Navigation Guidance for Aircraft Approach and Landing

• US 20080255715A1
• Filed: 04/10/2007
• Published: 10/16/2008
• Est. Priority Date: 04/10/2007
• Status: Abandoned Application

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Elchynski, Joseph J.
• Application Number:
  US11/733,349
• Publication Number:
  US 20080255715A1
• Time in Patent Office: Days
• US Class Current: 701/16
• CPC Class Codes: G01S 19/15 Aircraft landing systems
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial

Abstract

A system and method is described for providing pilots with navigational guidance when landing in low visibility conditions and/or at airports that do not contain a ground infrastructure in place to support precision approach. The navigational guidance is obtained by fusing one or more navigational algorithms and/or error models to improve navigation performance to near Instrument Landing System (ILS) performance levels. The navigational algorithms and error models include a gravity error model, a Global Positioning System (GPS) receiver measurement model, a Wide Area Augmentation System (WAAS) troposphere model, encrypted corrections, and a dynamic range error model.

Claims

1. A navigation system, comprising in combination:

a navigation processor that provides as an output a navigation solution; and

a Kalman filter that receives data from a GPS sensor and the navigation solution from the navigation processor, and estimates navigation corrections that are provided to the navigation processor, wherein the Kalman filter uses a dynamic range error model that changes as a function of ephemeris age.

2. The navigation system of claim 1, wherein the navigation processor uses a gravity error model to calculate the navigation solution when data from the GPS sensor is unavailable.

3. The navigation system of claim 2, wherein the gravity error model is a five arc-min gravity model.

4. The navigation system of claim 1, wherein the GPS sensor includes a measurement model based on a Precise Positioning Service (PPS) Accuracy Improvement Initiatives (AII).

5. The navigation system of claim 1, wherein the GPS sensor includes a Wide Area Augmentation System (WAAS) troposphere error model.

6. The navigation system of claim 1, wherein the navigation processor uses encrypted corrections to calculate the navigation solution.

7. The navigation system of claim 1, wherein the dynamic range error model weighs measurements from satellites with newer ephemeris more than satellites with older ephemeris.

8. The navigation system of claim 1, wherein the navigation solution is provided to a display that depicts glideslope symbology and localizer guidance.

9. A navigation system, comprising in combination:

a navigation processor that provides as an output a navigation solution; and

a Kalman filter that receives data from a Global Positioning System (GPS) sensor and the navigation solution from the navigation processor, and estimates navigation corrections that are provided to the navigation processor;

wherein the navigation processor uses a gravity error model to calculate the navigation solution when data from the GPS sensor is unavailable;

wherein the navigation processor uses encrypted corrections to calculate the navigation solution;

wherein the Kalman filter uses a dynamic range error model that changes as a function of ephemeris age;

wherein the GPS sensor includes a measurement model based on a Precise Positioning Service (PPS) Accuracy Improvement Initiatives (All); and

wherein the GPS sensor includes a Wide Area Augmentation System (WAAS) troposphere error model.

10. A method for providing pilots with navigational guidance when landing in low visibility conditions or at airports that do not contain a ground infrastructure in place to support precision approach, comprising in combination:

receiving data from at least one inertial sensor;

receiving data from at least one Global Positioning System (GPS) sensor, wherein the data from the at least one GPS sensor is calculated using a measurement model based on a Precise Positioning Service (PPS) Accuracy Improvement Initiatives (All) and a Wide Area Augmentation System (WAAS) troposphere error model;

calculating correction data using a dynamic range error model that changes as a function of ephemeris age; and

calculating a navigation solution based on the data received from the at least one inertial sensor and the correction data.

11. The method of claim 10, further comprising using a gravity error model to calculate the navigation solution when data from the GPS sensor is unavailable.

12. The method of claim 11, wherein the gravity error model is a five arc-min gravity model.

13. The method of claim 10, further comprising using encrypted corrections to calculate the navigation solution.

14. The method of claim 10, wherein the dynamic range error model weighs measurements from satellites with newer ephemeris more than satellites with older ephemeris.