| Summary: | Accurate tracking system is a mandatory in the development of rocket technology.
LAPAN has developed a prototype of secondary RADAR using UHF radio. Rocket is loaded with
transponder, while a receiver is placed in the observatory station. The distance is calculated
based on Time Different of Arrival TDOA between transmitted signal and received back at the
earth station.
This research is to develop an algoritm for distance determination using time based
correlation (Cross Correlation) and frequency based correlation (Generalized Cross
Correlation). Simulation has been done to noiseless signal and signal with random noise. The
signal with random noise is first simulated without filter and the second simulated with bandpass
filtr. A simulation is also done to determine the effect of sub carrier frequency 2500 Hz, 5000 Hz,
10000Hz and 12500Hz. Calibration and experiment on Rocket Rx100 has been done.
Experiment with random noise still indicates readable signal with measurement error
less than 5% with SNR = 0.1667 for time based TDOA algorithm, and SNR = 0.2 for Frequency
based TDOA algorithm. After passed through a bandpass filter the error is less than 1% with
SNR 0.25 both for time based TDOA algorithm, and for Frequency based TDOA algorithm. The
higher sub carrier frequency used, indicates lower error, therefore measurement error less than
5% resulted with sub carrier frequency at 12500 Hz
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