Position correction in sodar and meteorological lidar systems

1. A system for correcting wind speed and direction data collected by a sodar or lidar apparatus for at least the orientation of the apparatus, comprising:

one or more sensors mounted to the sodar or lidar apparatus that detect at least the three-dimensional angular orientation of the apparatus;

a processor that uses the detected three-dimensional angular orientation and a correction algorithm to correct in situ the wind speed and direction data in three dimensions for deviations from some nominal orientation, and that detects failures of the one or more sensors and in response to the detection of a failure uses the last valid orientation information to correct the wind speed and direction data; and

a database that stores; an identification of the correction algorithm; the detected three-dimensional angular orientation of the apparatus; and the corrected wind speed and direction data.

2. The system of claim 1 further comprising one or more additional sensors mounted to the apparatus that detect the position of the apparatus.

3. The system of claim 2 in which the database further stores data indicative of the detected position of the apparatus.

4. The system of claim 1 in which the processor performs the corrections in real time, based on orientation measured on a continuing basis to maintain reliable data accuracy even in the presence of post-installation positional shift of the apparatus which might otherwise degrade data accuracy.

5. The system of claim 1 in which directional orientation is measured with an electronic two or three axis compass, and tilt from vertical is measured with a two axis accelerometer-based inclinometer.

6. The system of claim 5 , further comprising a third accelerometer axis.

7. The system of claim 6 , further comprising one or more gyroscopes or other angular acceleration measurement sensors to also account for angular motion of the apparatus, along with motion along horizontal axes, to properly distinguish between angular inclinations and axial accelerations of the apparatus to correct for dynamic motions of the apparatus.

8. The system of claim 1 further comprising a GPS receiver that is used to measure the position of the apparatus.

9. The system of claim 8 where the GPS receiver also measures directional orientation.

10. A method of correcting wind speed and direction data collected by a sodar or lidar apparatus for at least the orientation of the apparatus, comprising:

using sensors mounted to the sodar or lidar apparatus to detect at least the three-dimensional angular orientation of the sodar or lidar apparatus;

using the detected three-dimensional angular orientation and a correction algorithm to correct in situ the wind speed and direction data in three dimensions for deviations from some nominal orientation;

storing in a database: an identification of the correction algorithm; the detected three-dimensional angular orientation; and the corrected wind speed and direction data; and

detecting failures of the one or more sensors, and in response to the detection of a failure using the last valid orientation information to correct the wind speed and direction data.

11. The method of claim 10 further comprising detecting the position of the apparatus.

12. The method of claim 11 in which data indicative of the detected position of the apparatus is also stored in the database.

13. The method of claim 10 in which the correction occurs in real time, based on orientation measured on a continuing basis to maintain reliable data accuracy even in the presence of post-installation position or angular shift of the apparatus which might otherwise degrade data accuracy.

14. The method of claim 11 in which directional orientation is measured with an electronic two or three axis compass, and tilt from vertical is measured with a two axis accelerometer-based inclinometer.

15. The method of claim 10 , in which angular accelerations, velocities and orientation of the apparatus is measured using one or more gyroscopes, solid-state gyroscopes, or other angular measurement sensors to properly distinguish between angular inclinations and axial accelerations of the apparatus to correct for dynamic motions of the apparatus.

16. The method of claim 10 in which the position of the apparatus is measured using a GPS receiver.

17. The method of claim 16 in which the GPS receiver also measures directional orientation of the apparatus.

18. The method of claim 10 in which the corrections are based on information provided at least in part by a user.

19. The method of claim 18 in which the corrections are based on orientation data input by a user.

20. A method of correcting wind speed and direction data collected by a sodar or lidar apparatus for the orientation and/or position of the apparatus, comprising:

providing at least the three-dimensional angular orientation of the sodar or lidar apparatus, in which the three-dimensional angular orientation is provided at least in part with one or more instruments coupled to the sodar or lidar apparatus;

using the provided three-dimensional angular orientation and a correction algorithm to correct in situ the wind speed and direction data in three dimensions for deviations from some nominal orientation;

storing in a database: an identification of the correction algorithm; the detected three-dimensional angular orientation; and the corrected wind speed and direction data; and

detecting failures of the one or more instruments, and in response to the detection of a failure using the last valid orientation information to correct the wind speed and direction data.

21. The method of claim 20 in which the three-dimensional angular orientation is provided at least in part by a user who has overridden the instruments.

22. The method of claim 20 in which the three-dimensional angular orientation is provided by a user.