A low cost data logging system with satellite transmission capabilities

Abstract

The concept of updating a shore based data bank by regular satellite transmissions of data collected at sea has important uses in programmes on the exploration and survey of sea bed mineral sites. In this context, the need arose to log data from a satellite navigator, deep sea echosounder, and a magnetometer on board a chartered research vessel. A novel data logger design was implemented with the extra option of transmitting logged data through the ships INMARSAT approved satellite terminal. The logger consists of an expandable 8 bit processor card (developed in-house), and a versatile high density tape recorder. The interrupt driven software for the logger was written in PLM 85 - a Higher Level Language. The results show that useful geophysical data collected at sea can be received on a shore computer at 2400 baud with a negligible error rate. Furthermore, this development shows that in-house construction of essential hardware/software components based on specific user needs reduces cost, increases reliability, and permits functional expansion as and when required by the user