发明名称 |
HF BACKGROUND NOISE MEASUREMENT IN HF ENVIRONMENTS |
摘要 |
A frequency surveillance method for monitoring background atmospheric noise levels in unoccupied channels in an operating frequency band of a high frequency communication system. In the method, the unoccupied channels are scanned a number of times to obtain analogue signals. The obtained signals are transformed to a digital form and averaged. The averaged digital signals are filtered to remove substantially all radio frequency interference. Absolute signals are then produced by scaling or comparing the filtered signals with a known noise level. The background noise levels are obtained by further averaging the absolute signals. A visual display unit is used to display the background noise levels as functions of frequencies. A frequency surveillance apparatus is also disclosed. |
申请公布号 |
WO9219981(A1) |
申请公布日期 |
1992.11.12 |
申请号 |
WO1992AU00197 |
申请日期 |
1992.05.01 |
申请人 |
THE COMMONWEALTH OF AUSTRALIA C/O THE SECRETARY, D |
发明人 |
EARL, GEORGE, FREDERICK;WARD, BRUCE, DONALD |
分类号 |
G01R23/16;G01R29/26;G01S7/02;G01S7/295;G01S7/40;G01S7/42;G01S13/02;H04B7/00;H04B17/00 |
主分类号 |
G01R23/16 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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