Accession Number : ADA264670


Title :   Radiolocation of a Satellite-Borne LOVHF Beacon


Corporate Author : NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA


Personal Author(s) : Rose, Robert B


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264670.pdf


Report Date : Nov 1992


Pagination or Media Count : 9


Abstract : A year long experimental program was conducted to measure refractive bending, or how much the signal deviates from true line of sight, at low VHF frequencies (29.5 MHz), and to determine whether this deviation or error could be predicted using large scale ionospheric models such as the Ionospheric Conductivity and Electron Density (ICED) program. An experiment to directly measure the angle of arrival of a 29.5 MHz signal from an orbiting satellite was successfully completed. The satellite was in a circular orbit at an altitude of 1000 km. It was shown that refractive errors can be directly related to the electron density along the measurement slant range. Ionospheric disturbances such as sporadic E and ionospheric storms produce large, short term errors that can approach 10 degrees. In addition to day/night variations, seasonal and solar cycle sensitivities were found. The refractive error varied so rapidly with respect to time and space that its prediction with a median value ionospheric code is almost impossible. Propagation, Prophet, Expert systems Propagation forecast, Solar disturbances,


Descriptors :   *BENDING , *IONOSPHERIC MODELS , *ATMOSPHERIC REFRACTION , *RADIO BEACONS , *LOCATORS , FREQUENCY , LINE OF SIGHT , ORBITS , PROPAGATION , REPRINTS , DENSITY , MEASUREMENT , TIME , NIGHT , EXPERT SYSTEMS , STORMS , ARTIFICIAL SATELLITES , ERRORS , SIGNALS , SCALE , ELECTRONS , VARIATIONS , SOLAR DISTURBANCES , CIRCULAR ORBITS , APPROACH , IONOSPHERIC DISTURBANCES , SATELLITE ATTITUDE , RADIO DIRECTION FINDERS , SLANT RANGE , SOLAR CYCLE , ARRIVAL , VALUE , VISION , CYCLES , POSITION(LOCATION) , PREDICTIONS , MODELS , CONDUCTIVITY , ELECTRON DENSITY , ANGLE OF ARRIVAL


Subject Categories : Atmospheric Physics
      Optics
      Radio Communications


Distribution Statement : APPROVED FOR PUBLIC RELEASE