High-Resolution Satellite Imagery and the Conflict in South Ossetia
AAAS conducted a damage assessment of 24 village areas in the region of Tskhinvali, Georgia, to corroborate reports by Amnesty International of violence against civilians and property destruction during the Georgia-Russia conflict of August 2008. This report documents the scope and extent of damage between August 10 and August 19, 2008. Imagery analysis demonstrates initial concentrated damage to the city of Tskhinvali and small amounts of damage to outlying areas that had occurred by August 10. By August 19, a much broader range of destruction occurred in the village areas surrounding Tskhinvali (see Appendix One). Other significant signs of military actions were also shown to have occurred in the region, including many obvious craters from munitions and tracks from the presumed movement of military vehicles, which resulted in clear damage to the vegetated areas throughout the region (Figure 7).
A. Image Acquisition
B. Image Analysis
A. Locations sustaining no damage
B. Locations exhibiting damage on August 10 and August 19
C. Locations exhibiting damage on August 19 only
D. Full damage assessment not possible
E. Damage to unpopulated areas and evidence of conflict
V. Further Resources
Appendix One: Overview of Damage to Tskhinvali Region by Date
In August 2008, AAAS staff began a review of satellite imagery of the Tskhinvali region of South Ossetia. Amnesty International (AI) contacted AAAS over concerns in regard to hostilities between Georgia and Russia, which began approximately 7-8 August 2008. Specifically, AI was gathering field reports from local informants of violence occurring in multiple cities and smaller villages throughout Georgia. These reports indicated destruction and violence toward civilians in many areas, particularly near Tskhinvali, a city in South Ossetia close to the Georgia-Russia border.
Based on AI witness reports from the field, an initial set of target regions for satellite imagery acquisition was constructed. Significant challenges arose in the early stages of this project. Satellites operated by major commercial vendors (GeoEye, DigitalGlobe, and ImageSat International) were fully booked, preventing the tasking of a new image by AAAS for the duration of this conflict. Therefore, AAAS was forced to rely upon imagery requested by other entities to meet the needs of the project. Fortunately, it was possible to acquire imagery of the region surrounding Tskhinvali, one of the major sites of damage upon areas of civilian infrastructure, with a time scale concurrent to the conflict in the region. Specifically, AAAS acquired satellite imagery of the region for the dates of August 10 and August 19, 2008 to establish whether satellite imagery analysis supported AI’s witness reports.
Correlating these images with on-the-ground reporting in a timely fashion remains a difficult task. However, reports from AI named a number of villages in the Tskhinvali region that were possibly the targets of attack. Based on this information, AI requested specific types of imagery analysis to demonstrate the scope of damage to civilian infrastructure in identified communities.
AAAS conducted imagery analysis of close to 1,000 square kilometers (km2) of the region surrounding the city of Tskhinvali. This analysis covers the region in two different time periods during the Georgia-Russia conflict: August 10, just two days after events began to unfold, and August 19, by which time most fighting had ceased. The imagery acquired on these dates was used to construct a timeline of damage to Tskhinvali and its surrounding villages. Analysis of these and other satellite images is the focus of this report, and the specific region covered by this analysis can be seen in Figure 1 below. Additional analysis of this region was conducted by the UN Institute for Training and Research (UNITAR) Operational Satellite Applications Programme (UNOSAT)1 , with whom AAAS cooperates. The analysis provided in this report is intended to complement UNOSAT’s work, which largely covers the city of Tskhinvali and numerous villages to the north of the city as they appeared on August 19. This analysis covers regions to the east and south of Tskhinvali.
Figure One: Overview of damage assessment area
Satellite image analysis was conducted by AAAS and undertaken at the request of Amnesty International (AI) in order to document the destruction to civilian areas, and its timing, during the conflict between Russia and Georgia over the regions of South Ossetia and Abkhazia. AI provided AAAS with the names of several villages throughout Tskhinvali region which on-the-ground informants indicated had been attacked in the course of the conflict. AAAS used these villages and public news sources to identify possible satellite imagery acquisitions. Unfortunately, no commercial satellites were available to AAAS at the time of the conflict, and thus AAAS could not actively task image acquisitions in the region. Ordering satellite imagery does not occur on a first-come, first-served basis. Rather, commercial considerations can largely dictate where and when imagery is acquired. As such, satellite tasking priority generally falls to the United States Government (USG), which has the ability to purchase as much satellite time as it wants and can legally have its orders to US companies take priority above those of other customers. After the USG, priority is given to commercial customers with similarly large requests. Lowest priority is given to small-budget requests. Therefore, when AAAS requested a new acquisition of the Tskhinvali region, there was no satellite time available for purchase. Despite the inability to acquire new imagery of the region, AAAS utilized a number of different high- resolution imagery sources, each with spatial resolution of one meter or better. All of the images used were originally requested by other organizations. A full list of image sources is found in Table 1 below.
