ALTITUDE INFORMATION AND TACTICAL AIR NAVIGATION
JAMES A. SCHMITENDORF · 1962
An altitude encoder for the aircraft owner who can least afford the complicated equipment used by the military and airlines is discussed. Also considered is a method of transmitting the encoded altitude to ground controllers by means of superimposing altitude information with distance measuring interrogation signals. A mercury manometer was demonstrated to be feasible for encoding but it was not practical due to its large size. The standard aneroid altimeter was shown to be both feasible and practical as modified to serve an additional function as an encoder. A Kollsman altimeter was modified for optical altitude encoding at a cost of approximately $50. A digital logic circuit was devised for transferring the altitude information to a military Tactical Air Navigation transmitter and the transmitter was modified to send out altitude information while retaining its normal distance measuring interrogation function. Distance Measuring Equipment (DME) was chosen as a transmission media.