<title>Design and analysis of a small bispectral infrared push broom scanner for hot spot recognition</title>

Abstract

A small bispectral infrared detection (BIRD) push broom scanner for a small satellite emission is described, which is dedicated to the detection and analysis of high temperature events (HTE). Current operating and planned satellite sensors are not designed for high temperature event observation and therefore show some serious drawbacks such as saturation of the IR channels for target temperatures higher than 50 degrees Celsius, low spatial resolution in case of daily coverage, low coverage of spatially high resolving systems, or not adequate IR channels. The BIRD instrumentation is a first attempt to overcome these disadvantages. For this purpose two infrared line scanners (3.4 - 4.2 micrometer and 8.5 - 9.3 micrometer) are combined with a wide angle stereo scanner (WAOSS) in the visible. Because of the limited resources of a small satellite the design of all instruments is based on the usage of staring focal plane arrays. To observe HTE directly the covered sounding area should be as large as possible whereas at first glance the ground resolution of the sensor should be in order of some 10 m. These demands are in contradiction with the number of the infrared detector array elements currently available. For this reason methods of subpixel target detection and analysis have to be used. According to this concept a combination of the data from at least to radiometric high sensitive infrared sensor channels is used to compensate the lack of high ground resolution. Adding to the infrared cameras a suitable CCD-line scanner for a pre-classification with a higher ground resolution, a marked improvement can be achieved.