Table One: Imagery Information
|Satellite/Source||Image Date||Acquisition Time (UTC)||Image ID|
Based on imagery collected by commercial satellites at the request of other parties, AAAS determined that the city of Tskhinvali and its surrounding villages were the only viable targets for image analysis. As a result, AAAS acquired several images identified from available satellite imagery as likely to provide insight into the conflict. Other additional images, pre-dating the conflict, were also examined.
One source was the Ikonos satellite, operated by the GeoEye2 corporation. Ikonos is a multispectral (color) satellite with one meter panchromatic (black and white) resolution that has been in operation since 2000. The other satellites utilized were WorldView and QuickBird, operated by DigitalGlobe3 , which have panchromatic 60 centimeter spatial resolution and 50 centimeter4 resolution, respectively. QuickBird became operational in 2002, while WorldView began delivering imagery in late 2007. QuickBird also has multispectral capabilities, while WorldView is solely panchromatic. The last sensor used was EROS-B, operated by ImageSat International5 and launched in 2006, which has a panchromatic sensor with 70 centimeter resolution.
Of special note, the general public cannot request WorldView to acquire images of specific locations, but the public can purchase such images if they are in the DigitalGlobe archives. Only the US Government can direct WorldView to acquire new imagery. While QuickBird and WorldView provide the greatest level of detail and are thus preferred for new image acquisitions, Ikonos was the only sensor that had acquired imagery of the South Ossetia region prior to August 19, and therefore was used as the main image in this analysis.
AAAS employed the software packages ERDAS Imagine and ArcView for processing satellite imagery and creating geo-referenced damage assessments. The sources of acquired imagery and other data included:6
- Google Earth base layers were used, where possible, for comparison to the state of the region prior to the conflict;
- QuickBird high-resolution imagery purchased in areas lacking a high-resolution base layer on Google Earth;
- an IKONOS image from August 10, 2008;
- a WorldView image from August 19, 2008;
- an EROS-B image from August 19, 2008;
- placenames compiled from the US National Geospatial Intelligence Agency;7, 8
- national and administrative unit borders compiled from Digital Chart of the World9
These findings are discussed in depth in the upcoming pages, and highlight the types of damage sustained to different areas of the Tskhinvali region. Summary findings are found in Table 1 and a map indicating overall damage is located in Appendix One.10
Reference will be made regarding damage to various civilian structures and infrastructure in this report. This damage is a specific type of damage to structures and does not encompass all possible damage types. Analysis of satellite imagery constrains identification of damage to incidents which can be observed from above, and does not provide insight to any damage that may have been sustained to other portions of structures, such as sides of buildings. Damage assessment is conducted in geospatial software packages, whereby each image is compared to an image from an earlier date to determine if damage has occurred to each individual structure observed. Specifically, the two images are viewed alongside one another to quantify changes to structures through visual analysis.
|Figure 2A: Before image||Figure 2B: After image|
|Image A (07/02/05) is used as a baseline for damage assessment. The blue circle shows one building, lacking a roof. This building would appear damaged in Image B if no “before” comparison had been done, as its lack of a roof could be construed as damage in later images. Image B (08/10/08) is compared to Image A to identify any damages occurring between the image dates, keeping in mind there is one building in Image A that could appear to be damaged in Image B (blue circle).|
|Figure 2C: Damage assessment|
|Image C (08/19/08) is compared to Image B to identify changes occurring between the two image dates. Changes are identified with red circles throughout Image C. Damage from Image B and the building from Image A are shown to highlight that damage is counted only once, regardless of the number of image dates used.|
The results of the image analysis, with side-by-side images, are presented below. Table 2 below also summarizes the results of the analysis.
