Radiation tracking apparatus with pulse counters for producing output indicative of pointing error

Claim 1

A RADIATION TRACKING DEVICE COMPRISING: IMAGE FORMING MEANS; A RETICLE HAVING A PLURALITY OF ALTERNATE TRANSPARENT AND OPAQUE PORTIONS ARRANGED IN A CIRCULAR PATTERN; MEANS FOR CAUSING MOVEMENT OF THE IMAGE OF SAID IMAGE FORMING MEANS AT A SUBSTANTIALLY CONSTANT SPEED IN A CIRCLE ACROSS SAID PORTIONS OF SAID RETICLE; RADIATION DETECTING MEANS MOUNTED IN ALIGNMENT WITH SAID RETICLE SO AS TO RECEIVE RADIATION PASSING THERETHROUGH, SAID RADIATION DETECTING MEANS INDICATING THE APPROXIMATE POSITION OF THE IMAGE WITH RESEPCT TO SAID RETICLE; RELATIVELY HIGH FREQUENCY PULSE PRODUCING MEANS; FIRST AND SECOND REVERSIBLE COUNTING MEANS; MEANS CONNECTING SAID RADIATION DETECTING MEANS TO SID FIRST AND SECOND COUNTING MEANS FOR ACTUATING, REVERSING AND STOPPING SAID FIRST AND SECOND COUNTING MEANS UPON THE IMAGE REACHING PREDETERMINED POSITIONS WITH RESPECT TO SAID RETICLE; AND MEANS CONNECTING SAID FIRST AND SECOND COUNTING MEANS TO SAID PULSE PRODUCING MEANS; SAID FIRST COUNTING MEANS PRODUCING A DIGITAL OUTPUT INDICATIVE OF THE DISTANCE OF A RADIATION SOURCE FROM THE CENTER OF THE FIELD OF VIEW OF SAID IMAGE FORMING MEANS ALONG A FIRST AXIS AND SAID SECOND COUNTING MEANS PRODUCING A DIGITAL OUTPUT INDICATIVE OF THE DISTANCE OF THE RADIATION SOURCE FROM THE CENTER OF THE FIELD OF VIEW OF SAID IMAGE FORMING MEANS ALONG A SECOND AXIS.