SYSTEM AND METHOD OF USING MEASUREMENTS OF OPPORTUNITY WITH VECTOR TRACKING FILTERS FOR IMPROVED NAVIGATION

• US 20150048972A1
• Filed: 07/10/2014
• Published: 02/19/2015
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Parsons Corporation (New Port Group Holdings, Inc.)
• Original Assignee: Echo Ridge, LLC
• Inventors: Kennedy, Joseph P., Carlson, John P.
• Granted Patent: US 9,739,891 B2
• Time in Patent Office: Days
• US Class Current: 342/357.29
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0242 Determining the position of transmitters to be subsequently used in positioning G01S5/0289 takes precedence
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks

Abstract

A system and method to opportunistically use measurements on a priori unknown radio signals, not intended for radio navigation or geolocation, to improve navigation/geolocation position estimation yield accuracy and efficiency.

Claims

1. A method of determining the location of a mobile device, comprising;

estimating a first position, velocity and timing (PVT) data of a mobile device;

receiving a first signal of opportunity (SoOP) at the mobile device, wherein the SoOP is an ambient radio frequency (RF) transmission that is not intended for navigation, position or timing purposes;

implementing a location algorithm to receive the first estimated PVT data and provide a second estimated PVT data for the mobile device;

implementing a vector tracking loop using the second estimated PVT data and the received first SoOP to provide a satellite tracking parameter data;

tracking a navigation satellite using the satellite tracking parameter data;

receiving navigation signals from the tracked navigation satellite; and

determining a third estimated PVT data for the mobile device from the received navigation signals.

2. The method of claim 1 wherein the first estimated PVT data for the mobile device is determined using a navigation signal received from a navigation satellite.

3. The method of claim 1 wherein the first estimated PVT data for the mobile device is determined using a second SoOP received at the mobile device.

4. The method of claim 1 wherein the first estimated PVT data for the mobile device is determined using an inertial measuring unit.

5. The method of claim 1 wherein the vector tracking loop uses data received from an inertial measuring unit of the mobile device to provide the navigation satellite tracking parameter data.

6. The method of claim 1 wherein the third estimated PVT data for the mobile device is provided to the vector tracking loop to provide the navigation satellite tracking parameter data.

7. The method of claim 1 wherein the first SoOP is at least one of a television broadcast, a cellular base station broadcast, a WiFi access point, or a satellite broadcast downlink.

8. The method of claim 1 wherein the third estimated PVT data for the mobile device and data received from an inertial measuring unit of the mobile device are provided to the vector tracking loop to provide the navigation satellite tracking parameter data.

9. The method of claim 1 further comprising the steps of continuously determining the navigation satellite tracking parameter data while selectively disabling the tracking of the navigation satellite for a predetermined period of time in order to conserve power consumed by the mobile device.

10. The method of claim 9 wherein the predetermined period of time is a function of the quality of the estimated PVT data.

11. A system for tracking the location of a mobile device, comprising:

a database of SoOP data and navigation satellite data;

an inertial navigation system associated with a mobile device;

an extended Kalman filter receiving input from the inertial navigation system and the database to provide first position, velocity, timing (PVT) data of the mobile device;

a vector tracking loop for receiving the first PVT data;

a satellite receiver for receiving the first PVT data from the vector tracking loop and determining second PVT data for the mobile device from a signal received from a navigation satellite;

a processor programmed to disable the vector tracking loop for a predetermined period of time in order to conserve power consumed by the mobile device;

wherein the extend Kalman filter provided third PVT data for the mobile device during the period in which the vector tracking loop is disabled.

12. The system of claim 11 wherein the predetermined period of time is a function of a quality of the estimated PVT data.