Accession Number : ADA191894

Title :   Data Needed to Verify/Quantify Models,

Corporate Author : NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA

Personal Author(s) : Paul, Adolf K

PDF Url : ADA191894

Report Date : Aug 1986

Pagination or Media Count : 11

Abstract : Advanced digital ionosondes have mainly two advantages compared with the classical with the classical analog systems: they are able to record the full information content of an echo reflected from the ionosphere with high precision in digital form and in many instances those data can be processed on a computer with little or no interaction by an operator. An echo is characterized by its frequency, travel time, or virtual height, amplitude and phase relative to the phase of the transmitted pulse. The frequency is related to the plasma frequency or electron density at the reflection point, the virtual heights are needed for the computation of electron density profiles, while the amplitude is mainly determined by the absorption coefficient along the path of the signal. The most complex information is contained in the phase, the polarization of an echo can be obtained from the change of the phase with antenna orientation, the change of the phase with antenna orientation, the change of phase with frequency permits improved precision of the virtual heights, the change of phase with time is the doppler frequency and the variation of the phase with distance of over a plane yields the angle of arrival. The automatization makes the processing more economic permitting for instance much higher temporal resolution than the standard one ionogram per hour sequence.

Descriptors :   *DOPPLER EFFECT, *ELECTRON DENSITY, *IONOSPHERE, *PLASMAS(PHYSICS), ABSORPTION COEFFICIENTS, ANALOG SYSTEMS, ANGLE OF ARRIVAL, ANTENNAS, FREQUENCY, ORIENTATION(DIRECTION), PATHS, POLARIZATION, PROFILES, REFLECTION, SIGNALS, TRAVEL TIME, VARIATIONS, YIELD

Subject Categories : Plasma Physics and Magnetohydrodynamics
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE