of these barriers may have been done to secure the sites for the delivery and underground placement of nuclear test devices.	At least four layers of security barriers surround the sites in the center of the military range. The reinforcement of these barriers may have been done to secure the sites for the delivery and temporary deployment of Prithvi-1 test missiles.

Laid out cables. Chari, Hindustan Times, 1/3/96, p. 11. + *	N/A.	N/A.	The cables could have been laid out to fire the nuclear test device and collect data from the nuclear explosion.	The cables could have been laid out to connect the field launch point with the Prithvi transporter-erector-launcher (TEL). Cables are routinely used worldwide for such mobile missile launches.

Identical rectangular structures at sites A and C connected to branches AF and CE which link with line EG and end at point G (see plates 18 and 19)	N/A. The multiple perimeter barriers suggest that the activity inside the secured area was not routine conventional exercises.	N/A.	The linear traces could be cable lines connecting the control point (Point G) with the two shafts that were prepared in the early 1980s (the rectangular structures at sites A and C). As in 1974, the cable link (line EG) is oriented perpendicular to the prevailing winds, which would keep radioactive fallout away from the control point. (See figure 4.)	The linear traces could be road transport links connecting the missile launch point (Point G) to the two buildings for housing the Prithvi missiles and volatile fuel supply (the rectangular structures at sites A and C). The road link (line EG) is 2.1 km long so test launches could be done at a safe distance from the basing areas. It is oriented perpendicular to the prevailing winds, which would keep the toxic exhaust plume away from the basing areas. (See figure 5.)

Sites B and D connected to branches BF and DF which link with line EG and end at point G (see plates 18 and 19)	N/A.	N/A.	Site B is equidistant from the two inferred shaft locations (sites A and C). Thus, it could be a diagnostics station for recording the data that would be transmitted via cable from both explosion sites. Line BG could be a cable link from site B to the control point (Point G).	Site B is equidistant from the two inferred Prithvi storage facilities and is connected to the inferred launch point (Point G). Thus, it could be the missile control point for coordinating the deployment of Prithvi units to the launch point, tracking the missile after launch, and communicating with the impact site.

			Site D is located near the entrance to the central secured area. It could be a support base for nuclear test preparations with a new road link to the control point (Point G). (See figure 4.)	Site D is located near the entrance to the central secured area. It could be a support base for Prithvi field tests with a new road link to the launch point (Point G). (See figure 5.)