Accession Number : ADA254347


Title :   ELF/VLF Generation


Descriptive Note : Scientific rept. no. 2


Corporate Author : ARCO POWER TECHNOLOGIES INC WASHINGTON DC


Personal Author(s) : Short, Robert D ; Papadopoulos, Dennis


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254347.pdf


Report Date : 31 Aug 1991


Pagination or Media Count : 89


Abstract : A preliminary analysis of the results of the ELF experimental campaigns conducted in the May - September 1990 time frame using the HIPAS transmitter in conjunction with the UCLA ELF receiver at the NOAA site and the mobile NUSC receiver is presented. Following a discussion of the critical physics issues and scalings relating to practical implementation of ionospherically generated ELF to submarine communications, the results of the two campaigns are presented. The data show conclusively that the measured ELF are low frequency signals generated by modulated ionospheric currents and not by nonlinear interference effects of the modulated HF. For the HIPAS parameters the received ELF signals are consistent with an equivalent Horizontal Magnetic Dipole (HMD) located at an altitude of 75 km radiating with an average dipole moment M 6x10 to the 8th power A-m sq. The maximum M value achieved during the campaign was 9x10 to the 8th power A-m sq. Results related to conversion efficiency scaling with HF polarization, low duty and painting operation, ELF frequency and ionospheric conditions, along with suggestions for future studies are also presented.


Descriptors :   *RADIOFREQUENCY , *VERY LOW FREQUENCY , *EXTREMELY LOW FREQUENCY , IONOSPHERE , PROPAGATION , POLARIZATION , WAVEGUIDES , UNDERWATER COMMUNICATIONS , IONOSPHERIC MODIFICATION , MAGNETIC DIPOLES , LOW FREQUENCY , WAVE PROPAGATION , ANISOTROPY , INTERFERENCE , SUBMARINES


Subject Categories : Atmospheric Physics
      Radiofrequency Wave Propagation
      Radio Communications


Distribution Statement : APPROVED FOR PUBLIC RELEASE