Ship System 2000
Real-time computing is a term that seems easy enough to understand, but that eludes most attempts at strict definition. The Ship System 2000 family of naval Command, Control, Communications and Weapon Control systems does, however, encompass most variants of computer programming that fall under the real-time heading. Towards the soft end, the systems are expected to handle large amounts of data and provide decision support tools that are used to analyze tactical scenarios a number of hours into the future. There, response time is not extremely critical, but size and algorithmic performance issues can nevertheless be crucial. In the middle of the spectrum, data fusion and display functions (for instance), should have response times compatible with human reaction times. Approaching the area of hard real-time programming, we have servo loops in, e.g., the fire control system running at more than 50 Hz. The extreme cases are also present: signal processing in the radars themselves, running at several kHz.