RADIOISOTOPE ALTIMETER Russian patent published in 1998 - IPC

FIELD: instrumentation engineering, navigation systems of spacecraft to form actuating signal for start of soft landing engines of landing modules of spacecraft. SUBSTANCE: given radioisotope altimeter has radioisotope radiation unit ( transmitter ), scintillation detector with reference source recording backward scattered gamma radiation from underlying surface and photodetector, frequency signal converter, dynamic error compensator connected in series, actuator and stabilizer which output is connected to second input of photodetector which first input is coupled to output scintillation detector. Stabilizer incorporates two comparators with reference signals, two diode intensitometers with metering vessels differing in value by factor of two and subtraction circuit forming stabilization signal. Altimeter is additionally inserted with device compensating change of activity of radiation source and background composed of former of initial delay, meter of signal of reference source, calculator of compensation signal of change of activity of radiation source, interval former, former of signal of background compensation, output former connected in series and buffer register. Input of register is connected to second output of calculator of compensation signal of change of activity of radiation source and its output is linked with input of code-controlled frequency divider. Its second input is connected to output of photodetector and its output - to second input of former of signal of background compensation and to input of converter of frequency signal. Second input of converter is connected to output of output former and output is connected to input of compensator of dynamic error ( corrector ) which output is coupled with input of actuator to which second input reference signal is fed. EFFECT: enhanced stability and reliability of altimeter. 4 dwg