基于IMU的机载TOPSAR目标定位方法
收稿日期: 2015-05-06
修回日期: 2015-09-22
网络出版日期: 2015-10-19
基金资助
国家自然科学基金(61172122)
Target geo-location method in airborne TOPSAR mode based on IMU
Received date: 2015-05-06
Revised date: 2015-09-22
Online published: 2015-10-19
Supported by
National Natural Science Foundation of China (61172122)
Burst工作模式和方位波束的主动扫描使得TOPSAR工作模式能够有效削弱ScanSAR模式的扇贝效应,同时也导致图像方位向像素位置与回波脉冲的关系变得复杂,给目标定位带来了很多问题。惯性测量单元(IMU)数据记录延时也会导致方位向定位误差存在,精确估计这个误差能够大大提高目标的方位向定位精度。从TOPSAR数据采集的几何关系和成像过程出发,结合机载IMU数据,提出了一种新的机载TOPSAR目标定位方法。该方法能够直接从TOPSAR斜距图像中获取目标的经纬度信息。通过实际飞行试验获取的机载TOPSAR数据验证了该方法的有效性,能够获取25 m的平均定位精度。
范怀涛 , 张志敏 , 李宁 , 魏云龙 . 基于IMU的机载TOPSAR目标定位方法[J]. 航空学报, 2016 , 37(5) : 1587 -1594 . DOI: 10.7527/S1000-6893.2015.0261
In the terrain observation by progressive scans synthetic aperture radar (TOPSAR) mode, the application of burst mode and beam steering in the azimuth can effectively weaken scalloping effect, which is an inherent defect in ScanSAR mode. In addition, several problems arise in TOPSAR mode, such as the complex relationship between image pixels and the corresponding echo pulses, which makes it difficult to geo-locate targets precisely. Meanwhile, time-lapse in the process of recording inertial measurement unit (IMU) data will worsen the location accuracy in azimuth and precise estimation of the error will greatly improve geo-location performance. Proceeding from the geometric relationship of data acquisition and imaging algorithm in TOPSAR mode, a new target geo-location method is proposed with the usage of airborne IMU data. The presented method can provide longitude and latitude information of targets from processed imagery. Tests have been conducted using airborne TOPSAR imagery to verify the proposed method and average geo-location accuracy of twenty-five meters can be obtained.
[1] CURLANDER J C. Location of spaceborne SAR imagery[J]. IEEE Transactions on Geoscience and Remote Sensing, 1982, GE-20(3):359-364.
[2] CURLANDER J C. Utilization of spaceborne SAR data for mapping[J]. IEEE Transactions on Geoscience and Remote Sensing, 1984, GE-22(2):106-112.
[3] ZAN F D, GUARNIERI A M. TOPSAR:Terrain observation by progressive scans[J]. IEEE Transactions on Geoscience and Remote Sensing, 2006, 44(9):2352-2360.
[4] META A, PRATS P, STEINBRECHER U, et al. TerraSAR-X TOPSAR and ScanSAR comparison[C]//20087th European Conference on Synthetic Aperture Radar (EUSAR).Piscataway, NJ:IEEE Press, 2008:1-4.
[5] META A, MITTERMAYER J, PRATS P, et al. TOPS imaging with TerraSAR-X:Mode design and performance analysis[J]. IEEE Transactions on Geosciences Remote Sensing, 2010, 48(2):759-769.
[6] PRATS P, SCHEIBER R, MITTERMAYER J, et al. Processing of sliding spotlight and TOPS SAR data using baseband azimuth scaling[J]. IEEE Transactions on Geosciences Remote Sensing, 2010, 48(2):770-780.
[7] GEBERT N, KRIEGER G, MOREIRA A. Multichannel azimuth processing in ScanSAR and TOPS mode operation[J].IEEE Transactions on Geosciences and Remote Sensing, 2010, 48(7):2994-3008.
[8] 沈汀. 基于INS/GPS数据的机载SAR图像地理编码系统研究[J]. 电子与信息学报, 2001, 23(1):68-74. SHEN T. Studies on geolocation system for airborne SAR imagery based on INS/GPS data[J]. Journal of Electrics and Information Technology, 2001, 23(1):68-74(in Chinese).
[9] 高祥武,黄广民, 杨汝良. 机载SAR目标快速定位方法和定位精度分析[J]. 现代雷达, 2004, 26(9):4-7. GAO X W, HUANG G M, YANG R L. Study on a fast target location method for airborne SAR and location precision analysis[J]. Modern Radar, 2004, 26(9):4-7(in Chinese).
[10] WONNACOTT W M. Geolocation with error analysis using imagery from an experimental spotlight SAR[D]. Indiana:Graduate School of Purdue University,2008:141-230.
[11] 郑世超, 宋红军, 刘亚波, 等. 广域监视动目标检测模式下动目标快速定位误差分析[J]. 雷达学报, 2013, 2(4):445-453. ZHENG S C, SONG H J, LIU Y B, et al. Error analysis of fast-moving target geo-location in wide area surveillance ground moving target indication mode[J]. Journal of Radars, 2013, 2(4):445-453(in Chinese).
[12] 宋伟, 朱岱寅, 李勇. 机载聚束SAR图像定位精度研究[J]. 数据采集与处理, 2014, 29(4):555-561. SONG W, ZHU D Y, LI Y. Airborne spotlight SAR geolocation accuracy[J]. Journal of Data Acquisition and Processing, 2014, 29(4):555-561(in Chinese).
[13] 徐伟, 邓云凯. 星载TOPSAR方位变标成像算法[J]. 电子学报, 2011, 39(4):913-918. XU W, DENG Y K. Processing of spaceborne TOPSAR data using azimuth scaling[J]. Acta Electronica Sinica, 2011, 39(4):913-918(in Chinese).
[14] IAN G C, FRANK H W. 合成孔径雷达成像-算法与实现[M]. 洪文, 胡东辉, 译. 北京:电子工业出版社, 2007:83-84. IAN G C, FRANK H W. Digital processing of synthetic aperture radar data:algorithms and implementation[M]. HONG W, HU D H, translated. Beijing:Electronic Industry Press, 2007:83-84(in Chinese).
[15] 卫宇. 考虑地球曲率情况下两点距离问题的求解[J]. 航空兵器, 2008(3):7-12. WEI Y. Solution of distance between two points considering curvature of the earth[J]. Aero Weaponry, 2008(3):7-12(in Chinese).
/
| 〈 |
|
〉 |
CJA