Road Elevation Extraction And Slope Estimation Based On Insar And Multi-source Data

As an important infrastructure,roads play an important role in the fields of national economy and military.In the military field,you can use road fluctuations to assist in path planning,so you need to obtain road elevation information in a certain area in advance,and then estimate the road fluctuations.Synthetic Aperture Radar(SAR)is a new type of microwave remote sensing technology with all-time and all-weather imaging capabilities.Interferometry Synthetic Aperture Radar(InSAR)is a technology that uses the phase information of different temporal SAR images in the same area to retrieve the surface elevation,which could get high-precision,high-resolution ground elevation information.It has a wide range of uses in acquiring surface information.In order to accurately extract road elevation information in a certain area and extract corresponding slope information and slope change points,it is necessary to provide a high-resolution high-precision digital elevation model(DEM)for the area.The traditional DEMs with 90 m and 30 m resolutions can no longer meet our needs.Therefore,the focus of this article is how to quickly obtain a high-resolution and high-precision DEM in a certain area and perform fusion processing with the extracted road binary image.Then obtain accurate road elevation information,and finally use the slope algorithm proposed in this paper to calculate the road’s slope information and change point.This article mainly studies the specific algorithms in the InSAR process and makes improvements.The improved algorithms are programmed to form a complete InSAR information processing system.The main innovations and improvements of this article are as follows:1.For interferogram filtering,a Goldstein frequency domain filtering algorithm based on the phase filtering weight map is improved.This algorithm improves the filter factor in Baran filtering,and can adaptively perform frequency domain filtering on the interferogram after removing flat phase.Comparing the results of the algorithm with other filtering methods,the results show that the algorithm can maintain the integrity of the interference fringe’s edges while filtering out a lot of phase noise.2.In order to obtain the elevation information from phase in the InSAR process,a simplified first-order model is proposed to extract the elevation information.And the obtained elevation information was compared with the reference elevation.The results show that the model has higher elevation calculation accuracy.3.Aiming at the problem of elevation information holes and the inability to extract elevation information due to layover and shadow phenomena in traditional InSAR technology,a fusion strategy based on fusion weight map and coherence coefficient map is improved,which can better solve the problem of lack of elevation information in complex mountainous areas.4.After obtaining the road raster map with elevation information,this paper improves a slope algorithm.After verification,the algorithm can calculate the precise slope value of the road and a large amount of slope change points information.