Reat-time WaveSmooth™ error mitigation for Global Navigation Satellite Systems

• US 20050212696A1
• Filed: 03/21/2005
• Published: 09/29/2005
• Est. Priority Date: 03/25/2004
• Status: Abandoned Application

• Current Assignee: Chris Gregory Bartone, Yujie Zhang
• Original Assignee: Chris Gregory Bartone, Yujie Zhang
• Inventors: Zhang, Yujie, Bartone, Chris Gregory
• Application Number:
  US11/087,022
• Publication Number:
  US 20050212696A1
• Time in Patent Office: Days
• US Class Current: 342/357.270
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/22 Multipath-related issues
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry

Abstract

WaveSmooth™ is a technique to mitigate inherent measurement error for GNSS signals. The WaveSmooth™ technique can be applied for single-frequency or multi-frequency GNSS users. For single-frequency GNSS users, WaveSmooth™ enables smoothing of GNSS measurements, in real-time using wavelets without introducing significant ionosphere divergence. For multi-frequency GNSS users, the WaveSmooth™ technique effectively mitigates multipath error in a real-time fashion. The WaveSmooth™ techniques utilizes wavelet aided methods and operate on the GNSS Code minus Carrier (CmC) signal to mitigate inherent GNSS measurement errors in a real-time fashion to improve the performance of these GNSSs. The WaveSmooth™ error mitigated pseudorange measurement can be used, along with the original carrier phase measurement for a high performance user solution.

Claims

1. WaveSmooth™

is a group of techniques that utilizes wavelet aided methods and operate on the Code minus Carrier (CmC) signal to mitigate inherent GNSS measurement errors in a real-time fashion to improve the performance of these GNSS.

2. A method according to claim 1 wherein said “

wavelet aided methods”

refer to all the GNSS error mitigation methods aided by wavelet techniques in an optimum state of art to mitigate inherent GNSS measurement error.

3. A method according to claim 1 wherein said “

wavelet aided methods”

refer to all the GNSS error mitigation methods aided by wavelet techniques utilizes spectrogram analysis to provide a time resolution representation of the multipath error component, and offers the unique ability to analyze the error characteristics at different frequencies and to localize them in time.

4. A method according to claim 1 wherein said “

group of techniques that” and

“

operate on the Code minus Carrier (CmC) signal” and

“

real-time fashion”

covers removal of the bias in the CmC signal in real-time to enable enhanced performance of the GNSS.

5. A method according to claim 1 wherein said “

inherent measurement errors”

covers all the possible error components inherent in a GNSS including receiver noise, multipath, atmospheric error, environmental error, ionospheric delay, temperature error, spatial error, temporal error, etc.

6. A method according to claim 1 wherein said “

performance”

is in terms of complexity, cost real-time, position, velocity, time, accuracy, reliability, integrity, availability and continuity, etc.

7. A method according to claim 1 wherein said “

improved performance”

is gained for whereby minimal recursive lag is introduced in the smoothing process, thus minimizes risk when the ionosphere error is not the same at each end of the baseline in DGPS architectures.

8. A method according to claim 1 wherein said “

improved performance”

is obtained whereby the WaveSmooth™

technique can be implemented in real-time for GNSS architectures.