Image Chain Simulation for Earth Observation Satellites

We present a general-purpose end-to-end image chain simulation (ICS) that enables to assess the image quality of a satellite imager for Earth observations. The image chain consists of four main components: radiometry, atmosphere, optics, and detector. In particular, ICS first computes the input radiance from the reflectance values of a high-resolution input, and then calculates the image radiance by using the optical transfer function (OTF) of the overall system. This OTF contains all the distortion effects due to atmosphere, optics, and detector. Finally, the signal on the detector, including the noise term, is computed and converted to digital counts. To evaluate the overall image quality, metrics such as peak signal-to-noise ratio and minimum resolvable contrast are used. To illustrate the utility and versatility of the developed ICS, several analyses are also performed that demonstrate the system performance of a generic satellite imagery. Our development provides a unified framework for the ICS developers of spaceborne Earth-observing systems. Such a complete end-to-end ICS is crucial for the effective development of an Earth observation satellite, especially in the design and test phases.