摘要
对流层大气水汽引起的信号延迟是影响重轨In SAR高程测量精度的主要因素之一。为了研究大气水汽对重轨In SAR测高精度的影响及基线估计的校正作用,仿真不同分布模式的水汽模型,对SAR主、辅数据进行干涉处理,反演受水汽影响高程并统计分析控制点高程误差。实验结果表明:在7km×7km的SAR数据成像范围内,当水汽含量分布均匀时,控制点测量精度与无水汽影响高程精度相当,当水汽含量分布在0.142~0.283cm和0~0.502cm时,控制点高程中误差分别为9.84m,21.01m,即在In SAR测高中,基线估计可以校正均匀水汽等系统噪声,但是当水汽分布不均匀时,基线估计不能很好抵消水汽影响,且水汽变化越大,测高误差越大,需要根据外部水汽数据消除水汽对In SAR测量的影响。
The atmospheric phase delay caused by tropospheric water vapor （WV） is an important factor to the precision of InSAR（Interferometry Synthetic Aperture Radar） repeart-pass height measurement.For the purpose of researching the WV effect on the InSAR and the correction effect of baseline estimation, this paper builds different water models and implements InSAR experiment on SAR images to retrieve height and analyze the elevation errors of GCPS.Results show that as the test area is 7km×7km,when water vapor is equal-distributed,the precision of GCPs ’ height is invariable between WV affected and unaffected heights,but as the water vapor content is distributed in the range of 0. 142cm to 0.283cm and 0 to 0.502cm,the standard errors of the control points are 9. 84m and 21.02m.We can conclude baseline estimation in InSAR process can offset the system noise of the most equal-distributed WV,but has no ability to offset various WV effect.Meanwhile,the error of retrieved height increases with the greater change of WV content and needs to be corrected with measured WV data.
出处
《海洋测绘》
CSCD
2017年第2期56-59,73,共5页
Hydrographic Surveying and Charting
基金
国家自然科学基金(41474010
61401509)
