Skin Satellite Monitoring Answering Machine Ranging Accuracy

Pico-satellites are the import investigative domain in the modern aerospace technologies. Pico-satellites have advantages of high self-control degree, low weight (1kg or lighter), short R&D period and low expense. It has been a hotspot for many countries after nano-satellite. The Pico-satellites can combine satellite cluster, sharing the resource and information with each other. They can be used in three-dimensional imaging, distributed aerospace measure, scientific experimentation with lower cost. The Pico-satellites will play greatly important role in the military affairs, scientific research and commercial application with these advantages.This thesis mainly analyzes the design of the Pico-satellite TT&C transponder's system, which includes the functions of RF signal processing, BPSK demodulation and command recognition. By using this Pico-satellite TT&C transponder's system and new method of data processing, the function of range acquisition is come true and the precision of range acquisition is improved. Finally, the error source of range acquisition signal's jitter is analyzed.The works in this thesis are following:1. Based on analyzing the entire functions of integrated Pico-satellite TT&C transponder's system, the components of system power, RF signal processing, BPSK demodulation and command recognition are improved and integrated. The performance of integrated Pico-satellite TT&C transponder's system is better than the previous system.2. Range acquisition is an important function of satellite system. This thesis introduces the theory of side tone range acquisition and the equipments of range acquisition firstly. Then it analyzes the new method of measuring the phase difference of range acquisition signals by FPGA circuit. For improving the precision of range acquisition, this thesis also analyzes the feasibility of numerical value average's method and makes it achievement in DSP. The time and temperature's character experiments of range acquisition system also have been done. In long time, the rangeacquisition system presents stably. In different temperatures, the fixup phase difference of range acquisition signals which is imported from range acquisition system is changed regularly and the jitter of range acquisition signals is also changed. By analyzing the results of experiments, I have got the best environment temperature range.3. The phase error sources resulting in jitter of range acquisition signals has been analyzed. By analyzing the close-loop model in range acquisition system, I have obtained the transfer function of all kinds of phase noise sources and also found the main reason resulting in the jitter of range acquisition signals.4. Based on analyzing a new method of designing phase modulation with microstip, I simulate this new designing of phase modulation using ADS tools and test its practical performance. It is identical of these two results.An integrated Pico-satellite TT&C transponder's system has been designed successfully. The performance of this integrated system is better in following dimensions: The sensitivity is up to -92dBm; the emitting power is up to 20dBm; the precision of range acquisition is up to 5m. By analyzing the phase error source of range acquisition system, it makes sure that the noises of VCXO, VCO in nest-loop and input signal are the main reasons for the jitter of range acquisition signals.