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Spatial frequency response of an optical heterodyne receiverThe analysis of a passive heterodyne receiver with respect to its imaging performance (transfer function) and its heterodyne efficiency shows departures from the results which are obtained in strictly coherent or incoherent imaging systems. The cascading property of modulation transfer function analysis must be carefully applied, since the coherent transfer function of the optical receiver and that due to the local oscillator-detector combination are not separable but are related by the convolution of their products. Application of these results to a spacelab-type optical heterodyne receiver shows that resolutions of the order of 1.5 to 2.0 km are possible for worst-case type orbital scenarios. In addition to an analysis of the derogatory effects of sampling (aliasing) a comparison of obscured-type receivers (e.g., Cassegrains) with unobscured receivers shows that both resolution and efficiency are severly degraded in an obscured-type receiver and, consequently, should not be used for passive heterodyne detection schemes.
Document ID
Document Type
Technical Publication (TP)
Robinson, D. M. (NASA Langley Research Center Hampton, VA, United States)
Fales, C. L. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 4, 2013
Publication Date
December 1, 1980
Subject Category
Report/Patent Number
Funding Number(s)
PROJECT: RTOP 147-40-01-01
Distribution Limits
Work of the US Gov. Public Use Permitted.

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NameType 19810005228.pdf STI