Method and apparatus for alignment harmonization

Abstract

Techniques and architecture are disclosed for performing alignment harmonization of a collection of electro-optical and/or gimbaled componentry that is to operate within a common coordinate frame. In some cases, the techniques and architecture can provide a cost- and time-efficient approach to achieving alignment harmonization that is compatible, for example, with field-test and/or operational environments. In some instances, the techniques and architecture can be used in concert with, error calibration techniques to further improve the accuracy of the alignment harmonization. The techniques and architecture can be utilized with a wide range of components (e.g., sensors, armaments, targeting systems, weapons systems, countermeasure systems, navigational systems, surveillance systems, etc.) on a wide variety of platforms. Numerous configurations and variations will be apparent in light of this disclosure.

What is claimed is: 
     
         1 . A method of performing alignment harmonization, the method comprising:
 operatively coupling an inertial measurement unit (IMU) with a common reference surface of a platform and beginning collection of a first set of angular rate data;   uncoupling the IMU from the common reference surface and transitioning the IMU to a reference surface of a unit under alignment (UUA); and   operatively coupling the IMU with the UUA reference surface and stopping collection of the first set of angular rate data.   
     
     
         2 . The method of  claim 1  further comprising using the first set of angular rate data to determine a difference in attitude between the common reference surface and the UUA reference surface. 
     
     
         3 . The method of  claim 2 , wherein after operatively coupling the IMU with the UUA reference surface and stopping collection of the first set of angular rate data, the method further comprises:
 uncoupling the IMU from the UUA reference surface, operatively coupling the IMU with the common reference surface, and beginning collection of a second set of angular rate data;   uncoupling the IMU from the common reference surface and transitioning the IMU to a reference surface of a second UUA; and   operatively coupling the IMU with the reference surface of the second UUA and stopping collection of the second set of angular rate data.   
     
     
         4 . The method of  claim 3  further comprising using the second set of angular rate data output by the IMU to determine a difference in attitude between the common reference surface and the reference surface of the second UUA. 
     
     
         5 . The method of  claim 1 , wherein the common reference surface and the UUA reference surface operate within a common coordinate frame. 
     
     
         6 . The method of  claim 1 , wherein before operatively coupling the IMU with the common reference surface of the platform, the method former comprises calibrating the IMU. 
     
     
         7 . The method of  claim 6 , wherein calibrating the IMU comprises:
 determining a latitude and attitude of the common reference surface of the platform, a heading of the common reference surface with respect to true north, and gravitational direction;   operatively coupling the IMU with the common reference surface for a period of time to capture angular rate error data; and   uncoupling the IMU from the common reference surface, rotating the IMU, and recoupling the IMU with the common reference surface to capture rate scale factor error data.   
     
     
         8 . The method of  claim 7 , wherein the angular rate error data is used to improve alignment harmonization. 
     
     
         9 . The method of  claim 1 , wherein the rate scale factor error data is used to improve alignment harmonization.