The development of a data acquisition system for a high resolution infrared imager

A real-time data acquisition system has been developed for a Mitsubishi Electronics Corporation IR-M500 imager. The imager contains a 512 x 512 infrared focal plane array detector that produces 10-bit digital pixel data at 9.2 megapixels per second. The data acquisition system consists of a digital interface unit, time code translator/generator, personal computer, software, and a non-volatile data storage system. The digital interface unit is used to insert a time code into the imager's digital output data stream before each image field. Also, it formats the image/time data stream to allow for the use of an Adtek, Inc. direct memory access (DMA) board. The DMA board is used to transfer the digital interface unit's output data into the system memory of a 90 megahertz Pentium-based PC. A program written in the C programming language was developed to setup the DMA board for 32-bit input read operation. Also, the program transfers the real-time data from PC system memory over a PCI local bus/SCSI adapter to a 10 gigabyte hard drive array storage system. The data acquisition system is operational and has already been applied on several AEDC infrared measurement programs. Before this work, data reduction was performed off-line using a frame grabber with an 8-bit dynamic range. The image data collected by the new system is reduced to engineering units in near real-time. The dynamic range of the imager data has been increased by a factor of four while at the same time data reduction time has been decreased.