An FPGA-based Focal Plane Array interface for the Panchromatic Fourier Transform Spectrometer

Panchromatic Fourier Transform Spectrometer (PanFTS) is an Instrument Incubator Program (IIP) funded development to build and demonstrate a single instrument capable of meeting or exceeding the requirements of the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission. The PanFTS design provides atmospheric measurement capabilities in the IR and UV-Vis by using imaging FTS to provide full spatial coverage. For the atmospheric composition, the instrument includes up to four Focal Plane Arrays (FPA) of 256×256 pixels that are read at a frame rate of 8 kHz. We have developed an interface that records pixel data from commercially available IR FPAs that are capable of the required frame rate at a lower spatial coverage, and of the required spatial coverage at a lower frame rate. This interface uses high speed ADCs from Analog Devices and the Xilinx Virtex-5FXT FPGA (V5FXT). The IR signal chain electronics and the demonstration of the FPA data capture are highlighted in this paper. Achieving the full spatial coverage will require FPAs with in-pixel ADCs using delta-sigma conversion. JPL has developed a read-out integrated circuit (ROIC) utilizing this technique and has bump-bonded it to the detector portion of an FPA. The data acquisition and processing system for handling delta-sigma conversion from this new imager is the current work of the PanFTS IIP.