SNR Evaluation of the RapidEye Space-borne Cameras

Abstract

Summary: After launch and continuous radiation exposure, space-borne cameras are constantly changing. Therefore permanent technical specification and evaluation of the sensor in space plays an important role in the remote sensing community. There are a variety of evaluation criteria, which are all based on the essential camera parameters – the spatial resolution, point spread function (PSF) and noise. Noise estimation is a challenging task for characterization of remote sensing systems in space. The in-flight measurement of noise will often be done with artificial test sites. If these test sites are not suffi-ciently available, homogeneous image regions (desert, snow, water surfaces) are often used. The al-bedo of these objects, however, lies normally outside the specified albedo range of remote sensing systems focused on the Earth's surface. The only possibility to determine the noise after the satellite launch within the normal operational albedo range is to use normal surface objects within the oper-ationally acquired imagery. As these objects have to be homogeneous, one needs methods that can detect the smallest homogeneous areas in the image to evaluate noise. In this paper an approach for determining the signal to noise ratio (SNR) with data from natural tar-gets is presented. In experiments, the results demonstrate that the described method performs well and results are comparable to the standard methods used to determine SNR.