Network

Claim 1

IN AN AIRCRAFT, MEANS TO DEVELOP SIGNALS REPRESENTING THE VELOCITY VECTOR OF THE AIRCRAFT IN SPACE, A SELF-CONTAINED NAVIGATION SYSTEM, SAID SELF-CONTAINED SYSTEM INCLUDING SIGNAL COMBINING MEANS TO RECEIVE THE VELOCITY VECTOR SIGNALS, FIRST INTEGRATOR MEANS COUPLED TO SAID SIGNAL COMBINING MEANS, MEANS TO COMBINE THE SIGNALS FROM SAID FIRST INTEGRATOR MEANS WITH SIGNALS REPRESENTING THE INITIAL POSITION OF THE AIRCRAFT TO DEVELOP SIGNALS REPRESENTING ITS PRESENT POSITION, SAID SELF-CONTAINED SYSTEM HAVING INHERENT LIMITATIONS WHICH DETERMINE MAXIMUM LIKELY POSITIONAL ERROR LIMITS FOR THE POSITION SIGNALS, A SOURCE OF EXTERNALLY-REFERENCED RADIO SIGNALS REPRESENTING THE POSITION OF THE AIRCRAFT RELATIVE TO A GROUND SITE, THE RADIO SIGNALS HAVING ERROR MAGNITUDES BETWEEN SAID ERROR LIMITS AND INCLUDING UNDESIRED RANDOM DATA AND VALID POSITION INDICATING DATA HAVING CONSTANCY, AND A STATISTICAL DATA PROCESSING SYSTEM FOR AUTOMATICALLY BRINGING THE POSITION SIGNALS AND THE VALID POSITION INDICATING DATA OF THE RADIO SIGNALS INTO AGREEMENT COMPRISING MEANS TO DEVELOP ERROR SIGNALS REPRESENTING THE DIFFERENCE IN MAGNITUDE BETWEEN THE POSITION SIGNALS AND RADIO SIGNALS, FUNCTION WEIGHING MEANS COUPLED TO SAID ERROR SIGNAL DEVELOPING MEANS, SAID FUNCTION-WEIGHTING MEANS COMPRISING A LINEAR AMPLIFIER AND A VARIABLE GAIN AMPLIFIER, MEANS TO APPLY A SIGNAL TO BOTH AMPLIFIERS, A SUBTRACTION NETWORK COUPLED TO THE OUTPUT OF SAID AMPLIFIERS, AN OUTPUT CIRCUIT TO RECEIVE THE OUTPUT OF SAID SUBTRACTION NETWORK, SWITCH MEANS COUPLING SAID OUTPUT CIRCUIT TO SAID SUBTRACTION NETWORK, GAIN CONTROL MEANS FOR SAID LINEAR AMPLIFIER, MEANS TO CONTROL SAID SWITCH MEANS COUPLED TO THE OUTPUT OF SAID LINEAR AMPLIFIER AND TO SAID GAIN CONTROL MEANS, SAID SWITCH CONTROL MEANS BEING OPERATIVE WHEN THE OUTPUT OF SAID LINEAR AMPLIFIER EXCEEDS A PREDETERMINED LEVEL TO OPEN SAID SWITCH MEANS AND CAUSE SAID GAIN CONTROL MEANS TO INCREASE THE GAIN OF SAID LINEAR AMPLIFIER TO CLOSE SAID SWITCH, SECOND INTEGRATOR MEANS COUPLED BETWEEN SAID FUNCTION WEIGHTING MEANS AND THE SIGNAL COMBINING MEANS, THEREBY TO PROVIDE A CLOSED DOUBLE-INTEGRATOR LOOP, SAID FUNCTION WEIGHTING MEANS RESPONDING TO THE ERROR SIGNALS TO DEVELOP OUTPUT SIGNALS REPRESENTING A PROBABILITY-WEIGHTED ERROR FOR THE SPECIFIC ERROR MAGNITUDE OF EACH OF THE RADIO SIGNALS BETWEEN SAID ERROR LIMITS, SAID SECOND INTEGRATOR MEANS DEVELOPING CORRECTION SIGNALS IN RESPONSE TO SAID OUTPUT SIGNALS, SAID FIRST INTEGRATOR MEANS INTEGRATING SAID CORRECTION SIGNALS WITH THE VELOCITY VECTOR SIGNALS TO CAUSE THE DIFFERENCE BETWEEN THE POSITION SIGNALS AND THE RADIO SIGNALS TO CONVERGE TO ZERO AND THEREBY PROVIDE CORRECTED POSITION SIGNALS REPRESENTING THE VELOCITY VECTOR OF THE AIRCRAFT RELATIVE TO GROUND, AND SAID FIRST AND SECOND INTEGRATOR MEANS PROVIDING LONG-TIME INTEGRATION SO AS TO BE SUBSTANTIALLY UNRESPONSIVE TO THE RANDOM DATA OF THE RADIO SIGNALS, WHEREBY SUBSTANTIALLY ONLY THE VALID POSITION INDICATING PORTIONS OF THE RADIO SIGNALS HAVING CONSTANCY ARE UTILIZED TO DERIVE SAID CORRECTION SIGNALS, AND WHEREBY TO PREVENT ACCEPTANCE OF RADIO SIGNALS CONSISTING SUBSTANTIALLY ENTIRELY OF UNDESIRED RANDOM DATA.