No abstract

The manual retrieval of data from automated recorders is expensive and time consuming owing to the remote locations of many of the key data-collection stations.In the mid-1970's, the escalation of costs for data collection and a need for more timely data led the USGS Arizona District to begin examining alternatives for remote-data acquisition. On the basis of successful data-communications experiments with the National Aeronautic and Space Administration's (NASA) Landsat satellite, an operational system for satellite-data relay was developed in 1976 using the National Oceanic and Atmospheric Administration's (NOAA) Geostationary Operational Environmental Satellite (GOES). Satellite-telemetry operations are controlled at the gaging station by a small battery-operated datacollection platform (DCP).The DCP periodically collects data from sensors, stores the data in computer memory, and, at preset times, transmits the data through an internal radio to the GOES satellite. The satellite, which acts as a relay point, retransmits the data to a groundreceive station that transfers the data by land communications to the USGS computer for processing. A satellite relay transfers the data from sensor to computer in minutes versus the weeks and months required for manual retrieval and processing; therefore, the data are available to users on a near real-time basis.The network of stations supported by GOES satellite telemetry in Arizona was increased from 8 stations to 62 stations after major flooding in 1978-79. The major purpose of the network is to provide real-time river-stage data to the Arizona Flood Warning Office in Phoenix, which is operated jointly by the National Weather Service (NWS) and the Arizona Department of Water Resources (ADWR).In addition to the expansion of the telemetry system, procedures for handling data are changing from a centralized system located primarily in Reston, Virginia, to a distributive system in Arizona, Colorado, Washington, and several other States. This report describes the operation of the USGS satellite-telemetry system in Arizona, including the operations of DCP's, satellite-receive stations, and computerized data-handling procedures.The report also summarizes the performance, coordination, and management of the remote-telemetry system.