Then they are saved in the database for later use . this research work completely departs from aggps 170 field computer . so it not only provide technical support for establishing low cost and homemade agricultural gps system , but also settles foundation for founding new methods to handle gps data and developing equipments of precision agriculture on the basis of aggps 132 ourselves 这一研究工作完全脱离了对田间专用计算机aggps170的依赖性，既为建立低成本的国产化农用gps应用系统提供了技术支持，也为研究和创建新的gps接收数据处理方法以及使用者自行研制基于aggps132的精细农业装备奠定基础。
E . , embedded computer system is one of the hotest issues in current it - related profession . actually embedded systems are some dedicated computer systems that point to certain concrete applications , routers , ethernet swichers , mobile telephones , pda " s , palm computers , and even mars probers are all its typical application 嵌入式系统即嵌入式计算机系统是当今it行业最热门的话题之一，其实质是针对各种具体应用的专用计算机系统，路由器、以太网交换机、手机、 pda 、掌上电脑、机顶盒、火星探测器等都是它的典型应用。
Embedded system is a customized computer system with particular functions . it is widely applied in various fields due to its small size , low power consumption , low cost and high processing speed . there is far more applied amount of embedded system than of general - purpose computer 嵌入式系统是具有特定功能的专用计算机系统,因其具有体积小,功耗低,成本低和处理速度快等优点而被广泛应用于各个领域,在应用数量上远远超过了各种通用计算机,有着无比广泛的市场前景。
Embedded system is an application specific computer system that focuses on the application and it is based on the computer technologyjts hardware and software is cuttable . the development of embedded systems is very fast during the last ten years , furthermore , as an important part of embedded system , embedded operating system is uesed in the embedded systems more and more , especially in handheld devices and electronic devices . but the design techniques of embedded system and embedd software is still germinant , and there are no standards and universal methods about it 嵌入式系统是以应用为中心，以计算机技术为基础，软硬件可剪裁的专用计算机系统。近十几年来，嵌入式系统的发展异常迅速，嵌入式操作系统作为嵌入式系统的核心，其应用也越来越广泛，尤其在手持设备、信息家电领域更加突出。但嵌入式系统以及嵌入式软件设计技术仍旧处于起步阶段，仍旧未能形成一套完整、有效、通用的开发方法和规范。
It has been widely applied in the situation of strict requirement to function , reliability , cost and power etc . in the thesis , the key technologies of embedded system was researched with the background of the project - " epg network tv system " 嵌入式系统是以应用为中心，以计算机技术为基础，并且软硬件可裁剪，适用于应用系统对功能、可靠性、成本、体积、功耗有严格要求的专用计算机系统。本文结合一个嵌入式应用系统( epg网络电视系统)的研发，对嵌入式系统应用关键技术进行了研究。
It is defined as the special computer system which is oriented to application , base on computer technology , is apt to select software or hardware and is fit in function and reliability , so the embedded system is usually made up of micro processor , related hardware , embedded operation system , application software , and so on 嵌入式系统被定义为：以应用为中心、以计算机技术为基础、软件硬件可裁剪、适应应用系统对功能、可靠性、成本、体积、功耗严格要求的专用计算机系统，因此嵌入式系统主要由嵌入式处理器、相关支撑硬件、嵌入式操作系统及应用软件系统等组成。
Every field has its own special computer network , however they still use the switching network of programming control which is provided by the post telephone and telegraph system . the cost of the telephone is a large part in the spending of every department . instructing the switching network to realize the telephone communication needs much of equipment charges , lines charges , protection charges , project charges and time 虽然各行业都有自己的专用计算机网络，但是各行业仍利用邮电系统提供的程控交换电话网络通信，需支付大量的电话费，占用了各部门的很大一部分开销；建立程控交换电话网络实现电话通信需要大量的设备费、线路费、维护费和工程费等费用，并且需要一定的施工工期。
Embedded system is a computer system , which is focus on application , based on computer technology , and its software and hardware could be pruned , besides embedded system has particular requirement for its reliability , cost , volume and power consume . embedded system is relative to computer system structure , encode theory and work theory , and come down to all kinds of computer interface and memory technology , such as serial and network interface , flash and sdram memory technology . the processor and interface and memory device will be difference when referring to different applications , but , as far as the researching and developing method of embedded system , they are generally same 嵌入式系统是以应用为中心、以计算机技术为基础、软硬件可剪裁并对功能、可靠性、成本、体积和功耗都有严格要求的专用计算机系统,涉及计算机系统的体系结构、编译原理和工作原理,涉及到计算机的各种接口和存储应用,如常用的串口、网络控制等接口和flash 、 sdram等存储技术,此外,因嵌入式系统的应用不同,处理器和接口及存储设备都会有所不同,但就嵌入式系统的研究与开发方法来说有许多相同之处,因而深入研究和设计某种嵌入式系统具有深远的意义。
It is proved that these methods can improve the using accuracy of aggps 132 . compared with the results of aggps 170 field computer , the comp arative position error of point is reduced by 40 % , the accuracy of perimeter is inproved by above 8 . 75 % and that of area is above 25 % . this not only makes the more accurate work possible , but settles theoretical and practical basis for developing our own system to apply to precision agriculture 为验证本文的方法，进行了实地测量，并与采用田间专用计算机aggps170计算机的测量结果作了比较，结果表明：本论文中的计算方法可以提高aggps132的使用精度，并且与aggps170计算机的测量结果相比，点的位置相对误差降低了40以上，长度精度提高了8 . 75以上，面积精度提高了25以上，为实现更高精度的作业提供了可能性，也为开发自己的系统应用于精细农业提供了理论和实践基础，具有很大的应用价值。
