The frequency management system of the Jindalee over‐the‐horizon backscatter HF radar

Abstract

Real-time frequency management is a vital element in the effective operation of an over-the-horizon backscatter (OTH-B) HF radar. In the case of the Australian project Jindalee OTH-B HF radar, a comprehensive frequency management system has been developed for this purpose. The frequency management system includes subsystems for ionospheric backscatter, vertical and oblique incidence sounding, HF spectral surveillance, and incorporates a low powered backscatter radar. The system is capable of providing real-time frequency management advice to the main radar, and of acquiring synoptic data for off-line analysis. In this paper we describe the hardware architecture and signal processing schemes, together with sample data, for each of the subsystems. We then describe the manipulation of the environmental data in order to provide frequency management advice to the main radar.behavior of the ionosphere can adequately be de-automation, in order that the advice did not require scribed in this manner, the ionosphere is specialist interpretation. The second requirement was characterized by large fluctuations about the for the system to gather data routinely (nominally 24 monthly median [Rush et al., 1974; Paul, 1983]. hours per day) with the objective of building up a Hence, as communicators have sought enhanced per-synoptic data base of the propagation environment, formance from HF circuits (e.g., the transmission of even when the main radar was not in use. In order digital data), it has been recognized that there is a that the data base could be used to provide quantitaneed for real-time frequency management of such cir-tire estimates of radar performance, all data had to cuits [CCIR, 1982]. be calibrated. The operation of an HF radar represents one ofThe purpose of this paper is to describe the design the most demanding applications of the ionosphere and capabilities of the system together with some as a transmission channel for radiowaves. Successful initial results. We also describe the manipulation of operation of such a radar necessitates careful selec-the environmental data to provide operational data tion of the operating frequency, based upon the cur-to the main radar. The statistical analysis of the derent state of the ionosphere, combined with the spe-tailed synoptic measurements will be reported in subsequent papers, while application of the system to the problem of providing frequency management support Copyright 1987 by the American Geophysical Union. to the main radar for the purpose of remote sea state Paper number 6S0553. sensing has already been reported [Earl and Ward, 0048.6604/87/006s-0553508.00 1986'].

Investigation on fading of high frequency radio signals propagating in the ionosphere - results from a Jindalee radar experiment

“…The centre frequency and bandwidth of the signals were based on the spectral availability at the time of transmission, determined by the frequency management system (FMS) of the Jindalee OTH radar [3]. Unfortunately the radar was not set up optimally.…”

Modeling the recorded spectrum and reconstructing the transfer function of the wideband ionospheric HF radio channel in the case of chirp sounding

“…Ionosondes using a continuous chirp signal with a large base (chirp ionosondes) are an example of practical application of wideband signals [1][2][3][4][5]. Primary processing of the information signal in the chirp ionosondes is performed by the correlation-filtering (heterodyne) method [6][7][8].…”

MIMO High Frequency Surface Wave Radar Using Sparse Frequency FMCW Signals

“…The carrier frequency of each transmitting element is chosen in the guidance of current spectrum environment. Therefore, a frequency management subsystem should be cooperated to assist the main radar system which is already a common practice for currently deployed HF surface wave or skywave radars [38][39][40][41]. The frequency management subsystem monitors the spectrum environment, evaluates the monitoring results, and finally gives suggestions for frequency selection in real-time.…”