On-board computed LST, as a solution, enables efficient reuse of expensive hardware resources, and data can be modified, processed and compressed, reducing the amount of data to be transferred. Additionally, it enables autonomous on-board decisions that can potentially reduce the time between image capture, analysis, and associated action.The trend in the design of hardware modules for small satellites is to use hardware devices certified for space operation, small in size and low in cost, but with flexibility and high computing power. Available spacecraft processors are power-intensive, expensive, require additional interface cards, and are limited in computational capabilities. FPGA circuits have been certified by international remote sensing agencies, they also offer high flexibility, exact results with compact size and much shorter design cycle, which makes the reconfigurable system attractive for on-board data processing. As a solution, the radiation-hardened Virtex-4QV type FPGA (SRAM, 90 nm) is suitable as a solution due to its ability to operate in a high radiation environment, especially for space remote sensing missions.