Research On Radar Image Acquisition Card Based On Wavelet Transform

With the development of science and technology,equipment used for maritime traffic and transportation has been updated continually.VDR(Voyage Data Recorder) is a device which can record ship real time voyage data and replay the data.With the data we can replay the whole environment around the vessel if we wanted.As one of the most important part of VDR,radar image acquisition card can record all information appeared on Radar Display.It records a large number of image information,but the VDR storage capacity is limited,so we need to compress the image information by the premise of ensuring the quality of replay.The study subject of the paper is the radar acquisition compression system in the Voyage Data Recorder.Design and implementation of wavelet transform based on the radar image acquisition system,at the same time on the image compression encoding the key technologies are studied.And SPIHT image compression algorithm is used.The advantage is after the end of zero-tree coding, even without entropy coding(such as arithmetic coding) is also able to obtain a higher compression ratio,and the EBCOT algorithm,compression ratio is almost similar,but the compression is fast and simple algorithm.This article first introduced the topic research background and the significance,and then introduced the element theory of wavelet transform.The hardware design of radar image acquisition card was given,including chips' selecting and communication method between chips.The paper also expounded image compression algorithm based on wavelet and gave out the method of image compression coding.Finally,this article introduced the development of software systems,including PCI driver and software design and implementation of radar card.The radar image gathering system has the good application prospect.