New method for eliminating direction ambiguity of earth surface deformation of satellite interference radar

Abstract

The invention discloses a novel method for eliminating direction ambiguity of earth surface deformation of a satellite interference radar, which comprises the following steps of: solving a variance by using a distance relationship between a phase difference between a plurality of satellite interference radar image pairs and orbits, combining a weighted least square method and using different coherence phase probability density distribution functions; and taking an inverse matrix of the variance matrix as a weighting matrix, and determining the surface water horizontal and vertical motion deformation. According to the method, the multi-beam or lifting-rail multi-mode spaceborne radar interferogram is fused, so that the interference of system errors on the surface deformation observed by the satellite interference radar is eliminated, and the precision of obtaining the three-dimensional surface deformation observed by the satellite interference radar is improved; the method can be applied to real-time dynamic and macroscopic large-scale monitoring of real earth surface three-dimensional deformation such as land subsidence and landslide to provide reliable technical support.

Description

technical field [0001] The invention belongs to the technical field of radar monitoring, and in particular relates to a new method for eliminating ambiguity of satellite interference radar surface deformation direction. Background technique [0002] With the acceleration of urban construction, surface deformation poses a potential risk to the hazards of human living environment. Surface deformation is mainly divided into instantaneous sudden deformation and continuous slow deformation. Land subsidence caused by urban engineering construction and excessive groundwater extraction, etc. Land subsidence has the characteristics of slow development, long duration and difficult prevention and control, which will cause major harm to high-speed railways, buildings and infrastructure, and lifeline projects. Therefore, long-term continuous monitoring of slow deformation such as land subsidence is very important. [0003] At present, the commonly used surface deformation monitoring me...

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Problems solved by technology

[0003] At present, the commonly used surface deformation monitoring method is mainly to use precision level, range finder, GPS, bedrock mark and layer mark to measure the deformation information of the surface based on single point or network method. The monitoring accuracy is high, but it consumes a lot of energy. It is difficult to carry out large-scale deformation monitoring due to human and material resources. Satellite interferometric monitoring technology has the advantages of all-day, all-weather, wide coverage, repeatable observation, and high precision, thus providing an effective means for high-precision surface deformation monitoring

However, the radar measures the slant distance, so it is impossible to tell whether the displacement is from the horizontal direction or the vertical direction, that is, there is direction ambiguity

Satellite interferometric radar measurement only obtains the surface deformation component along the radar line of sight (Line of Sight, LoS), and cannot obtain the three-dimensional deformation of the real surface (vertical, east-west and north-south deformation), that is, the satellite interferometric radar surface deformation direction is blurred, these The disadvantages limit the field of real surface three-dimensional deformation monitoring of satellite interferometric radars such as land subsidence, landslides, volcanic activities, and earthquakes.

[0004] Satellite interferometric radar deformation observation has the disadvantage of inherent direction ambiguity in slant distance measurement, and it is easy to receive interference from surface deformation due to systematic errors, resulting in the problem of time-space loss of coherence

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