新大地坐標(biāo)數(shù)據(jù)管理系統(tǒng)的開發(fā)畢業(yè)論文外文翻譯-免費閱讀
【正文】 地方坐標(biāo)系統(tǒng)是 技術(shù)上合理但管理值得探討的問題。它們彼此互相獨立 ,沒有關(guān)聯(lián)。經(jīng)過數(shù)據(jù)處理 ,現(xiàn)在的國家天文大地網(wǎng)將得到升級。當(dāng)代國家天文大地網(wǎng)的精度為 177。不同系統(tǒng)之間的轉(zhuǎn)換因子也是必不可少的。 現(xiàn)代地理信息產(chǎn)業(yè)的要求 作 為國經(jīng)濟發(fā)展的一個關(guān)鍵點 ,現(xiàn)在地理信息產(chǎn)業(yè)的影響越來越大。政府機構(gòu)負(fù)責(zé)將坐標(biāo)系轉(zhuǎn)換為控制點。1m的全球衛(wèi)星定位系統(tǒng)在 2020年將能夠投入使用。第一階段時系統(tǒng)評價階段 (2020年完成 )。3 m。 國家 A類和 B類大地測量控制網(wǎng)的建成說明我們已經(jīng)開發(fā)出了分米精度級別的絕對 3D大地測量控制網(wǎng)。伴隨著這些進(jìn)展 ,空間 大地網(wǎng)的發(fā)展進(jìn)入了一個嶄新的階段。 (3)參考橢球的軸向并沒有明確定義。 1 中國大地坐標(biāo)系統(tǒng)的概況 在建國初期 ,前蘇聯(lián)的克拉索夫斯基橢球被用來發(fā)展參考坐標(biāo)系。近些年 ,我們就大地基準(zhǔn)的應(yīng)用 ,以及在當(dāng)代和未來的新測量技術(shù)的發(fā)展下開發(fā)大地基準(zhǔn)進(jìn)行了討論。1 m global satellite positioning system will be available in 2020． The popularly used coordinate systems now in our country are 1954 Beijing system and 1980Xi’an system and 10cal systems are also based on these two systems． National coordinate system is actually national astronomic geodetic work． The national geodetic control point accuracy is far from the accuracy of 177。68 m． （ 3） The ellipsoid reference axis direction is not precisely defined． （ 4） Error accumulations are large and accuracy is low． To overe these problems and provide better services for economic development， national defence， and geodesy as well as space research， the Nation． al Surveying Bureau did adjust in one cast to national astronomic geodetic work in the end of 1970s and the beginning of 1980s． The 1980 Xi’an coordinate system was developed． IUGG75 ellipsoid was used in this system． The difference between ellipsoid and geoid is within 420 m and the side accuracy is 1/500 000 after adjustment． A new geodetic coordinate system is planning to meet the scientific needs in our country as the developments of new technologies such as very long base interfere(VLBI)and global positioning Systems(GPS)． The classes A and B GPS work were pleted and put in use respective in 1996 and 1997． The space geodetic work developments entered a new phase with these progresses． It is not only with higher accuracy than former systems but also with three dimension coordinates which developed on internationaly defined ITRF frame． This high accuracy 3D space geodetic coordinate system will guarantee the infrastructure surveying for the first 10 years of twentyfirst eentury． After adjustment， the plate coordinate overlap accuracy of class A GPS work is better than 210。100 m total standard users． A new Global Navigation Satellite System(GNSS)was in March 26， 2020 by European Union(EU)to meet their own benefits． Galileo is a program independent of US GPS developed by EU． According to its plan， Galileo program will include 30 satellites with four phases． The first phase is system evaluation period(pleted in 2020)； the second phase is development and test period(from 2020 to 2020)； the third phase is implementation period(2020 to 2020)； and the fourth phase is mercial operation perod(from 2020)． The characteristics of Galileo are its civil purpose and high accuracy． Free of chargeusers can reach177。 and177。 1954北京坐標(biāo)系和 1980西安坐標(biāo)系是我們使用的兩個國家坐標(biāo)系。 這些問題為 : (1)參考橢球的半長軸尺寸要比現(xiàn)在精確測量的長 100m。校正后，橢球和大地水準(zhǔn)面的誤差在 420m 范圍內(nèi)，面精度為1/500000。絕對精度優(yōu)于 。國家和地方政府嚴(yán)格控制大地坐標(biāo)因子 ,而且數(shù)據(jù)處理也必須是有相關(guān)的政府機構(gòu)負(fù)責(zé)。 歐盟為了滿足他們的利益 ,在 2020年 3月 26日將一個新型的全球衛(wèi)星導(dǎo)航系統(tǒng)初始化。免費用戶精度能達(dá)到177。 全球衛(wèi)星的普及和應(yīng)用需 要開放的坐標(biāo)管理系統(tǒng)。 GPS與 GIS集成接收器收集的數(shù)據(jù)不僅包括坐標(biāo) ,還有圖片 ,屬性 ,拓?fù)浣Y(jié)構(gòu)等等。坐標(biāo)系統(tǒng)的點是所有 GIS數(shù)據(jù)采集和處理的基礎(chǔ)。 第 12次 ISM國際會議的會錄 3 開放式坐標(biāo)管理系統(tǒng)的發(fā)展 升級國家天文大地網(wǎng)坐標(biāo) 系統(tǒng) 由于技術(shù)的限制 ,評估天文大地網(wǎng)的主要傳統(tǒng)技術(shù)因子為相對精度。 A類和 B類網(wǎng)點的絕對精度分別為 ﹢ 41m。然后 ,出于國防安
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