Shipboard Computers
Authors: Neitzel E.B. 
Published: October 2008

Computers for geophysical applications onboard ships have been in an evaluation phase for the last few years. Functions of (1) data collection operations control, (2) data quality control, (3) automatic logging of total system collection parameters, (4) signal enhancement, and (5) adaptive processing have been under evaluation. Although the functions of data logging and operations control are significant, a salient economic justification for the ship computer in the future will be adaptive processing. Adaptive processing to change the data collection system to improve signal to- noise ratio is a process that is sometimes not possible on a cost-effective basis within a large central computer. Onboard processing is illustrated by two applications -- time-varying deconvolution of seismic data and statistical combination of navigation sensors to improve positional accuracies. Total spectrum of geophysical data acquisition processing applications for the shipboard computer are grouped into categories.

INTRODUCTION

During the last decade, we have seen a rapid change in the evolution of electronic component technology. We have seen a transition in the fabrication of equipment systems from the vacuum tube to the transistor to the integrated circuit and to LSI (large-scale integration of integrated circuits). Within this total industry trend, automation in component fabrication has resulted in significant price reductions in components. These price reductions have made it possible for the computer manufacturer to provide cost-effective digital computers for many applications. Concurrent with this price decrease, the computer-design industry has experienced a phenomenal increase in electronics hardware reliability. While the price of the total computer system has remained relatively constant during the last few years, this stability has come about through two almost equal and opposing price trends. The cost of the central processing unit has decreased while the computer peripherals have increased. Industry currently finds itself in a position where the stored-program central processing unit (CPU) is cost-effective for many applications not envisioned a few years ago. Both the cost-effective factor and the reliability considerations will allow the general-purpose digital computer to be used for many applications onboard ship.

Use of computers onboard ships has a recent history. To deal with large volumes of tactical data, the Navy Tactical Data System was used in early 1961. From 1962 to the present, approximately sixteen general-purpose computers have been used at sea by the Oceanographic Institutes and various research agencies of the government. In addition, several of the major oil companies have used computers for integrated exploration systems. Primary functions for most small shipboard computers, associated with sensor data collection, are data formatting, data quality control, data annotation, and data reduction.

In addition to these functions, the computer is applied to certain highly specific problems. Processing of the Navy's navigation satellite data is receiving widespread attention at the present time. Within the near future, it is highly probable that the computer will be used on a time-shared basis for data acquisition control, data processing, position determination, and automatic ship control. Use of the computer to adaptively improve the signal-to-noise ratio for data acquisition systems is receiving application at the present time.