Filter descriptors

The two most critical types of physical information needed about the filters themselves are (1) what are their transmission curves? and (2) does the instrument either regulate or measure their temperature? Filter temperature is important, because filters are somewhat more temperature-sensitive than detectors (see [9], and pp. 105-108 of [10]). In addition, we need to know how many different filter-code fields appear in the data. Bearing all this in mind, here are the descriptors for filters: