Rancang Bangun Sistem Pengukur Curah Hujan Jarak-Jauh Real Time Sebagai Peringatan Banjir Lahar Dingin

Abstract

The aim of this research is to set up a sufficient system, which is used for real-time rain
gauge telemonitoring as the early warning system for cold lava avalanche of Mount Merapi.
The system contains a remote station (transducer, Counter Timer, CPM Frequency Converter,
FSK Modulator, and Tx/Rx) and a controller station (Tx/Rx, FSK demodulator, and personal
computer).
Data managements which are developed in this research are expected to be used in a real
time a rain gauge telemonitoring of Mount Merapi. The characteristics of data communication
in this system are unguided type with air as the media, asynchronous serial mode, simplex mode
transmission, with audio modulation and frequency shift keying modulation. A pair of handy-
transceiver was use in data transmitting with VHF/UHF wave at Amateur Radio Data
Frequency (144,100 MHz and 431,125 MHz). Rainfall data changes 60 ml in 10 seconds was
sent with the variation of sound frequency, started at 645 Hz with delay time 0.0168 seconds up
to 2.993 Hz with delay time 0,0015 seconds.
This research is expected to give valuable information for the telemonitoring system
engineering development, especially for engineers who work in the field of telemonitoring
system and for the people who live in the Mount Merapi surrounding
Keywords: telemonitoring, rain gauge, FSK, modulation