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Circuits to add a passive ranging capability to the Interferometric Landmark Tracker (ILT) to form a Passive Range Interferometer Sensor (PRAIS) were built and tested in the laboratory. The laboratory test data were used in a Monte Carlo simulation to demonstrate the performance of the PRAIS Navigation System in a highly eliptical orbit and a synchronous (1 deg inclination) orbit. Navigation accuracies better than 1000 ft and attitude accuracy better than 10 arcsec were indicated by the analyses. (Author), See also Volume 2, AD-A038 489.

This report is Volume II of the three-volume final report on the Self-Contained High Altitude Navigation System (SCHANS) study. Volume I provides a summary description of the system concept, operation, performance, and configuration as well as a statement of application potential, conclusions, and recommendations. This volume describes results of SCHANS contract work by task. Volume III contains circuit level electrical design description of the Interferometric Landmark Tracker (ILT) Receiver and the Pulse Conversion Unit (PCU); it also contains an operational software Computer Program Development Specification., See also Volume 3, AD-A038 490.

A laboratory evaluation of an Interferometric Landmark Tracker (ILT) for an autonomous spacecraft navigation system was conducted. The system processes ILT, inertial reference unit, and star sensor data in a Kalman filter to provide in-space navigation. Sighting accuracy measurements were made over a 120 degree field-of-view on a four-antenna interferometer in an anechoic chamber. Error data from the interferometer measurements were used as inputs to Monte Carlo simulations of the spacecraft and orbital dynamics to determine navigation accuracy for several orbital conditions. Navigation errors and interferometer sighting errors were analyzed in terms of order statistics and cumulative distributions.

The studies conducted under this phase O HANS Study contract evaluated the performance of a Passive Ranging Interferometer Sensor (PRAIS) when used for autonomous navigation of high altitude spacecraft. The autonomous navigation system investigated consisted of the PRAIS, a digital computer and an Attitude Determination System (ADS). Performance of this HANS is five orbits encompassing a range of orbital altitudes from 400 to 150,000 nm was evaluated using covariance analysis for the trade studies and parametric sensitivity analyses. HANS performance in a synchronous equatorial orbit and highly eccentric (Molniya) orbit was demonstrated via a Monte Carlo simulation using order statistics., See also Volume 5 dated Mar 75, AD-A008 486.