System and method for removing and reinstalling weapon sight without changing boresight

Abstract

A system and method for removing and reinstating a sight of a weapon without changing a boresight is disclosed. A reference optical device is installed on a rail of the weapon and then the sight is installed on the rail. An attitude determination unit determines a change in attitude of the sight with respect to the boresight. The aim point of the weapon in the sight is compensated accordingly based on the change in attitude without changing the boresight by utilizing a compensation module. This allows retaining the boresight even when the weapon sight is removed and reinstalled. Thus weapon sight can be mounted anywhere on a weapon without the need to boresight the weapon.

What is claimed is: 
     
         1 . A method for removing and reinstalling a sight of a weapon without changing a boresight comprising:
 installing a reference optical device on a rail of the weapon;   installing the sight on the rail;   determining a change in attitude of the sight with respect to the boresight; and   compensating the aim point of the weapon in the sight based on the change in attitude without changing the boresight.   
     
     
         2 . The method of  claim 1  further comprising accounting a change in attitude of the sight from a first position on the rail to a second position on the rail. 
     
     
         3 . The method of  claim 1  further comprising configuring the optical reference device at a fixed position on the rail at which the weapon sight is perfectly aligned with the boresight, whereby the weapon sight can be positioned at any position on the rail and by determining the change in the attitude of the weapon sight with respect to the optical reference, so that the weapon sight is adjusted without changing the boresight. 
     
     
         4 . The method of  claim 3  wherein the attitude data between the optical reference and the weapon could be is coded into a reference module and sent to the weapon sight when installed. 
     
     
         5 . A method for automatic alignment of a sight of a weapon with a boresight without changing the boresight comprising:
 installing a reference optical device on a rail of the weapon;   installing the sight on the rail;   allowing a light to reflect from the reference optical device and from an optical device in the sight;   obtaining a resultant light reflected from the reference optical device and from the optical device in the sight;   processing the resultant light;   determining a change in attitude of the sight relative the boresight; and   automatically adjusting the sight based on the change in attitude, whereby alignment is insensitive over time to shifts due to shock, vibration and temperature so that differential measurement provides temperature and vibration hardening.   
     
     
         6 . The method of  claim 5 , wherein the processing the resultant light comprising:
 adjusting the brightness of the resultant light;   performing dual centroid operation;   determining the azimuth and elevation offsets;   obtaining a change in attitude of the sight relative the boresight by subtracting the error obtained based on the offsets.   
     
     
         7 . The method of  claim 6 , wherein adjusting the brightness of the resultant light comprising:
 increasing the brightness of the maximum pixels of the resultant light to a first predetermined value; and   decreasing the brightness of all the pixels that are below a second predetermined of a saturation point.   
     
     
         8 . The method  claim 5  further comprising configuring the reference optical device at a fixed position on the rail at which the weapon sight is perfectly aligned with the boresight. 
     
     
         9 . The method of  claim 5 , wherein the reference optical device is maintained in the rail irrespective of removal and reinstallation of the sight of the weapon. 
     
     
         10 . A system for removing and reinstalling a sight of a weapon without changing a boresight comprising:
 a reference optical device installed on a rail of the weapon;   the sight installed on the rail;   an attitude determination unit for determining a change in attitude of the sight with respect to the boresight; and   a compensation module for compensating an aim point of the weapon in the sight based on the change in attitude without changing the boresight.   
     
     
         11 . The system of  claim 10  wherein the attitude determination unit accounts the change in attitude of the sight from a first position on the rail to a second position on the rail. 
     
     
         12 . The system of  claim 10  further comprising an automatic alignment unit for aligning the sight of the weapon with the boresight without changing a boresight. 
     
     
         13 . The system of  claim 12  wherein the automatic alignment unit is configured to:
 allow a light to reflect from the reference optical device and from an optical device in the sight; 
 obtain a resultant light reflected from the reference optical device and from the optical device in the sight; 
 process the resultant light; 
 determine a change in attitude of the sight relative the boresight; and 
 adjust the sight based on the change in attitude. 
 
     
     
         14 . The system of  claim 13  wherein the resultant light is processed to:
 adjust the brightness of the resultant light; 
 perform dual centroid operation; 
 determine the azimuth and elevation offsets; 
 obtain a change in attitude of the sight relative the boresight by subtracting the error obtained based on the offsets. 
 
     
     
         15 . The system of  claim 14  wherein the brightness of the resultant light is adjusted by:
 increasing the brightness of the maximum pixels of resultant light to a first predetermined value; and 
 decreasing the brightness of all the pixels that are below a second predetermined of a saturation point. 
 
     
     
         16 . The system of  claim 14 , wherein the reference optical device is maintained in the rail irrespective of removal and reinstallation of the sight of the weapon. 
     
     
         17 . The system of  claim 14 , wherein the reference optical device is fixed at a position on the rail at which the weapon sight is perfectly aligned with the boresight.