Satellite measurement screening to protect the integrity of existing monitors in the presence of phase scintillation

Patent metadata

Field	Value
Publication number	US-9964645-B2
Application number	US-201414193773-A
Country	US
Kind code	B2
Filing date	Feb 28, 2014
Priority date	Feb 28, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A method of implementing a real-time screening process for phase scintillation is presented. The method includes detecting a phase scintillation event during a sample time period at a phase scintillation monitor; excluding associated satellite measurement data from further use based on the detection of the phase scintillation event at the phase scintillation monitor; detecting an end to the phase scintillation event at the phase scintillation monitor; and readmitting associated satellite measurement data collected after the end of the phase scintillation event as detected by the phase scintillation monitor.

First claim

The invention claimed is:

1. A method of implementing a real-time screening process for phase scintillation, the method comprising:
detecting a phase scintillation event during a sample time period at a phase scintillation monitor;
excluding associated satellite measurement data from further use based on the detection of the phase scintillation event at the phase scintillation monitor;
detecting an end to the phase scintillation event at the phase scintillation monitor; and
readmitting associated satellite measurement data collected after the end of the phase scintillation event as detected by the phase scintillation monitor.

2. The method of claim 1 , further comprising:
calculating satellite (SV) motion and SV clock corrected carrier rates for reference receiver/satellite pairs for which accumulated delta range data is available;
compensating a SV motion and a SV clock corrected carrier rate for a reference receiver clock by subtracting an average of all the other SV motion and SV clock corrected carrier rates from the SV motion and SV clock corrected carrier rates; and
calculating a reference receiver de-trended SV motion and SV clock corrected carrier rate for the reference receiver/satellite pairs in a sample time period.

3. The method of claim 2 , further comprising:
computing a carrier phase estimate using numerical integration;
calculating a sample average of the carrier phase estimate for the reference receiver/satellite pairs; and
calculating a variation in the carrier phase estimate for the reference receiver/satellite pairs in the current sample time period.

4. The method of claim 1 , wherein detecting the phase scintillation event during the sample measurement at the phase scintillation monitor comprises:
determining a phase scintillation monitor discriminator in a current sample time period for at least one reference receiver/satellite pair meets exclusion criteria.

5. The method of claim 4 , wherein determining the phase scintillation monitor discriminator in the current sample time period for at least one reference receiver/satellite pair meets the exclusion criteria comprises:
determining the phase scintillation monitor discriminator in the current sample time period for the at least one reference receiver/satellite pair is one of: greater than an exclusion threshold; or equal to the exclusion threshold.

6. The method of claim 1 , wherein detecting the end to the phase scintillation event comprises:
determining a phase scintillation monitor discriminator in the current sample time period for an excluded reference receiver/satellite pair meets readmittance criteria.

7. The method of claim 6 , wherein determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair meets the readmittance criteria comprises:
determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair is less than a readmit threshold.

8. The method of claim 6 , wherein determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair meets the readmittance criteria comprises:
determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair is less than a readmit threshold for a preselected number of samples.

9. The method of claim 6 , wherein determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair meets the readmittance criteria comprises:
determining the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair is less than a readmit threshold for a preselected number of consecutive samples.

10. A phase scintillation monitor to provide real-time screening for phase scintillation, comprising:
at least one processor communicatively coupled to receive input from a plurality of reference receivers; and
a storage medium tangibly embodying program instructions for execution by the at least one processor, wherein the program instructions are operable, when executed by the at least one processor, to:
detect a phase scintillation event during a sample time period;
exclude associated satellite measurement data from further use based on the detection of the phase scintillation event;
detect an end to the phase scintillation event; and
readmit associated satellite measurement data collected after the end of the phase scintillation event.

11. The phase scintillation monitor of claim 10 , wherein the program instructions to detect the phase scintillation event during the sample measurement are further operable, when executed by the at least one processor, to:
determine a phase scintillation monitor discriminator in a current sample time period for at least one reference receiver/satellite pair meets exclusion criteria.

12. The phase scintillation monitor of claim 11 , wherein the program instructions operable to determine the phase scintillation monitor discriminator in the current sample time period for the at least one reference receiver/satellite pair meets the exclusion criteria include program instructions operable, when executed by the at least one processor, to:
determine the phase scintillation monitor discriminator in the current sample time period for the at least one reference receiver/satellite pair is one of: greater than an exclusion threshold; or equal to the exclusion threshold.

13. The phase scintillation monitor of claim 10 , wherein the program instructions operable to detect the end to the phase scintillation event include program instructions operable, when executed by the at least one processor, to:
determine a phase scintillation monitor discriminator in a current sample time period for an excluded reference receiver/satellite pair meets readmittance criteria.

14. The phase scintillation monitor of claim 13 , wherein the program instructions operable to determine the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair meets the readmittance criteria include program instructions operable, when executed by the at least one processor, to:
determine the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair is less than a readmit threshold.

15. The phase scintillation monitor of claim 13 , wherein the program instructions operable to determine the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair meets the readmittance criteria include program instructions operable, when executed by the at least one processor, to:
determine the phase scintillation monitor discriminator in the current sample time period for the excluded reference receiver/satellite pair is less than a readmit threshold for a preselected number of samples.

16. The phase scintillation monitor of claim 10 , wherein the program instructions are further operable, when executed by the at least one processor, to cause the phase scintillation monitor to:
calculate a phase scintillation monitor discriminator in a current sample time period for at least one reference receiver/satellite pair.

17. The phase scintillation monitor of claim 16 , wherein the program instructions to calculate the phase scintillation mo

Assignees

• Honeywell Int Inc

Inventors

• Scheitlin Joseph E
• Brenner Mats Anders
• Class Kim A
• Johnson Bruce G
• Reuter Randy J
• Howard John M

Classifications

• G01S19/071

  DGPS corrections · CPC title

• G01S19/15

  Aircraft landing systems · CPC title

• G01S19/08

  providing integrity information, e.g. health of satellites or quality of ephemeris data · CPC title

• G01S19/20 Primary

  Integrity monitoring, fault detection or fault isolation of space segment · CPC title

• G01S19/07 Primary

  providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections · CPC title