From Telemark to Internet

Neil Chapman - WA Dept of Water , 22 October, 2010

Prior to the eighties telemetry on W.A. gauging station’s was limited to 5 Telemark installations. Widespread telemetry started with the introduction of data loggers in the late eighties. Currently Department of Water (DoW) operates 362 gauging station’s with 154 connected for dial-up telemetry using either GSM, 3G, Satellite (Inmarsat and Iridium), radio or landline delivery services. Dial-up telemetry has for the most part been successful despite the fact of having so many systems that are complex from both an operational and technical support viewpoint. This complexity has been an ongoing issue and Internet Protocol (IP) telemetry offers an opportunity to reduce these systems to just two; 3G and Satellite.

In the DoW, instrument support comes through a specialist group based in Welshpool. The facility known as Hydrologic Technology Centre (HTC) consists of 8 staff and has been in existence since the sixties. The HTC has been monitoring the development of IP telemetry since 2001 and embarked on a trial on this technology in 2008. The trial recently concluded and led to a decision to convert all existing dial-up systems. By converting to IP telemetry the number of systems will reduce, call costs will reduce plus users will have access to near real time data. The two greatest obstacles to telemetry on all sites for the department have been either lack of service coverage or lack of funds. Although Low Earth Orbit (LEO) satellite communication systems remedy the coverage aspect, call costs are cheaper than dial-up and although high setup costs are partially offset by BoM funds the ongoing monthly costs still remain an obstacle for total telemetry coverage.

It is no surprise the history of telemetry at DoW gauging station’s follows changes imposed by the telecommunications industry. Systems changed from Public Switched Telephone Network (PSTN ) to Analog or Advanced Mobile Phone System (AMPS, 1G) to Global System for Mobile Communications (GSM, 2G) and Code Division Multiple Access (CDMA) to today’s Universal Mobile Telecommunications System (UMTS, 3G). Advances in computing systems, satellite technology and the internet have all influenced telemetry systems. Hydrographer’s today are expected to be knowledgeable in all of these facets. It is the hydrographer’s lot to adopt and adapt off the shelf technologies designed for mass markets to gauging station operations.