Tutorial: How to geolocate a prison in Tibet with Google Earth

Audio transcription for accessibility.

Starting a project to map out prison locations in the Tibet Autonomous Region (TAR) is quite a daunting task. This article will showcase a few of the methods and sources the Tibet Research Project utilised to identify many prisons and detention centres. In this case, we will be looking at finding and identifying a prison from a prisoner report in Google Earth Pro.

The Tibet Autonomous Region (TAR) has a population of 3.5 million spread out over a land area comprising more than 1.228 million km2. In the literal sense, there is much ground to cover. However, several open-source methods, tools, and sources will help you in your research.

While I enjoy starting at Tibet from above, for some, relying on scrolling endlessly through the Tibetan terrain, while necessary at times, can become rather tiresome. Thankfully, previous work by human rights organisations, such as Amnesty and Human Rights Watch, and Tibet-focused organisations, like SaveTibet, have routinely reported on detained political prisoners in Tibet. In addition, government institutions such as the Congressional Executive Commission on China (CECC) have also published annual prisoner reports. We can use these sources to help identify and verify prison locations.  

In most cases, these reports will include the county or city the person has been detained in, and sometimes, if you are lucky, there will be a photo attached showing the prison. In the case example below, the report includes a name and a picture, and we will use Google Earth Pro historical images to identify it. Google Earth Pro is a free-to-download app available on all major operating systems. Historical imagery is a tool within the app that allows one to look at dated satellite imagery; the amount of historical imagery varies from place to place.

Case Study: finding Nyalam Prison

This article from SaveTibet, written in 2003, describes the detention of several prisoners trying to escape Tibet into Nepal. These prisoners are then detained at a ‘Nyalam Prison’ located ‘near the Tibet-Nepal border’ before being transferred to another prison inland.

Image alleged to be of Nyalam Prison

Straight away, we can see that this is most likely a detention centre, though a particularly small one, compared to other centres identified in the Tibet Research Project. The primary analysis shows the facility has one watchtower and two small buildings used for holding prisoners (see image below). A quick google of ‘Nyalam’ shows it is a town and county in the south of Tibet near the Tibet-Nepal border.  This prison is most likely the Nyalam County Jail.

In this case, it is relatively easy to find Nyalam in Google Earth Pro, plot the name in, and we can now have a look around. However, sometimes it is not that simple. In many incidents, there exists a plethora of name-variants and alternatives for a given location. In those cases, cross-referencing previous work, like this report by Human Rights Watch (which lists all Tibetan counties in Romanised Tibetan and Mandarin, as well as in Mandarin itself) in order to find the exact name of a county or area. Such sources are also useful when later attempting to verify a known location. In the most recent imagery (2017) of Nyalam Town, I cannot seem to find anything that matches the primary analysis, but we do find a larger prison, located here: 28° 9’41.64″N 85°58’46.92″E. In the image below, the historical imagery tool button and date of imagery is marked in the top left, and the location of the prison from 2017 imagery is marked in the middle:

We know the prison’s source-image is from 2003 at the latest, and the prison has likely been subject to change in the 18 years since. Luckily, Google Earth Pro has historical images of this location dating back to 2005. The image below is from December 2005:

Since the 2005 satellite imagery quality is poor, making it hard to determine whether we have the correct location, we can go back to our original image and find some points of interest (POI) for further analysis. It is essential to focus on aspects easily identifiable from above, such as nearby houses, the landscape, and the prison layout. In the analysis below, I have noted five POIs: a) building in the background, b) closer building with a pointed triangular rooftop, c) a road or plateau in the mountain/hill side d) a building with a flat and dark rooftop e) a particular zigzag wall-structure with a gap where there appears to be a gate.

Upon closer inspection of the location in question, though blurry, we can identify the same POIs in the 12/2005 satellite imagery.

In conclusion, we have found the prison referred to as ‘Nyalam Prison’ in our source and can further note that the prison has been subject to several changes and upgrades since 2003. The historical imagery on Google Earth Pro is a useful tool the Tibet Research Project has used to identify and verify prisons across the Tibetan landscape, often combined with other resources and tools. In a future article, we will look at how the Tibet Research Project verified several locations using open-source information and techniques.