Tuz Gölü: New Absolute Radiometric Calibration Test Site

Calibration, absolute radiometric calibration in specific, is an important process for continuity and reliability of optical satellite data, since it puts the data on a standard scale and makes it compatible and comparable with the data acquired from different sensors. Therefore, the importance of performing a calibration campaign increased significantly. Being aware of this significance, TUBITAK UZAY (Space Technologies Research Institute, The Scientific and Technological Research Council of Turkey), by taking advantage of having such a suitable site in the country, decided to establish a new absolute radiometric calibration test site on Tuz Gölü (Salt Lake) for the calibration and validation requirements of cal/val community in general and of the country, specifically. In order to evaluate the usability of the site and determine the most usable area, we first compiled a list of properties that a calibration/validation test site should have. We have seen that Tuz Gölü fulfils most of those requirements. Later, we performed homogeneity analysis using Getis Statistics on MODIS satellite images of July and August 2004-2007. As a result of analysis, we obtained approximate usable area to be 324.026 km. We also observed that, the longer duration the region is covered with water, the more homogeneous it is. The site will be visited annually and further analysis and field studies will be conducted. The test site is considered to be useful to scientists all over the world. * Corresponding author.