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Satellite radar altimetry for inland hydrologic studies.

机译：用于内陆水文研究的卫星雷达测高仪。

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摘要

Satellite radar altimetry, which is originally designed to measure global ocean surface height, has been applied to inland surface water hydrologic studies. We have developed a water-detection algorithm based on statistical analysis of decadal TOPEX/POSEIDON height measurement time series, used the backscatter coefficient to classify the inland surface properties, and the 10-Hz (corresponding to an along track spatial resolution of 700m) radar waveform-retracked TOPEX data, to be able to observe small (300Km 2) inland bodies of water for hydrologic studies. We applied the algorithm to the selected study regions in Manitoba and northwestern (SW) Ontario, Canada, Amazon River Basin, and southwestern Taiwan. Finally we studied the application of TOPEX altimetry to the 1997 Red River flood monitoring. For the study regions in western Manitoba, the correlation coefficient between stage and TOPEX altimetry data in the large Lakes reaches 0.98 using the 10-Hz retracked data, thus verifying the validity and accuracy of the satellite measurement. The importance of the waveform retracking for the inland water applications is validated by the improvement of the correlation coefficients from 0.34 to 0.87 before and after retracking. We detected the bodies of water, which are otherwise missed by using the original 1-Hz data from the Geophysical Data Records, and illustrated that a higher spatial resolution could be achieved using the individual 10-Hz retracked data. In the Amazon River Basin, the capability of the water-detection algorithm is compared with the use of a high water level mask generated by SAR and other data with a spatial resolution of 100m. It is shown that the algorithm could detect the bodies of water, which are missed by the mask primarily because that the frequency of water fluctuation is more than twice a year at some locations. The bodies of water detected only by the algorithm are confirmed using the detailed local hydrological maps in 3 tested regions. The retrieved water height over the small (300Km 2) body of water was compared with the nearby stage measurement and showed good seasonal agreement. In the southwest Taiwan, the monthly variation of 10-Hz AGC from 1992 to 2002 were examined, it is found that the high AGC values could be used to indicate inundated area. We detected the annual and semi-annual variations from the 10-Hz AGC and 10-Hz retracked water height time series, which are attributable to two rainy seasons per year in the study region. For the study of the 1997 Red River flood, we compared the geographic distribution of sigma0 before, during and after the 1997 flood and found the high sigma0 values (>35dB) indicate the inundated regions. In addition, the comparison of the geographically distributed sigma 0 during Winter, Spring, Summer and Autumn of 1997 showed that the low sigma 0 values (10dB) indicate snow coverage. The retrieved water height measurements in the flooded regions are compared with the nearby USGS stage measurements and showed good agreements. The comparison of 10-Hz individual retracked measurements with the 1-Hz non-retracked height measurements confirmed the importance of the retracked data (with higher spatial variations) in the flood monitoring. Using sigma0 and the retrieved water height measurements, we detected the 1997 flooded regions include the Red River Basin of the North in North Dakota and in western Minnesota, the upper Mississippi River Basin in Minnesota, the Missouri River Basin in southern North Dakota and in South Dakota. The observed flood extents from TOPEX agree well with and complement the USGS stage gauge records.
机译：卫星雷达测高仪最初用于测量全球海洋表面高度，现已应用于内陆地表水文水文学研究。我们基于十年期TOPEX / POSEIDON高度测量时间序列的统计分析开发了一种水探测算法，使用后向散射系数对内陆表面属性进行分类，并使用10Hz（对应于700m的沿航迹空间分辨率）雷达波形回溯的TOPEX数据，以便能够观察较小的（<300Km 2）内陆水域进行水文研究。我们将该算法应用于曼尼托巴省和西北（SW）安大略省，加拿大，亚马逊河流域和台湾西南部的选定研究区域。最后，我们研究了TOPEX测高仪在1997年红河洪水监测中的应用。对于马尼托巴省西部的研究区域，使用10 Hz追踪数据，大湖中的阶段数据和TOPEX测高数据之间的相关系数达到0.98，从而验证了卫星测量的有效性和准确性。对于内陆水域应用，波形重新跟踪的重要性通过将跟踪前后的相关系数从0.34提高到0.87来验证。我们使用地球物理数据记录中的原始1-Hz数据检测了水体，否则会丢失水体，并说明了使用单独的10Hz重跟踪数据可以实现更高的空间分辨率。在亚马逊河流域，将水探测算法的功能与由SAR和其他数据（空间分辨率为100m）生成的高水位掩膜的使用进行了比较。结果表明，该算法可以检测出水面被掩膜遗漏的水体，这主要是因为在某些位置水的波动频率每年两次以上。使用3个测试区域的详细局部水文地图，可以确定仅通过算法检测到的水体。在较小的（<300Km 2）水体上检索到的水高与附近的水位测量值进行了比较，显示出良好的季节性一致性。在台湾西南部，研究了1992年至2002年10 Hz AGC的月变化，发现较高的AGC值可用于指示淹没区域。我们从10赫兹AGC和10赫兹重新跟踪的水高时间序列中检测到了年度和半年度变化，这可归因于研究区域每年的两个雨季。在研究1997年红河洪水时，我们比较了sigma0在1997年洪水之前，之中和之后的地理分布，发现高sigma0值（> 35dB）表示淹没区域。另外，对1997年冬季，春季，夏季和秋季的地理分布sigma 0的比较表明，低sigma 0值（<10dB）表示有雪覆盖。将淹没区域中检索到的水高测量值与附近的USGS阶段测量值进行比较，并显示出良好的一致性。 10 Hz单独重新跟踪的测量值与1 Hz非重新跟踪的高度测量值的比较证实了在洪水监测中重新跟踪的数据（具有更高的空间变化）的重要性。使用sigma0和取回的水高测量值，我们检测到1997年的洪水地区包括北达科他州和明尼苏达州北部的红河盆地，明尼苏达州的密西西比河上游盆地，北达科他州南部和南部的密苏里河流域达科他州。从TOPEX观察到的洪水范围与USGS台面规记录相吻合并相互补充。

著录项

  • 作者

    Zhang, Manman.;

  • 作者单位

    The Ohio State University.;

  • 授予单位 The Ohio State University.;
  • 学科 Geomorphology.;Remote Sensing.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 142 p.
  • 总页数 142
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 遥感技术;
  • 关键词

  • 入库时间 2022-08-17 11:38:29

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