USGS Frequently Asked Questions

Answer:

Data from many real-time streamflow gages are relayed to USGS offices through the Geostationary Operational Environmental Satellite (GOES) data-collection system or by telephone. Data are transmitted from each station at intervals of 4 hours and are loaded onto the computer system. This 4-hour interval is based on a transmission time window available for the satellite and is not controlled by USGS.

Data from other stations is obtained through an automatic telephone dial-up, and the computer is set to call on a 4-hour interval. USGS does control this system, but it is limited by the actual time that it takes to dial and download data.

USGS is investigating alternative systems to provide data on a more frequent basis during floods. However, because most existing real-time streamflow gages are located on larger rivers and the hydrologic response time of these rivers is generally much greater than 4 hours, the current system is adequate for most applications.