Altitude measurement system and associated methods

• US 7,095,364 B1
• Filed: 08/04/2005
• Issued: 08/22/2006
• Est. Priority Date: 08/04/2005
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Hoisington, Zachary C., Rawdon, Blaine K.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US11/197,405
• Time in Patent Office: 383 Days
• Field of Search: 382/154, 701 3- 13, 701/200, 701/207, 701/220, 367/87, 367 99-116, 356 401- 515, 356/28, 356/28.5, 181/123, 181/124, 73384-387, 702/127, 702/138, 702/139, 702/189, 702/198, 702/199, 342 25 R- 26 D, 342/118, 342120-122, 342165-175, 342189-197
• US Class Current: 342/120
• CPC Class Codes: G01S 13/08 Systems for measuring distance only indirect measurement G01S13/46
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 13/953 mounted on aircraft
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

An altitude measuring system and method for aircraft is provided. The altitude measuring system includes altitude sensors for providing data to an altitude processing unit. The altitude processing unit spatially averages each output to determine a mean altitude. Pitch and roll are accounted for by correction. A method of determining aircraft altitude from a plurality of altitude sensors includes receiving altitude sensor data from each sensor and spatially averaging the altitude sensor outputs to determine aircraft altitude. A method of estimating the maximum height of an ocean surface includes receiving a plurality of altitude sensor data and determining a mathematical description of the ocean surface from the sensor data. The maximum probable wave height of the ocean surface is estimated from the mathematical description. From the maximum wave height, a cruise altitude may be determined.

Claims

1. An altitude measuring system for aircraft, comprising:

a plurality of altitude sensors disposed in a plurality of locations on the aircraft, each altitude sensor providing altitude sensor data; and

an altitude processing unit in communication with each of the plurality of altitude sensors, wherein the altitude processing unit is capable of correcting each altitude sensor output to an altitude reference point, and wherein the altitude processing unit is further capable of spatially averaging the corrected altitude sensor output to determine a mean altitude.

2. The altitude measuring system according to claim 1, further comprising an inertial measurement unit providing aircraft attitude parameters selected from the group consisting of pitch and roll.

3. The altitude measuring system according to claim 1, further comprising a flight control computer for processing the altitude data to determine a flying altitude for the aircraft.

4. The altitude measuring system according to claim 1, wherein the altitude processing unit selectively weights the altitude sensor output.

5. The altitude measuring system according to claim 1, wherein the altitude processing unit is capable of correcting for pitch and roll of the aircraft.

6. The altitude measuring system according to claim 1, wherein the altitude processing unit examines the altitude sensor output for errors and omits errant outputs from the spatial average.

7. A method of determining aircraft altitude from a plurality of altitude sensors disposed in a plurality of locations on the aircraft, comprising:

receiving an altitude sensor data from each sensor;

correcting each of the altitude sensor data to an altitude reference point; and

spatially averaging the corrected altitude sensor data to determine aircraft altitude.

8. The method according to claim 7, wherein correcting the altitude sensor data comprises correcting for pitch and roll of the aircraft.

9. The method according to claim 7, further comprising examining each of the altitude sensor data for errors and omitting errant outputs from the spatially averaging step.

10. The method according to claim 7, further comprising filtering each of the altitude sensor data based upon frequency characteristics of the sensor data.

11. The method according to claim 10, further comprising calculating an expected value of the filtered altitude sensor data to provide an expected value of the altitude sensor data.

12. The method according to claim 11, further comprising spatially averaging the expected value to determine an expected aircraft altitude.

13. A method of estimating the maximum height of an ocean surface, comprising:

receiving a plurality of altitude sensor data spatially dispersed from different points about the aircraft;

determining a mathematical description of the ocean surface based upon the altitude sensor data; and

estimating the maximum probable wave height of the ocean surface from the mathematical description of the ocean surface.

14. The method according to claim 13, further comprising determining a cruise altitude for an aircraft based upon the maximum wave height.

15. The method according to claim 13, wherein determining the mathematical description comprises conducting a Fourier analysis of the amplitude, frequency and direction of the ocean surface.

16. The method according to claim 13, further comprising correcting the altitude sensor data to an altitude reference point prior to determining the mathematical description.

17. The method according to claim 16, wherein correcting the altitude sensor data comprises correcting for pitch and roll of the aircraft.

18. The method according to claim 16, further comprising examining the altitude sensor data for errors and omitting errant outputs prior to determining the mathematical description.