The existing radar terminal system is implemented by a large number of high-speed dedicated chips. The replacement of the chip is very fast, many chips have been eliminated, even if it has not completely disappeared, the price is already very expensive, which brings great inconvenience to the maintenance and upgrade of the system. With the continuous development of computer, software and network technology, the software and network realization of a new generation of radar terminal systems is made possible. Based on this technical background, this paper studies and gives a concrete implementation of the system.
1 overall implementation
1.1 Based on Linux operating system
The traditional radar display system is based on Windows. But Windows faces many problems, such as closed source, easy to be infected by viruses and hackers. Linux is a free, open source, networked operating system. Its core is independent and highly configurable. Linux has better network features and security than Windows. So Linux-based system solutions are more appropriate.
1.2 System Implementation Plan
The system consists of a preprocessor, a main display machine and a network display machine, as shown in Figure 1.
The main functions of the preprocessor are: acquisition, compression and transmission of radar video, reception of secondary information and manipulation information and storage of all information. Main display function: Receive, decompress, display, receive secondary information and display, and man-machine control operation, send secondary information and control information to the network. The screen display machine is similar to the main display machine, but has no control function. For the sake of simplicity, this article does not discuss the implementation of the screen display machine.
2 implementation of the preprocessor system
The preprocessor completes the data acquisition, compression and transmission. The following three aspects are introduced.
2.1 PCI-based radar video capture card
This is the only hardware implementation part of the system and is essential to pass the collected data to the computer. The specific implementation of this part can be referred to the literature [1].
2.2 Wavelet compression technology
When the radar sampling rate is high, the network does not compress before transmission, and the bandwidth is not enough.
Frame-based compression techniques are not suitable for real-time requirements for radar video because a fixed delay is introduced. One-dimensional wavelet compression can achieve a compromise between efficient compression and real-time requirements.
The idea of ​​wavelet compression is to divide the one-dimensional digital sequence into two parts: coarse scale and detail, each occupying half of the storage space. This process can be recursively; because the echo signal is relatively smooth, the detail part is mainly noise, so only the coarse scale is retained. Part, as shown in Figure 2.
The decomposition and synthesis of different scale coefficients are shown in Figure 3.
Where h(k) and g(k) are a set of conjugate image filters derived from two-scale equations. Aki is the (coarse) scale factor of the i-th layer. The i-th layer is recursively decomposed into a larger-scale portion ak(i+1) and a detail portion dk(i+1) of the i+1 layer.
plastic keychains wholesale,plastic keychain craft,plastic keychain diy,plastic keychain tags,custom plastic keychains
Shenzhen Konchang Electronic Technology Co.,Ltd , https://www.konchangs.com