Table 2: Results of Satellite Imagery-Based Damage Assessment for Tskhinvali Region
|Village||Damaged 8/10/2008||Damage Count for 8/10/2008||Damaged 8/19/2008||New Damage Count for 8/19/2008||Total Damage|
|Total by Date||—-||202||—-||424||626|
|Table 1 provides an overview of the damage observed for the 24 populated places in the AAAS imagery analysis. After locating a place of interest, reading the table across indicates on which days that location exhibited damage (if any) as well as the damage observed for each image date. The far right column (Total Damage) sums the total damage at each location, and the bottom row (Total by Date) gives the complete tally of observed damage for each date. There were 202 damaged structures observed in the region on August 10, and 424 damaged structures on August 19, for a total damage count of 626.|
There were a number of village areas in the region which did not sustain any quantifiable damage, according to the satellite imagery analysis. There were a total of nine villages in this category: Meret’i, Kordi, Shida Kartli, Tergvisi, Khviti, Megvrekrsi, Nikozi, and Dgvoisi. As can be seen in Figure 1, these villages are largely in the far eastern and southern areas.
Many of the areas had observable damage on both August 10 and 19. Notably, the majority of damage was sustained prior to August 19, but after August 10. These include the areas of: Argvitsi, Eredvi, Prisi, Ergneti, Dits’i, Zemo-Nikozi, and Zemo-Khviti (refer to Table 1 for specific damage assessments). Figures 3 (A-C) and 4 (A-C) highlight damage to the Eredvi-Berula-Argvitsi corridor and the village of Ergneti.
|Figure 3A: August 10, 2008||Figure 3B: August 19, 2008|
|©2008 GeoEye||©2008 DigitalGlobe|
Damage to the Eredvi-Berula-Argvitsi Region. The orange circle highlights the nine structures in the main village area of the region destroyed by August 10. Figure 3B shows August 10 destruction (orange circle) and August 19 damage (red markers). By August 19, 147 structures were either damaged or destroyed.
|Figure 3C: Subset of damage to the
Subset of August 19, 2008 image. Red circles indicate damage typical to the region. Damage is apparent, and it can be seen that the roofs of buildings are no longer present, exposing interior walls. Lat: 42.241° Long: 44.03°.
|Figure 4A: August 10, 2008||Figure 4B: August 19, 2008|
|©2008 GeoEye||©2008 ImageSat International|
Damage to Ergneti. One damaged structure was identified for Ergneti on August 10. Another 52 damaged structures were observed in the August 19 image.
|Figure 4C: Subset of Ergneti|
|©2008 ImageSat International|
Damage to Ergneti. Red circles highlight damaged structures in Ergneti on August 19. Lat: 42.206° Long: 43.988°.
Unlike the areas described above, which sustained major damage between August 10 and August 19, the city of Tskhinvali sustained the majority of its damage (182 structures) on or before August 10. Only a small amount of damage (4 structures) appears to have occurred after this date. Figures 5 (A-C) illustrate the extent and spatial distribution of the destruction.
|Figure 5A: Tskhinvali on August 10 with
damage overlay from August 10 and 19
Orange dots represent damage present on August 10, red dots on August 19. Dots in the far north and southeast are included in assessments for Tamarsheni and Ergneti, respectively. Note that the majority of damage to Tskhinvali occurred prior to or on August 10, with 182 structures damaged, while only 4 additional damaged structures have been identified for the city on August 19.
|Figure 5B: Subset of August 10 Tskhinvali image|
Subset of August 10 image of Tskhinvali city, highlighting damage to multiple structures, covering an area of approximately 0.6 km2. Lat: 42.235° Long: 43.966°.
|Figure 5Ci: August 10, 2008||Figure 5Cii: August 19, 2008|
|©2008 GeoEye||©2008 DigitalGlobe|
Illustration of damage occurring to the city of Tskhinvali prior to August 19, 2008, but occurring after August 10. The building within the red circle is intact in the first image and visibly damaged, with its roof destroyed, in the second image. Lat: 42.221° Long: 43.966°.
Berula was a village which sustained major damage in the nine days between the two image dates (Figure 3). There was no observed damage to this location on August 10, and 70 damaged or destroyed structures on August 19. Additionally, the villages of Brotsleti and Tirdzinisi were observed to be damaged only on August 19, with damaged structures numbering 5 and 7 structures, respectively.
