EeteS-The EnMAP End-to-End Simulation Tool

The design of future Earth imaging systems, the optimization of fundamental instrument parameters, and the development and evaluation of data pre-processing and scientific-exploitation algorithms require an accurate end-to-end simulation of the entire image generation and processing chain. For this purpose, the end-to-end simulation software EeteS has been developed within the framework of the Environmental Mapping and Analysis Program (EnMAP) mission. This paper presents the EeteS simulation approach and software implementation focusing on calibration and pre-processing. The sequential processing chain of the EnMAP scene simulator consists of four independent parts-the atmospheric, spatial, spectral and radiometric modules. This forward simulator is coupled with a backward simulation branch consisting of calibration modules (non-linearity, dark current and absolute radiometric calibration) and a series of pre-processing modules (radiometric calibration, co-registration, atmospheric correction and orthorectification) forming the complete end-to-end simulation tool. In the result EeteS is capable of simulating EnMAP-like raw image scenes (L0) taking into account a variety of instrumental and environmental configurations. Furthermore, EeteS allows simulations of EnMAP reflectance images carrying out the complete L1 and L2 processing chains. Analysis of the intermediate and final EeteS simulation products has shown the accurate, reliable and consistent performance of the developed modules enabling the system to support technical decision-making processes required for the development of the EnMAP sensor. EeteS has also been used to estimate the SNR characteristics of potential EnMAP products after calibration and pre-processing. Comparing the results to SNR characteristics achieved by the already existing EO-1 Hyperion system has shown a significantly improved SNR which can be expected from future EnMAP data products.