Satellites that measure the chemical composition of the atmosphere are becoming more accurate and numerous, providing a unique opportunity to independently monitor emissions for large geographical regions in a consistent way. This report elaborates the development of a software tool which is able to process satellite observation data and estimate NOx emissions from it for a pre-defined area. The tool is fully operational for processing satellite observations from the TROPOspheric ⁠Monitoring⁠ Instrument (TROPOMI) and the Ozone Monitoring Instrument (OMI). The tool is modular in design with the capability in mind to digest satellite data from various satellites and for pollutants. It is furthermore designed to be relatively simple and operates without a dependence on complicated and computationally demanding atmospheric models. The methods for satellite based emission estimation can complement data from emission inventories by incorporating independent measurement techniques into the reporting scheme. This would help to identify room for improvement in the compilation of inventories as well as boost the transparency and confidence in the reported data.