| Synthetic aperture radar (SAR) is an active microwave remote sensor, which has the high azimuth resolution by using the theorem of synthetic aperture. Because of its widely application in military and civilian Synthetic Aperture Radar has received more and more recognition. SAR develops rapidly in recent years, the data acquisition and storing system, as the important part of SAR system, was requested the more and more high working performance. Some data recording system cannot suit the higher requirement any more.In SAR system, the in-phase and quadrate echoes must be sampled simultaneity and stored for a long-time. Because of the limitation of hardware, only the available echoes can be stored. The receiver must detect the position of available echoes in bi- and multistatic SAR. In this paper, a method to detect the position of available echoes in the integrity PRI was present. A high-speed data acquisition and storing system, which is based on SATA disks and used in SAR, is introduced in this dissertation. FPGA is used to control the system's working time. The SMT387 module changes the data's format into which is applicable in FAT32 file system, and it will finish the SATA disk's controlling. The character of this system is that the data is stored in FAT32 file system, which is generally used in computers nowadays and makes the recorded data can be easily read and processed by computers. The SATA disk whose average recording speed arrives at 40 MB/s is chosen to be storage, and the data communication between different PCBs is finished by SHB whose speed is 240 MB/s.The primary work in this dissertation:A method was present to detect the radar echoes by slide-window. The calculation of gate, which was based on CFAR, was present and proved both by theory and experiment result.The system's construction and design proposal was introduced form every part of itThe central controlling and system working flow was completed, the controlling of SHB bus was realized. |
PDF Full Text Request