Polarization grating based star simulator

A star map projection system consisting of:

• a laser that emits a laser beam;
• a polarization grating that spatially reduces the laser beam to a reduced laser beam;
• an attenuator that attenuates the reduced laser beam to form an attenuated laser beam;
• a first Risley element in a first holder that deflects the reduced laser beam to form a first angled laser beam, the first holder providing independent rotation of the first Risley element;
• a second Risley element in a second holder that receives the first angled laser beam and forms a second angled laser beam which is directed onto a screen, the second holder providing independent rotation of the second Risley element;
• a controller that independently rotates each Risley element to position the simulated star laser beam onto a pre-defined location on the screen;
• a pair of rotation actuators in communication with the controller through a device interface that are respectively engaged to the first and second holders for rotation of the Risley elements, the controller comprising
• a memory containing an application and a lookup table, wherein the controller comprises a processor that executes the application to:
• monitor current rotation positions respectively of the first and second Risley elements reported by the first and second rotation actuators;
• determine a pre-defined location on the screen;
• determine a change in rotation positions of the first and second Risley elements specified in the lookup table based on current rotation positions and a two-dimensional position of the second angled laser beam;
• and
• actuate the first and second rotation actuators to effect a change in the rotation positions of the first and second Risley elements.