In-orbit VNIR sensor quality validation

The Institute of Optical Sensor Systems (OS) at the Robotics and Mechatronics Center of the German Aerospace Center (DLR) has more than 40 years of experience in high-resolution imaging and imaging technology. This paper presents the current status of the institute’s work on next-generation CMOS-TDI detector development. Together with the partners IHP (Leibniz Institute for High Performance Microelectronics), IMS (Fraunhofer Institute for Microelectronic Circuits and Systems), and JOP (Jena-Optronik GmbH), a new test detector was designed consisting of an embedded charge-coupled device (eCCD) and a readout integrated circuit (ROIC), combined as a silicon-bonded design. This approach enables operation at a line rate up to 150 kHz and a full well capacity above 150 ke-, thus making it very promising for high-spatial-resolution imaging systems. An FPGA-based engineering model environment with high design flexibility distributes all eCCD clocking and ROIC control signals. The unidirectional eCCD design is optimized for electrical charge injection tests and is used to verify in-orbit initialization approaches, including eCCD signal reconstruction. The paper will outline this procedure. Due to the accessible detector building blocks, this setup is ideally suited for future evaluation and verification of accumulative radiation effects on the eCCD and ROIC structures and determining possible corrective actions to contain overall radiation-related performance degradation over the mission lifetime. The evaluated method is intended to estimate the sensor’s behavior under space environmental conditions during the entire mission by introducing a detector initialization phase.