Design Of Control Software For Commercial Miniaturized Multi-mode GNSS Occultation Receiver

With the development of the Global Navigation Satellite System(GNSS),its use is no longer limited to positioning and navigation.GNSS occultation observation remote sensing technology can provide globalized,all-weather,high vertical resolution atmospheric profile information,and has a wide range of applications in meteorology,astronomy,etc.With the rise of commercial aerospace,commercial occultation detection has become a hot topic in GNSS remote sensing.Commercialization means that the receiver has the characteristics of short design cycle,low cost,small device size,and support for subsequent updates.Commercial miniaturized receivers use mature commercial-grade hardware platforms,and signal processing and software control systems are its core technologies.Based on the traditional GNSS occultation receiver design,this paper carries out an innovative design and realizes a control software system for a commercial miniaturized multi-mode GNSS occultation receiver based on the ZYNQ 7020 chip.This article first introduces the background of commercial occultation detection and the current research status at home and abroad.Then,starting from the development of GNSS,the basic theory of GNSS occultation detection is described,the composition of GNSS occultation detection system is explained,and the commercial miniaturized multi-mode GNSS is explained.Advantages of occultation receivers.Secondly,the overall design of a commercial miniaturized multi-mode GNSS receiver is introduced,and its control software is modularized.Among them,the positioning module realizes the positioning calculation of the receiver;the occultation module realizes the functions of occultation prediction and occultation tracking;the data module realizes the receiver data transmission and command reception,and transmits the occultation observation data to the ground for subsequent calculation.In addition,a new pilot + data modulation method is proposed for major GNSS systems.According to its carrier phase relationship,this paper proposes a joint open-loop tracking algorithm for pilot components and data components based on the traditional open-loop tracking method.Compared with the traditional method,this method can improve the signal carrier-to-noise ratio,improve the carrier phase tracking accuracy,improve the stability of the tracking,and provide more accurate data for the inversion calculation without changing the hardware circuit.Finally,on the basis of the above design,the receiver designed in this paper is simulated on-orbit for preliminary verification.During the experiment,all functions and accuracy indicators of the equipment can be achieved.The proposed joint open-loop tracking method can obtain higher observations.The signal strength and open-loop carrier phase observation accuracy prove the correctness of the receiver's overall design and provide reliable technical support for subsequent on-orbit operations.