Ampex 200, seven channel, magnetic tape recorder is used
to record all necessary data at a rate of five (5) times
per second. Unique features of Shiran are its calibration
built-in test, and four station ranging capability. Cali
bration of the airborne subsystem can be accomplished by
simply pressing a calibrate button. The subsystem,
utilizing a built-in test oscillator, measures the phase
delay and places it in memory. This phase delay is auto
matically subtracted from each subsequent range measure
ment. System calibration is accomplished within ten (10)
seconds. Calibration can also be checked at any time to
guard against drift. Additional built-in test features
have been incorporated that allow for check-out of the
system while airborne. Malfunctions in the system can be
detected and pinpointed. By use of a maintenance adapter,
the system can be repaired. These built-in test features
were used exclusively during the flight test and proved
out well. Because of these features, no test support
equipment was required at the flight test site. The most
important feature of the Shiran system is its four station
ranging capability. This feature gives the system flexi
bility, increases its reliability, and enables the perfor
mance of controlled photography missions that become most
difficult with any two channel system.