测绘学报
測繪學報
측회학보
ACTA GEODAETICA ET CARTOGRAPHICA SINICA
2015年
2期
142-149
,共8页
GOCE 卫星%地球重力场模型%能量守恒法%短弧长积分法%平均加速度法%正则化技术
GOCE 衛星%地毬重力場模型%能量守恆法%短弧長積分法%平均加速度法%正則化技術
GOCE 위성%지구중력장모형%능량수항법%단호장적분법%평균가속도법%정칙화기술
GOCE satellite%gravity field model%energy conservation approach%short-arc integral approach%average acceleration approach%regularization technique
欧空局早期公布的时域法和空域法解算的 GOCE 模型均采用能量守恒法处理轨道数据，但恢复的长波重力场信号精度较低，而且 GOCE 卫星在两极存在数据空白，利用其观测数据恢复重力场模型是一个不适定问题，导致解算的模型带谐项精度较低，需进行正则化处理。本文分析了基于轨道数据恢复重力场模型的方法用于处理 GOCE 数据的精度，对最优正则化方法和参数的选择进行了研究。利用 GOCE 卫星2009‐11‐01—2010‐01‐31共92 d 的精密轨道数据，采用不依赖先验信息的能量守恒法、短弧积分法和平均加速度法恢复 GOCE 重力场模型，利用 Tikhonov 正则化技术处理病态问题。结果表明，平均加速度法恢复模型的精度最高，能量守恒法的精度最低，短弧积分法的精度稍差于平均加速度法。未来联合处理轨道和梯度数据时，建议采用平均加速度法或短弧积分法处理轨道数据，并且轨道数据可有效恢复120阶次左右的模型。 Kaula 正则化和 SOT 处理 GOCE 病态问题的效果最好，并且两者对应的最优正则化参数基本一致，但利用正则化技术不能完全抑制极空白问题的影响，需要联合GRACE 等其他数据才能获得理想的结果。
歐空跼早期公佈的時域法和空域法解算的 GOCE 模型均採用能量守恆法處理軌道數據，但恢複的長波重力場信號精度較低，而且 GOCE 衛星在兩極存在數據空白，利用其觀測數據恢複重力場模型是一箇不適定問題，導緻解算的模型帶諧項精度較低，需進行正則化處理。本文分析瞭基于軌道數據恢複重力場模型的方法用于處理 GOCE 數據的精度，對最優正則化方法和參數的選擇進行瞭研究。利用 GOCE 衛星2009‐11‐01—2010‐01‐31共92 d 的精密軌道數據，採用不依賴先驗信息的能量守恆法、短弧積分法和平均加速度法恢複 GOCE 重力場模型，利用 Tikhonov 正則化技術處理病態問題。結果錶明，平均加速度法恢複模型的精度最高，能量守恆法的精度最低，短弧積分法的精度稍差于平均加速度法。未來聯閤處理軌道和梯度數據時，建議採用平均加速度法或短弧積分法處理軌道數據，併且軌道數據可有效恢複120階次左右的模型。 Kaula 正則化和 SOT 處理 GOCE 病態問題的效果最好，併且兩者對應的最優正則化參數基本一緻，但利用正則化技術不能完全抑製極空白問題的影響，需要聯閤GRACE 等其他數據纔能穫得理想的結果。
구공국조기공포적시역법화공역법해산적 GOCE 모형균채용능량수항법처리궤도수거，단회복적장파중력장신호정도교저，이차 GOCE 위성재량겁존재수거공백，이용기관측수거회복중력장모형시일개불괄정문제，도치해산적모형대해항정도교저，수진행정칙화처리。본문분석료기우궤도수거회복중력장모형적방법용우처리 GOCE 수거적정도，대최우정칙화방법화삼수적선택진행료연구。이용 GOCE 위성2009‐11‐01—2010‐01‐31공92 d 적정밀궤도수거，채용불의뢰선험신식적능량수항법、단호적분법화평균가속도법회복 GOCE 중력장모형，이용 Tikhonov 정칙화기술처리병태문제。결과표명，평균가속도법회복모형적정도최고，능량수항법적정도최저，단호적분법적정도초차우평균가속도법。미래연합처리궤도화제도수거시，건의채용평균가속도법혹단호적분법처리궤도수거，병차궤도수거가유효회복120계차좌우적모형。 Kaula 정칙화화 SOT 처리 GOCE 병태문제적효과최호，병차량자대응적최우정칙화삼수기본일치，단이용정칙화기술불능완전억제겁공백문제적영향，수요연합GRACE 등기타수거재능획득이상적결과。
The energy conservation approach has been adopted to exploit GOCE orbit information in earlier GOCE time‐wise and space‐wise gravity field models which are two kinds of official ESA products ,but the accuracy of long‐wavelength gravity signal is low .Gravity field recovery with GOCE satellite data is an ill‐posed problem and the precision of zonal coefficients is low due to the polar gaps ,which needs be processed by regularization technique .This paper analyzes the accuracy of existing approaches for gravity field recovery in processing GOCE data and the selection of optimal regularization techniques and parame‐ters .Several gravity field models were recovered based on GOCE precise orbits of 92‐days from2009‐11‐01 to 2010‐01‐31 with the energy conservation approach ,short‐arc integral approach and average acceleration approach .These approaches do not require any initial values of unknown parameters and reference gravity models .Besides ,the Tikhonov regularization technique was applied to tackle the ill‐posed problem .The results showthat the highest accuracy of the model is recovered by the average acceleration approach ,the lowest accuracy is the energy conservation approach ,and the accuracy of short‐arc integral approach is slightly worse than average acceleration approach .Therefore ,such methods as the average acceleration approach or short‐arc integral approach should be recommended to be applied when processing the GOCE orbit data .Gravity field models can effectively recovered by GOCE orbit data with the order and degree 120 when orbit and gradiometer data are combined to processes in the future .Kaula regularization and second‐order Tikhonov (SOT) are superior to other regularization techniques in dealing with ill‐posed problem of GOCE , and the corresponding optimal regularization parameters of both techniques are consistent . However ,the effects of polar gaps could not be completely inhibited by regularization technique ;it should be combined with other data ,such as GRACE satellite data ,to get the desired results .
