Yiqun Chen

US Patent:

20120182181, Jul 19, 2012

Filed:

May 17, 2011

Appl. No.:

13/109025

Inventors:

Liwen L. Dai - Chino Hills CA, US
Michael A. Zeitzew - Redondo Beach CA, US
Yiqun Chen - Torrance CA, US
Yujie Zhang - Lomita CA, US

International Classification:

G01S 19/48

US Classification:

34235731

Abstract:

A satellite clock error is determined for each navigation satellite based on the pseudo-range code measurements, the carrier phase measurements, and broadcast satellite clock errors provided by a receiver network. Differences are determined between the computed satellite clock errors and the broadcast clock errors for each satellite. For each constellation, a clock reference satellite is selected from among the navigation satellites, where the clock reference satellite has the median value of clock error difference for that satellite constellation. A correction is determined for the broadcast clock error by applying a function of the reference satellite's clock error to the broadcast clock error for each satellite in the one or more constellations.

US Patent:

20220252732, Aug 11, 2022

Filed:

Sep 22, 2021

Appl. No.:

17/448390

Inventors:

- Moline IL, US
Yiqun Chen - Culver City CA, US

International Classification:

G01S 19/07

Abstract:

A first pair of a wide-lane (WL), zero-difference (ZD) bias filter and corresponding supplemental WL bias predictive filter determines the time-variant wide-lane bias for a corresponding satellite based on adaptive estimation responsive to tuned dynamic noise provided by the supplemental wide-lane bias predictive filter for each satellite. A second pair of narrow-lane (NL), zero-difference (ZD) bias filter and corresponding NL bias filter/code-phase bias filter determines the time-variant narrow-lane bias (e.g., refraction corrected (NL) code-phase bias) for a corresponding satellite based on adaptive estimation on adaptive estimation responsive to tuned dynamic noise within a narrow-lane bias/code-phase bias filter for each satellite. The electronic data processor of a data processing center is configured to provide a correction signal comprising the wide-lane ambiguities, the time-variant wide-lane bias and the narrow-lane ambiguities and the time-variant narrow lane bias.

US Patent:

20170269222, Sep 21, 2017

Filed:

Sep 6, 2016

Appl. No.:

15/257092

Inventors:

- Moline IL, US
Sonia U. Kuntz - Redondo Beach CA, US
Yujie Zhang - Torrance CA, US
Yiqun Chen - Torrance CA, US

International Classification:

G01S 19/41
G01S 19/07
G01S 19/44

Abstract:

A wide-lane ambiguity and a respective satellite wide-lane bias are determined for the collected phase measurements for each satellite for assistance in narrow-lane ambiguity resolution. Satellite correction data is determined for each satellite in an orbit solution based on the collected raw phase and code measurements and determined orbital narrow-lane ambiguity and respective orbital satellite narrow-lane bias. A slow satellite clock correction is determined based on the satellite orbital correction data, the collected raw phase and code measurements, and clock narrow-lane ambiguity and respective satellite narrow-lane bias. A low latency clock module or data processor determines lower-latency satellite clock correction data or delta clock adjustment to the slow satellite clock based on freshly or recently updated measurements of the collected raw phase measurements that are more current than a plurality of previous measurements of the collected raw phase measurements used for the slow satellite clock correction to provide lower-latency clock correction data.

US Patent:

20170269223, Sep 21, 2017

Filed:

Mar 2, 2017

Appl. No.:

15/448457

Inventors:

- Moline IL, US
Liwen L. Dai - Torrance CA, US
Yiqun Chen - Torrance CA, US

International Classification:

G01S 19/41
G01S 19/32
G01S 19/44
G01S 19/07

Abstract:

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines wide-lane navigation solutions for the plurality of reference receivers. The system also determines clusters of single-difference (SD) wide-lane ambiguity values, each cluster comprising pairs of SD wide-lane floating ambiguities for respective pairs of satellites. A satellite wide-lane bias value for each satellite of a plurality of satellites is initially determined in accordance with fractional portions of the SD wide-lane floating ambiguities in the clusters, and then periodically updated by applying SD wide-lane integer constraints in a Kalman filter. A set of navigation satellite corrections for each satellite, including the satellite wide-lane bias value for each satellite, is generated and transmitted to navigation receivers for use in determining locations of the navigation receivers.

US Patent:

20170269224, Sep 21, 2017

Filed:

Mar 2, 2017

Appl. No.:

15/448466

Inventors:

- Moline IL, US
Liwen L. Dai - Torrance CA, US
Yiqun Chen - Torrance CA, US

International Classification:

G01S 19/41
G01S 19/32
G01S 19/44
G01S 19/07

Abstract:

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines narrow-lane navigation solutions for the plurality of reference receivers. The system also determines clusters of single-difference (SD) narrow-lane floating ambiguities, each cluster comprising pairs of SD narrow-lane floating ambiguities for respective pairs of satellites. A satellite narrow-lane bias value for each satellite of a plurality of satellites is initially determined in accordance with fractional portions of the SD narrow-lane floating ambiguities in the clusters, and then periodically updated by a Kalman filter. A set of navigation satellite corrections for each satellite, including the satellite narrow-lane bias value for each satellite, is generated and transmitted to navigation receivers for use in determining locations of the navigation receivers.

US Patent:

20170269225, Sep 21, 2017

Filed:

Mar 2, 2017

Appl. No.:

15/448474

Inventors:

- Moline IL, US
Yiqun Chen - Torrance CA, US
Yujie Zhang - Torrance CA, US

International Classification:

G01S 19/41
G01S 19/32
G01S 19/44
G01S 19/07

Abstract:

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines wide-lane navigation solutions for the plurality of reference receivers. The system also determines clusters of single-difference (SD) wide-lane floating ambiguities. A satellite wide-lane bias value for each satellite of a plurality of satellites is initially determined in accordance with fractional portions of the SD wide-lane floating ambiguities in the clusters and over-range adjustment criteria. A set of navigation satellite corrections for each satellite, including the satellite wide-lane bias value for each satellite, is generated and transmitted to navigation receivers for use in determining locations of the navigation receivers.

US Patent:

20170269226, Sep 21, 2017

Filed:

Mar 2, 2017

Appl. No.:

15/448481

Inventors:

- Moline IL, US
Sonia Kuntz - Torrance CA, US
Yiqun Chen - Torrance CA, US
Yujie Zhang - Torrance CA, US

International Classification:

G01S 19/41
G01S 19/07
G01S 19/32

Abstract:

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines narrow-lane navigation solutions for the plurality of reference receivers. The system also determines, in accordance with the narrow-lane navigation solutions, at a first update rate, an orbit correction for each satellite of a plurality of satellites; at a second update rate, a clock correction for each such satellite; and at a third update rate that is faster than the second update rate, an update to the clock correction for each such satellite. Further, the system generates navigation satellite corrections for each such satellite, including the orbit correction updated at the first update rate, and the clock correction that is updated at the third update rate.