US 6,639,541 B1 · Device and method for detecting, measuring, and reporting low-level interference at a receiver

Abstract

An inexpensive, reliable apparatus and method for autonomously monitoring, measuring the incident level, recording, comparing, reporting, and optionally displaying an indication of intentional or unintentional low-power interfering signals or emissions, including naturally occurring emissions and reflections, as received at the input of an operating system. A particular application of this invention is to monitor, measure, record, compare, report and optionally display an indication of low level interference in the L1 and L2 bands of operation of the NAVSTAR Global Positioning System (GPS). The received signals in L1 and L2 bands are compared to a reference received signal in a third band. This comparison provides a sensitive means to detect the presence of an interfering emission or signal in the L1 band or the L2 band via canceling out the variation in the radiometric scene temperature. The reported data are used for dynamic decision making.

Claims16

Dependent claims

A monitoring system that may be associated with an operational system, said monitoring system operating to monitor sources of desirable and undesirable electromagnetic emissions present in a first frequency region containing pre-determined frequency bands in which at least some of the sources may interfere with said operational system that is receiving electromagnetic emissions with specific characteristics in said pre-determined frequency bands, comprising:

a receive assembly capable of detecting low levels of electromagnetic emissions, said receive assembly having an input and an output;
an antenna system operably connected to said input of said receive assembly, and
a processor in operable communication with said output of said receive assembly,
wherein said monitoring system receives and measures desirable and undesirable electromagnetic emissions in said first frequency region, compares said desirable and undesirable electromagnetic emissions in said first frequency region to a reference in a second frequency region separate from said first frequency region, records the results of said comparison, identifies indications of interference in said pre-determined frequency bands, and reports said indications of interference, said indications otherwise attainable only unreliably by using a spectrum analyzer or equivalent capability.

1 more element

A method for monitoring sources of desirable and undesirable electromagnetic emissions present in pre-determined frequency bands of an operation of an operational system having at least one antenna in which said sources may interfere with said operational system, said operational system operating to receive electromagnetic emissions having specific characteristics in said pre-determined frequency bands, comprising:

receiving indications of desirable and undesirable electromagnetic emissions within a first frequency region containing said predetermined frequency bands using at least one autonomous antenna suitable for receiving said electromagnetic emissions;
receiving indications of electromagnetic emissions as a reference signal within a second frequency region outside said first frequency region;
measuring characteristics of said desirable and undesirable electromagnetic emissions;
comparing said characteristics of said desirable and undesirable electromagnetic emissions to said reference signal within a second frequency region outside said first frequency region;
identifying indications of undesirable received electromagnetic emissions within said pre-determined frequency bands;
recording said characteristics of said undesirable electromagnetic emissions;
and
reporting selected characteristics of said undesirable electromagnetic emissions in a manner suitable for timely interpretation thereof,
wherein said receiving, measuring, comparing, recording, identifying, and reporting of said characteristics of said undesirable electromagnetic emissions within said pre-determined frequency bands of operation of said operational system is provided as input for dynamic decision making.

6 more elements

Dependencies are inferred from the claim text.

Device and method for detecting, measuring, and reporting low-level interference at a receiver

Life of this patent

Device and method for detecting, measuring, and reporting low-level interference at a receiver

Life of this patent

Abstract

Claims16