Data Collection Problems in Second Generation Ballistic Missiles

This paper deals with the problem of airborne data collection from advanced ballistic missiles, sometimes called second generation ballistic missiles. Because of improvements in warhead technology, these advanced missiles have a much smaller warhead compartment than previous missiles of the same class. The airborne data collection system has on many previous R&D missiles normally occupied part or all of the warhead space. It becomes obvious therefore, that with a smaller and lighter warhead, more severe weight and space limitations on the airborne instrumentation will tend to exist than heretofore. Analysis of data requirements reveals that the reduction in the quantity and the complexity of measurements for solid propellant systems over that required on liquid propellant systems is not as great as one might easily assume. Data collection problems for the guidance and control system involve the transmission at a high repetition rate of pulse or digital data of extreme accuracy. Problem areas exist with analog to digital and digital to digital converters for use in monitoring and totalizing angular shaft motions associated with the guidance systems. Problems are also present with the encoding of serial pulse trains for transmission over existing telemetry systems. Proposed means for handling some of the pulse data collection problems are presented. A fundamental principle for use in the design of an airborne data acquisition system can be stated as follows: ``The nature and amount of the data to be collected should be a major determining factor of the overall system design.