Accession Number : AD0704355

Title :   ALL-WEATHER LOW-LEVEL NAVIGATION.

Descriptive Note : Annual rept. no. 2, Oct 68-Oct 69.

Corporate Author : OHIO UNIV ATHENS DEPT OF ELECTRICAL ENGINEERING

Report Date : MAR 1970

Pagination or Media Count : 161

Abstract : Progress on the research and development leading to an All-Weather, Low-Level Navigation System is reported and significant findings are given. The major efforts have been in the areas of receiver design, investigation of time references, flight simulation, computer design and diagnostics. Previous work led to the selection of a range-range geometry for position fixing and one-way, low-frequency ranging for implementation. Research on the use of accurate time standards to provide the reference for calculating range has indicated that drift will impose a limitation in positional accuracy which presently is 200 feet for one hour of flight with crystals and 50 feet with rubidium standards. A discussion of a phase measurement technique using a maximum likelihood estimator as applied to the low-frequency one-way ranging is presented and plans are given for implementation. A simulation is underway using a hybrid computing facility to ascertain the parameter values needed for the design of a special purpose airborne computer. This will generate command information for the pilot; and will be based on received positional information compared to prestored route information. The progress of this work is described. Special topics are reported which have been investigated. These include a doppler difference navigation scheme, propagation effects of electromagnetic energy and display requirements.

Descriptors :   *ALL WEATHER AVIATION, *RADAR NAVIGATION, INSTRUMENT FLIGHT, TERRAIN AVOIDANCE, NAVIGATION COMPUTERS, LOW ALTITUDE, HYPERBOLIC NAVIGATION, DOPPLER NAVIGATION, DISTANCE MEASURING EQUIPMENT, DISPLAY SYSTEMS.

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE