星载X波段InSAR数据森林高度估测及反演研究

Forest Height Estimation and Inversion of Satellite-Based X-band InSAR Data

    摘要
  • 摘要: 基于TerraSAR/TanDEM-X星载单极化合成孔径雷达干涉测量（interferometric synthetic aperture radar,InSAR）数据,研究森林高度估测算法选择、相干系数计算方法对估测结果在不同尺度下的影响。采用数字表面模型(digital surface model,DSM）与数字高程模型(digital elevation model,DEM）差分法（DSM-DEM差分法）和基于sinc函数的sinc模型法进行森林高度反演,分析X波段穿透性和不同相干性计算方法对估测结果的影响；通过对比两种高度估测算法在不同尺度下的结果,分析算法选择与尺度对估测结果的影响。实验结果表明,DSM-DEM差分法会在一定程度上低估森林高度；相干性计算方法对sinc模型的森林高度估测结果影响显著,由传统方法计算的相干性得出的估测结果严重高估了森林高度,而由仅考虑相位方法计算的相干性得出的估测结果与激光雷达获取的冠层高度模型一致性较好；随着尺度的增大,两种森林高度估测算法的精度均呈稳步提升。因此,参数的修正、参数计算方法的选择等均会明显引起森林高度估测结果的不确定性；两种估测算法均能得到具有一定可靠程度的森林高度,但是基于相干性的sinc模型法不需要实测数据标定,也不依赖于高精度DEM,具有更加广泛的实用价值；由仅考虑相位方法计算的相干性得出的森林高度估测结果具有更高的精度,更适用于sinc模型的森林高度反演。

     

    Abstract:
    Objectives Based on TerraSAR/TanDEM-X spaceborne single-polarization interferometric synthetic aperture radar (InSAR) data, this paper investigates the impacts of algorithm selection and coherence coefficient calculation methods on forest height estimation across different scales using InSAR technology.
    Methods The DSM（digital surface model）-DEM（digital elevation model） differential algorithm and the sinc model are used for forest height inversion. The effects of X-band penetration on the forest height estimation results are analyzed based on the DSM-DEM differential algorithm, and the effects of the traditional coherence calculation method and the phase-only coherence calculation method on the estimation results are analyzed based on the sinc model. The effects of different scales on the forest height estimation results of the above two estimation algorithms are also clarified.
    Results The experimental results show that the DSM-DEM differential algorithm underestimates the forest height, and the coherence calculation method has a significant effect on the forest height estimation results of the sinc model. The estimation results derived from the coherence calculated by the traditional method overestimate the forest height, while the estimation results derived from the coherence calculated by the coherence-only method are in good agreement with the light detection and ranging acquired canopy height model. The two forest height estimation algorithms show a steady improvement in the estimation accuracy with the increa-sing scales.
    Conclusions The uncertainty of forest height estimation results can be significantly affected by the adjustment of methods, parameters, and the choice of parameter calculation methods. Both methods achieve reliable forest height estimates, but the coherence-based sinc model has broader practical value because it does not require real data calibration or high-precision DEM. Furthermore, the phase-only coherence calculation yields higher accuracy and is more suitable for forest height inversion in the sinc model.

     

    • HTML全文
    • 参考文献(31)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回