Interferometer Signal Processing Subsystem
The RUAG Space (RSA) Interferometer Signal Processing Subsystem provides the signal processing chain of an infrared interferometer used for atmospheric sounding. The equipment contains 5 dual processor digital signal processor boards constituting the hardware platform for the digital signal processing algorithms, two (nominal and redundant) power converter boards and a cross-coupling board for power distribution. These boards are hosted in a box together with boards for the control computer and the input and output interface, forming the complete data processing subsystem.
The processor boards are equipped with two ASICs (also developed by RSA), which augment the functionality of the boards with interfaces and support functions.
In addition to the hardware development, RSA also provides the signal processing software.
The space qualified dual processor digital signal processor (DSP) boards developed by RSA constitute the core processing unit of an infrared interferometer. The DSP boards are based on the TSC21020F, a radiation hardened version of the Analog Devices 32-bit floating point DSP ADSP21020. The development of a dual processor board is challenging from both an electrical engineering and from a layout point of view, due to the limited amount of available board space and the need to dissipate the heat generated by the high speed digital logic.
The demanding implementation of the software requires a detailed insight and understanding of on the one hand the underlying signal processing aspects and on the other hand the features of the used digital signal processor in order to fulfil the accuracy requirements and timing constraints with a minimum of required hardware.
The product has been developed for the Infrared Atmospheric Sounding Interferometer (IASI) Data Processing Sub-System (DPS), which is part of the IASI instrument on board of the METOP satellite.