CLOCK REQUIREMENTS FOR NAVIGATION, COMMUNICATION AND IDENTIFICATION SYSTEMS

Abstract
This paper describes the application of precision frequency standards as the time base in navigation, communication and identification systems. Because these systems are placed in several different types of platforms, the frequency standard must be selected on the basis of compatibility with the weight, volume and power supply constraints exerted by the overall system configuration. Furthermore, the operational environment places additional control on the oscillator specifications which relate to sensitivity to changes of temperature and pressure, to vibration, and in certain cases, to exposure to radiation. Some examples of how the application governs the choice of the oscillator are given as well as a review of new technology developments which promise improvements in both performance characteristics and acquisition costs.