Phase-locked reception of radio transmissions from earth satellites : concepts, design and applications to the study of ionosphere

Nowland, Wayne L. (1975). Phase-locked reception of radio transmissions from earth satellites : concepts, design and applications to the study of ionosphere PhD Thesis, School of Physical Sciences, The University of Queensland. doi:10.14264/uql.2015.524

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
THE5397.pdf Thesis (fulltext) application/pdf 8.36MB 7

Author Nowland, Wayne L.
Thesis Title Phase-locked reception of radio transmissions from earth satellites : concepts, design and applications to the study of ionosphere
School, Centre or Institute School of Physical Sciences
Institution The University of Queensland
DOI 10.14264/uql.2015.524
Publication date 1975
Thesis type PhD Thesis
Supervisor K. L. Jones
Total pages 264
Language eng
Subjects 02 Physical Sciences
Formatted abstract
An electronic system has been designed to monitor the total electron content (TEC) of the ionosphere. This is accomplished by measuring propagation effects, specifically Faraday rotation and dispersive-Doppler phase shift, on VIIF/UHF transmissions from artificial Earth satellites.

Special phase-locked receivers are used to receive the 137,35 MHz radio signal from the geostationary satellite ATS-1 as well as the 150 and 400 MHz transmissions from five low altitude polar orbiting satellites comprising the U.S. Navy Navigation Satellite System (NNSS). Continuous Faraday rotation measurements are performed on the ATS-1 signal using a mechanical rotating Yagi antenna polarimeter while MSS polarization measurements are achieved with a spaced helical antenna polarimeter incorporating a dual phase-locked receiver which detects the phase difference between the outputs of the two oppositely polarized receiving antennas. Dispersive- Doppler phase shift measurements on the phase coherent 150 and 400 MHz NNSS transmissions are also accomplished with a dual phase-locked receiver.

ATS-1 measurements are recorded in analogue form on slow speed chart recorders providing polarization and time resolutions better than 5° and 1 minute respectively. Digital techniques are utilized in recording NNSS data with analogue chart recorder outputs providing simultaneous visual representation. Conputer compatible magnetic tape format allows optimum transfer of data from the recording system to off-line computers.

While a significant section of this thesis is devoted to the concepts and design of the instrumentation, a prime objective of the research has been to assess the spatial and temporal behaviour of the mid-latitude F-region using the ground based TEC observations which this experiment provides. Various methods have been investigated for converting the raw data into measurements of TEC.

TEC observations provided by this experiment as well as ionosonde foF2 (F2 layer critical frequency) data from four Eastern Australian stations have been used to study gross morphological features of the mid-latitude F-region. This data is supplemented with Brisbane hmF2 (F2 layer peak height) variations and thermospheric wind measurements from the Mt. Torrens station near Adelaide. Several striking features were discovered. An apparent accumulation of F-region ionization during Winter sunset was detected over the geographic latitude range 28 – 32°S. This was associated with excessively large horizontal ionization gradients to the North and South of the "plasma pile-up" region. A peculiar feature, probably an extension of the sunset plasma pile-up phenomenon, was also observed during all Winter nocturnal periods.

F-region ionospheric irregularities have been studied. Temporal variations with periods 15 - 300 mins and spatial structures having scale sizes 30 - 2000 km were detected. A large number of these irregularities are identified as F-region travelling ionospheric disturbances (TID's). Measurement of their horizontal phase velocity components has allowed an experimental determination of the dispersion relation for F-region TID's. Moderate agreement with theoretical dispersion curves for internal atmospheric gravity waves highlights the correlation between observed TID's and internal neutral atmospheric gravity waves which propagate at F-region heights.
Keyword Ionospheric electron density -- Measurement
Ionospheric radio wave propagation
Artificial satellites -- Radio observations
Additional Notes Other Title: Radio transmissions from earth satellites.

Document type: Thesis
Collection: UQ Theses (RHD) - UQ staff and students only
Citation counts: Google Scholar Search Google Scholar
Created: Fri, 23 Jan 2015, 11:43:13 EST by Mary-Anne Marrington on behalf of Scholarly Communication and Digitisation Service