Claims
- 1. A meter for use in characterizing signals received by an antenna, the meter including:
A. a first subsystem for determining estimates of parameters associated with a direct signal component and one or more multipath signal components of the received signal, the first subsystem determining estimates for one or more of amplitude, delay and phase of the signal components; B. a second subsystem for analyzing the parameters and determining if signal components that adversely affect the processing of the direct signal components are present.
- 2. The meter of claim 1 wherein the second subsystem
i. produces a ratio of the amplitudes of the direct and the respective one or more multipath components, and ii. determines the presence of signal components which adversely affect the processing of the direct signal components if the ratio falls below a predetermined value.
- 3. The meter of claim 1 wherein the second subsystem
i. produces correlation residual values for certain correlators used by the first subsystem, the second subsystem producing the correlator residual value for a given correlator by subtracting from a measured correlation value the contributions made by the direct and the one or more multipath signal components, and ii. determines the presence of signal components that adversely affect the processing of the direct signal components if certain of the correlator residual values are greater than a predetermined threshold.
- 4. The meter of claim 3 wherein the second subsystem further
iii. produces minimum detectable error values for certain correlators, where the minimum detectable error value is a direct signal correlation value normalized by the corresponding correlator value of a punctual correlator, iv. produces minimum detectable ratio values for certain sets of correlators, where the minimum detectable ratio is the ratio of a direct signal tracking error of a set of correlators at one location and a set of correlators at a second location, and v. determines the presence of signal components that adversely affect the processing of the direct signal components when one or both of the error values and ratio values exceed predetermined thresholds.
- 5. The meter of claim 1 wherein the signal components that adversely affect the processing of the direct signal components are signals associated with satellite failure.
- 6. The meter of claim 1 wherein the signal components that adversely affect the processing of the direct signals are excessive multipath signals.
- 7. The meter of claim 1 wherein the second subsystem monitors signal quality of the signals received from a given transmitting source and assigns confidence ratings to associated position measurements.
- 8. The meter of claim 1 further including a display for providing to a user an indication of the presence of the signal components that adversely affect the processing of the direct signal components.
- 9. The meter of claim 8 wherein the display presents a plot of one or more values associated with signal quality.
- 10. The meter of claim 1 wherein the second subsystem analyses the parameters associated with signals received over a predetermined time period to determine if a location is acceptable as an antenna site.
- 11. The meter of claim 1 wherein the second subsystem determines if excessive multipath signals are present during the predetermined time period.
- 12. The meter of claim 11 wherein the second subsystem further determines at what times excessive multipath signals are present.
- 13. The meter of claim 12 wherein the second subsystem determines that a location is not acceptable as an antenna site if excessive multipath signals are present for more than a certain portion of the predetermined time period.
- 14. The meter of claim 1 wherein the second subsystem further
i. produces minimum detectable error values for certain correlators, where the minimum detectable error value is a direct signal correlation value normalized by the corresponding correlator value of a punctual correlator, ii. produces minimum detectable ratio values for certain sets of correlators, where the minimum detectable ratio is the ratio of a direct signal tracking error of a set of correlators at one location and a set of correlators at a second location, and iii. determines the presence of signal components that adversely affect the processing of the direct signal components when one or both of the error values and ratio values exceed predetermined thresholds.
- 15. A system for use in characterizing signals received by an antenna, the system including:
A. a signal receiver for determining estimates of parameters associated with a direct signal component and one or more multipath signal components of the received signal, the receiver determining estimates for one or more of amplitude, delay and phase of the signal components; B. a meter for analyzing the parameters and determining if signal components that adversely affect position measurements are present.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from U.S. Provisional Patent Application Ser. No. 60/178,115, which was filed on Jan. 26, 2000, by Bryan Townsend, Jonathan Wiebe and Andy Jakab for a MULTIPATH METER and is hereby incorporated by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60178115 |
Jan 2000 |
US |