Transmission of digital data

The Geological Survey, Water Resources Division, established a pilot project to evaluate equipment that would transmit date recorded on 16-channel paper tapes over voice-grade telephone lines from field offices to the Washington, D.C., Automatic Data Processing Unit (A.D.P. Unit). Such equipment would allow computer-processed data for current-purpose hydrologic data stations to be made available in a more timely manner. The specifications for the equipment were prepared in March 1970; invitations to bid were solicited, a contract was awarded and the equipment was delivered in November 1970. The equipment included two reader/transmitter units, and one receiver/recorder unit.

The reader/transmitter units transmit manually entered fixed information, i.e. station number, beginning date and time, and ending date and time, and photoelectrically read and transmit the 16-channel paper tape data. The receiver/recorder unit records the transmitted information on IBM-compatible magnetic tape.

This report summarizes the information gained from a year of pilot operation of the equipment, with and without a computer terminal at the field level, and makes recommendations for establishing a data-transmission system in the Water Resources Division.