Very high resolution radiometer /VHRR/

Discussion of the design and performance of the very high resolution radiometer (VHRR) representing the first of a second-generation of infrared scanning radiometers of high performance. Following a description of the optical, signal-electronics, sync-generator, scan-drive, cooler, and contamination-protection design, it is pointed out that the two VHRRs presently operating have logged a total of 15,500 hrs of continuous successful operation since launch. The cooler operation has been particularly noteworthy. The cold plate heater power, required to maintain the detectors at 105 K, has undergone in almost a year's operation so small a degradation as to indicate a VHRR cooler lifetime exceeding the instrument design lifetime of one year by a large margin. High resolution, low noise, and jitter-free pictures are shown to have been derived from these instruments.