Horizon sensor for satellite attitude control

Claim 1

A SCANNING SYSTEM FOR USE IN THE CONTROL OF THE ATTITUDE OF A SPACE-TRAVELLING DEVICE COMPRISING: A FIRST SCANNING MEANS INCLUDING A RADIANT ENERGY COLLECTOR FOR SCANNING INDEPENDENTLY OF THE MOTION OF SAID DEVICE AND WITH A PREDETERMINED SCANNING AMPLITUDE THE HORIZON OF A BODY WITH RESPECT TO WHICH A CONTROL IS TO BE ESTABLISHED TO RECEIVE ENERGY AT DIFFERENT TIMES DURING SAID SCAN FROM A RELATIVELY SMALL PORTION OF SAID BODY AND A CORRESPONDINGLY SMALL PORTION OF SPACE ADJACENT SAID BODY; A SECOND SCANNING MEANS INCLUDING A RADIANT ENERGY COLLECTOR HAVING A SCANNING DIRECTION WHICH IS FIXED WITH RELATION TO THAT OF SAID FIRST SCANNING MEANS FOR SCANNING INDEPENDENTLY OF THE MOTION OF SAID DEVICE AND WITH A PREDETERMINED SCANNING AMPLITUDE SUBSTANTIALLY EQUAL TO THAT OF SAID FIRST SCANNING MEANS A DIFFERENT PORTION OF THE HORIZON OF SAID BODY TO RECEIVE ENERGY AT DIFFERENT TIMES DURING SAID SCAN OF SAID SECOND SCANNING MEANS FROM A RELATIVELY SMALL PORTION OF SAID BODY AND A CORRESPONDINGLY SMALL PORTION OF SPACE ADJACENT SAID BODY; MEANS FOR SIMULTANEOUSLY OPERATING SAID FIRST SCANNING MEANS AND SAID SECOND SCANNING MEANS; MEANS RESPONSIVE TO THE TIME RELATIONSHIP BETWEEN THE SIMULTANEOUS RECEIPT BY SAID FIRST SCANNING MEANS OF ENERGY FROM SAID BODY AND FROM SPACE AND THE SIMULTANEOUS RECEIPT BY SAID SECOND SCANNING MEANS OF ENERGY FROM SAID BODY AND FROM SPACE FOR OPERATING MEANS TO CONTROL THE ATTITUDE OF SAID DEVICE; AND MEANS RESPONSIVE TO THE RATIO OF THE PERIODS WHICH AT LEAST ONE OF SAID SCANNING MEANS IS SCANNING ENERGY FROM SAID BODY AND FROM SPACE IN ITS SCANNING CYCLE FOR REDUCING THE AMPLITUDE OF SCAN IN ITS SCANNING SCANNING MEANS TO A SMALL PORTION OF SAID PREDETERMINED SCANNING AMPLITUDE WHICH INCLUDES THE POSITIONS OF EACH AT WHICH ENERGY IS SIMULTANEOUSLY RECEIVED FROM SAID BODY AND FROM SPACE.