Laser spot tracking receiver

A system for tracking at least one object being illuminated by a laser designator, the system being configured for use in conjunction with an optical apparatus configured for receiving a light beam scattered by the at least one object in response to illumination from the laser designator, the system comprising:

• a detector having a sensing surface divided into exactly three sectors, each sector being adjacent to two sectors and all sectors meeting at a central point, the sensing surface of the detector being positioned with respect to the optical apparatus such that the light beam is projected by the optical apparatus onto the sensing surface as an unfocused spot, and each sector being configured for generating a respective signal indicative of an energy of a portion of the spot illuminating the sector;
• a data processing apparatus configured for receiving the signals from the detector, and processing the signals to determine an orientation of the system with respect to the at least one target;
• wherein the data processing apparatus comprises a processing unit and is associated with a non-volatile memory unit, wherein:
• the processing unit is configured for (i) receiving the signals from the sectors, (ii) determining a sum of the signals, (iii) determining exactly three ratios, each ratio corresponding to a respective sector and being calculated by dividing a signal from the respective sector by the sum of the signals, and (iv) determining the orientation of the system with respect to the at least one target based on the three ratios;
• the non-volatile memory unit is configured for storing at least one of:
• a look-up table wherein a set of the three ratios leads to a unique value indicative of the orientation of the system with respect to the at least one target;
• and
• an algorithm configured for enabling the processing unit to calculate the orientation of the system with respect to the at least one target based on the ratios.

A method for tracking at least one target being illuminated by a laser designator, the method comprising:

• receiving signal outputs from sectors of a detector illuminated by a light beam scattered from the target in response to target being illuminated by the designator, the detector being divided into exactly three sectors, each sector being adjacent to two sectors and all sectors meeting at a common point, the signal outputs being indicative of respective energies of the portions of the light beam illuminating the respective sectors of the detector;
• determining a sum of the signals;
• determining a plurality of ratios, each ratio corresponding to a respective sector and being calculated by dividing a signal from the respective sector by the sum of the signals;
• and
• determining the orientation of the system with respect to the at least one target based on the three ratios, via a look-up table and/or via one or more algorithms.