Carrier phase difference estimation method based on DDMR-assistance for GNSS-R altimetry
-
摘要: 提出了一种基于时延-多普勒映射接收机(DDMR,Delay-Doppler Map Receiver)辅助的载波相位差提取方法,给出了系统结构及信号处理方法.该方法将DDMR中所观测到的码相位差作为直射信号与反射信号的码相位延时量,将完成跟踪的直射信号扩频码进行对应的延时用于完成对反射信号的开环码跟踪.该方法省去了码相位延时搜索的过程,且可以准确地对反射信号扩频码进行同步.为了验证系统的可行性及实际性能,进行了针对水面高度测量的岸基试验并给出了试验结果.岸基试验证明采用该方法的GNSS-R(Global Navigation Satellite System Reflection)接收机可以稳定地对反射信号进行跟踪并提取直射与反射信号的载波相位差,测高精度约为2.5 cm,经过0.5 s的数据平均后精度可达0.6 cm.Abstract: A carrier phase difference estimation method based on the delay-Doppler map receiver (DDMR)-assistance for (GNSS-R) coastal altimetry was proposed. The system structure and the signal processing method were given. The proposed method, which can avoid the complicated search for the GNSS spreading codes, uses the code phase difference observed from DDMR as the estimated time-delay between the spreading codes of the direct signal and the reflected signal, and then delays the tracked codes of the direct signal to achieve the open-loop tracking of the reflected signal. Field experiments with real coastal receivers demonstrate the effectiveness of this method, which can steadily track the weak reflected signal and accurately extract the difference of the carrier phase. The experiment results show that the altimetry accuracy is about 2.5 cm without data average or 0.6 cm with 0.5 s average.
-
Key words:
- global navigation satellite system (GNSS) /
- reflected signal /
- receiver
-
[1] Martin-Neira M.A passive reflectometry and interferometry system (PARIS):application to ocean altimetry[J].ESA Journal, 1993, 17:331-355 [2] Valencia E, Camps A, Park H, et al.Impact of the observation geometry on the GNSS-R direct descriptors used for sea state monitoring[C]//International Geoscience and Remote Sensing Symposium (IGARSS).Piscataway, NJ:IEEE, 2012:2825-2828 [3] Soulat F, Caparrini M, Germain O, et al.Sea state monitoring using coastal GNSS-R[J].Geophys Res Lett, 2004, 31(21):L21303 [4] Marchan-Hernandez J F.Sea state determination using GNSS-R techniques:contributions to the PAU instrument[D].Barcelona: Univ Politecnica de Catalunya, 2009 [5] Zavorotny V U, Voronovich A G.Scattering of GPS signals from the ocean with wind remote sensing application[J].IEEE Trans Geosci Remote Sens, 2000, 38(2):951-964 [6] 路勇, 杨东凯, 熊华刚, 等.基于GNSS-R的海面风场检测系统研究[J].武汉大学学报, 2009, 34(4):470-473 Lu Yong, Yang Dongkai, Xiong Huagang, et al.Study of ocean wind-field monitoring system based on GNSS-R[J].Geomatics and Information Science of Wuhan University, 2009, 34(4): 470- 473(in Chinese) [7] Garrison J L, Komjathy A, Zavorotny V U, et al.Wind speed measurement using forward scattered GPS signals[J].IEEE Trans Geosci Remote Sens, 2002, 40(1):50-602 [8] Fabra F, Cardellach E, Rius A, et al.Phase altimetry with dual polarization GNSS-R over sea ice[J].IEEE Transactions on Geoscience and Remote Sensing, 2012, 50(6):2112-2121 [9] Zavorotny V U, Voronovich A G.Bistatic GPS signal reflections at various polarizations from rough land surface with moisture content[C]//International Geoscience and Remote Sensing Symposium (IGARSS).Piscataway, NJ:IEEE, 2000:2852-2854 [10] Valencia E, Camps A, Rodriguez-Alvarez N, et al.Using GNSS-R imaging of the ocean surface for oil slick detection[J].IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2013, 6(1):217-223 [11] Germain O, Ruffini G, Soulat F, et al.The eddy experiment:GNSS-R speculometry for directional sea-roughness retrieval from low altitude aircraft[J].Geophysical Research Letters, 2004, 31(21):L21307 [12] Marchan-Hernandez J F, Rodriguez-Alvarez N, Camps A, et al.Correction of the sea state impact in the L-band brightness temperature by means of delay-Doppler maps of global navigation satellite signals reflected over the sea surface[J].IEEE Transactions on Geoscience and Remote Sensing, 2008, 46(10):2914-2923 [13] Rodriguez-Alvarez N, Akos D M, Zavorotny V U, et al.Airborne GNSS-R wind retrievals using delay & Doppler maps[J].IEEE Transactions on Geoscience and Remote Sensing, 2013, 51(1):626-641 [14] Helm A, Beyerle G, Potsdam M N G, et al.Detection of coherent reflections with GPS bipath interferometry[EB/OL].New York:Cornell University Library, 2004[2013-04-01].http://arxiv.org/abs/physics/0407091 [15] Ruffini G, Caparrini M, Ruffini L.PARIS altimetry with L1 frequency data from the bridge 2 campaign experiment[R].CCN3-WP3 Technical Report, ESA/ESTEC Contract No.14285/85/nl/pb, 2002 [16] Wang Yiran, Zhang Bo, Shao Dingrong.Differential coherent algorithm based on fast navigation-bit correction for airborne GNSS-R software receivers[J].Tsinghua Science and Technology, 2013, 18(1):88-99 [17] Hajj G A, Zuffada C.Theoretical description of a bistatic system for ocean altimetry using the GPS signal[J].Radio Science, 2003, 38(5):1089
点击查看大图
计量
- 文章访问数: 1840
- HTML全文浏览量: 191
- PDF下载量: 478
- 被引次数: 0