HF (high-frequency) absolute time of arrival sensing. Interim report, September 1981-May 1985

Technical Report · Sat Feb 01 00:00:00 EST 1986

OSTI ID:5383509

Rose, R B

In late 1980 questions arose concerning whether the ionosphere was sufficiently stable to allow precisely measured time of arrival of skywave signals to be used for geolocation in the high-frequency (HF) band between 2 and 32 MHz. The chief limitation in the accuracy of this type of system is the amount of uncertainty in the ionospheric-height estimation and its temporal stability. Traditional ionospheric research resources did not address the issue in sufficient detail and time resolution to be of any assistance. In order to understand the exact nature of the ionospheric uncertainties and to quantify their extent, experimentation was proposed to sense the variation in the refraction height of the ionosphere as it relates to the time of arrival of the HF signal. The objective of this work was to determine the range of environmentally induced errors in a skywave Time Difference of Arrival (TDOA) measurement, thereby bounding the ultimate geolocation accuracy one could expect from this technique. The first experimental measurement system started operation in early 1981. This effort involved establishing a continuous absolute Time of Arrival (TOA) experiment over the one-hop midlatitude path between San Diego, California and Fort Collins, Colorado. The system is fully digital and stabilized with a cesium-beam standard. This work was supplemented with vertical incidence sounder data at both ends of the path, a collateral Doppler sensing system, and coincident satellite solar data. A fully annotated database was prepared and is maintained by the Naval Ocean Systems Center Advanced Propagation Forecasting System (PROPHET).

• Research Organization: Naval Ocean Systems Center, San Diego, CA (USA)
• OSTI ID: 5383509
• Report Number(s): AD-A-168275/6/XAB; NOSC/TD-869
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
IONOSPHERE
VIRTUAL HEIGHT
SIGNALS
DETECTION
ACCURACY
CALIFORNIA
CESIUM
COLORADO
ERRORS
REFRACTION
RESOLUTION
ALKALI METALS
DIMENSIONS
EARTH ATMOSPHERE
ELEMENTS
FEDERAL REGION IX
FEDERAL REGION VIII
HEIGHT
METALS
NORTH AMERICA
PLANETARY IONOSPHERES
USA
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena