Doppler shift and spread study for ionospherically propagated signals
Vincent, Wilbur R.
MetadataShow full item record
Modern, High Frequency (HF) communication techniques, such as spread spectrum and frequency hopping, require precise signal frequency information. The predominant HF propagation path is via the ionosphere, which often produces Doppler frequency shift and spread. This study examined the frequency spectra of selected HF signals traversing short and long mid-latitude paths and one high- latitude auroral zone path. Signal amplitude and Doppler shifts and spreads observed show diurnal, carrier frequency and ionospheric path dependencies. Higher frequency signals experienced more Doppler shift, especially during the daytime. Spectrum spreading was more pronounced at night and was affected by multiple reflections, the auroral oval and field-aligned ionization. Additional signal observations are needed to cover seasonal variations, disturbed ionospheric conditions and solar cycle variations. The impact of Doppler shift and spread on wide-spectrum HF communications also needs to be examined
Approved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Effects of non-uniform windowing on the performance of a fast frequency-hopped noncoherent MFSK receiver over Rician fading channels with partial-band interference and Doppler shift Vece, Thomas W. (Monterey, California. Naval Postgraduate School, 1991-06);An error probability analysis is done for a DFT based, M-ary frequency-shift keying (MFSK) communications system employing fast frequency-hopped spread spectrum signals. A linear combination procedure referred to as ...
Sng, Sin Hie (Monterey California. Naval Postgraduate School, 2004-06);The radio channel places fundamental limitations on the performance of mobile ad hoc wireless networks. In the mobile radio environment, fading due to multipath delay spread impairs received signals. The purpose of this ...
Performance analysis of high frequency single-site-location antenna arrays using numerical electromagnetic modeling Schiantarelli, Harry Thornberry (Monterey California. Naval Postgraduate School, 1990-09);Electronic support measures (ESM) systems play an increasingly important role in modern warfare and can influence the outcome of a military engagement. The application of ESM can be extended to anti-guerrilla and anti-drug ...