RADIOMETRIC INSTRUMENTATION TECHNIQUE STUDY.
Abstract:
The report considers the use of microwave radiometric equipment to determine the orientation of the line passing through the center of the moon, the earth, and the sun when the observation position is located in cislunar space. The errors in such determination are examined as a function of receiverantenna parameters, operating wave length, radial range of the receiver from the source body, and the thermal emission variations of the source. Because emphasis is on general applicability of radiometric instrumentation, servo errors are excluded from analysis. Considered are the electronic tracking errors, due to finite receiver threshold sensitivity, and the error due to equivalent emission center shift, caused by source emission variations. The latter error, in the case of moon tracking, is determined as a function of lunar phase and, in the case of earth tracking, is determined as a function of latitudinal, seasonal, and diurnal emission variations as well as emission variations due to solar activity. Also investigated were the transitional problems associated with wide variations of radial range from the source and the possibility of obtaining range information by a passive equipment. Author