Tamarsheni (Figure 6 A-C) is the village area which exhibited the most substantial damage on August 19. Tamarsheni exhibited no damage on August 10 and a damage count of 152 structures on August 19. This area was also analyzed by UNOSAT using an image from August 19, which confirmed nearly complete destruction of Tamarsheni.11
|Figure 6A: Tamarsheni on August 10||Figure 6B: Tamarsheni on August 19|
|©2008 GeoEye||©2008 ImageSat International|
In the August 10 image of Tamarsheni, no damage is visible. By August 19, 152 total structures had sustained damage, as indicated by the red dots.
|Figure 6C: Subset of Tamarsheni|
|©2008 ImageSat International|
Subset of image covering Tamarsheni on August 19. Widespread damage is visible to nearly all the buildings in the area, indicated by their lack of rooftops. Lat: 42.247° Long: 43.963°.
In addition to the areas described above, there were areas that were partially obscured by clouds and/or cut- off from the image bounds, resulting in incomplete damage analysis. These three locations were Tkviavi, Shua-Khelchua, and Karbi. Partial damage assessment results for these locations can be found in Table 1.
Although a large amount of the destruction observed in the August 10 and 19 images takes the form of structural damage, there are also numerous other indications of conflict visible throughout the region. In many areas, track marks from large vehicles can be seen crossing agricultural fields (Figure 7 A-B). Numerous craters dot the region, with 455 visible between the two image dates (Figure 7C). Lastly, significant amounts of military hardware, including vehicles, helicopters, and tents, are found throughout the imagery.
|Figure 7A: Fields near Tskhinvali on August 10||Figure 7B: Fields near Tskhinvali on August 19|
|©2008 GeoEye||©2008 ImageSat International|
Portions of the August 10 image, such as the one above, show a lack of military presence in many areas on or before that date. Tracks from large vehicles can be seen throughout this image, as well as a large number of disturbed areas on the ground, measuring approximately 3-4 meters in diameter, which are possibly craters from munitions. Note that while the August 10 image is a multi-spectral image (full color) and the August 19 image is panchromatic (black and white), the images are comparable for analysis purposes. Lat: 43.994° Long: 42.226°.
|Figure 7C: Signs of conflict near Ergneti on August 10, 2008|
This image subset covering the village of Ergneti highlights further signs of conflict occurring on August 10. The red circles indicate possible craters from munitions, which occur in a roughly linear pattern toward the village. Each circular area has a diameter of approximately 30-40 meters. Lat:40.039° Long: 42.244°.
AAAS conducted a damage assessment for 24 village areas in the region of Tskhinvali, Georgia, to corroborate field reporting provided by Amnesty International. This imagery assessment sought to ascertain the damage sustained by the region and its infrastructure as a result of the conflict between Russia and Georgia. The report documents the scope and extent of damage between August 10 and August 19, 2008. Imagery analysis demonstrates initial concentrated damage to the city of Tskhinvali and small amounts of damage to outlying areas that had occurred by August 10. By August 19, a much broader range of destruction occurred in the village areas surrounding Tskhinvali (see Appendix One). Other significant signs of military actions were also shown to have occurred in the region, including many obvious craters from munitions and tracks from the presumed movement of military vehicles, which resulted in clear damage to the vegetated areas throughout the region (Figure 7).
- Google Earth Layer
- The Independent International Fact-Finding Mission on the Conflict in Georgia, commissioned by the Council of the European Union, released these findings concerning the 2008 fighting. Included in the report are references to the AAAS analysis of South Ossetia (See Volume II, page 368).
- Imagery analysis from this report is also included in the International Crisis Group’s policy briefing, Georgia-Russia: Still Insecure and Dangerous (See page 3 and Appendix D).
|Appendix One: Overview of damage to Tskhinvali region by date|
4. While WorldView has 40 centimeter capability, it is degraded to 50 centimeter resolution for non-US Government (USG) client as required by US law.
6. Detailed information concerning satellite imagery is included in Section III.
7. National Geospatial Intelligence Agency: http://www.nga.mil
8. A note on village names: some villages had multiple names attached; one has been chosen to be represented in the maps for sake of clarity. Best attempts have been made to associate damaged areas with village names. However, available datasets are never completely accurate, and some liberties were taken with associations between damaged locations and nearby village names. If any questions arise, locating a village on the map is always the more accurate option.
9. University of Pennsylvania Digital Chart of the World Server: http://www.maproom.psu.edu/dcw/
10. In addition, all imagery and analysis is available for viewing using GoogleEarth by accessing: http://www.aaas.org/international/geotech/ge/georgia.kml
11. This report may be accessed from the UNOSAT website, http://www.unitar.org/unosat/