30results about How to "Improve elevation accuracy" patented technology

The invention provides a high resolution image laser radar vertical control point extracting and auxiliary positioning method. The method has a core that high resolution remote sensing image vertical control points and image control points are extracted through combined treatment of height measurement laser radar data and high resolution image data and improvement of high resolution image positioning precision is realized through constructing a high resolution image positioning model having elevation restriction. According to the invention, with the support of the height measurement laser radar data, stereoscopic positioning precision of the high resolution remote sensing images and high resolution image mapping product precision are improved distinctively.

The invention provides a satellite attitude error correction method and a satellite attitude error correction device based on laser altitude measurement data. The method includes the steps of: 1) calculating a first distance value between a ground three-dimensional coordinate being corresponded to a corresponding image point and a satellite; 2) calculating the difference between a second distance value and the first distance value, wherein the second distance value is the distance, which is accurately measured by a satellite laser altitude measurement instrument, between a ground point and the satellite; 3) according to the difference, determining whether the satellite attitude error needs to be corrected or not; 4) if the satellite attitude error needs to be corrected, calculating corrected satellite attitude parameters according to the second distance value, the ground three-dimensional coordinate being corresponded to a corresponding image point, satellite-borne camera parameters, and present satellite attitude parameters. The satellite attitude error correction method is based on the laser altitude measurement data, wherein high-precision distance measuring information is acquired by means of the laser altitude meter supported on the same platform of the satellite, thereby detecting and effectively correcting the attitude angle measurement error of the satellite. The method and device can improve the height accuracy of a satellite image without ground control, effectively solve a difficult problem of high-precision mapping for overseas regions, and save cost.

The invention discloses a water area elevation processing method for making a DEM (Dynamic Effect Model) based on an INSAR (Interferometric Synthetic Aperture Radar). The water area elevation processing method comprises the following steps: 1, acquiring original measurement data of a region to be measured; 2, carrying out water area elevation processing, namely, performing elevation processing on a static water area and / or flowing water area in the region to be measured, wherein the static water area is processed as follows: 2011, judging level; 2012, processing the level, comprising the steps of I, extracting a bay line; II, assigning an elevation value on the bay line; and III, correcting the water level elevation; and the flowing water area is processed as follows: 2021, judging vertical adjustment; 2022, processing the vertical adjustment, comprising the steps of i, extracting a bay line; ii, assigning a bay line elevation and processing adjustment; iii, constructing an irregular triangular net and an interpolation water level elevation; and iv, correcting a water level elevation. The water area elevation processing method disclosed by the invention is simple in steps, reasonable in design, convenient to realize, good in use effect, and capable of simply and rapidly completing a water area elevation processing process with high quality; the made DEM is high in elevation precision.

The invention discloses a method and a system for elevation precision control and correction of island remote sensing mapping, and relates to the technical field of geodetic surveying engineering. The method comprises the steps of S1, extracting shorelines from island remote sensing images; S2, obtaining a first average sea surface height and a second average sea surface height, and performing datum conversion on the second average sea surface height; S3, calculating geoidal surface; S4, carrying out harmonic analysis to obtain a tidal harmonic constant; S5, calculating elevation of mean high-water springs; S6, calculating and removing systematic errors of the shorelines in the island remote sensing images; and S7, fitting the shorelines in the island remote sensing images with the systematic errors removed and the shorelines on the mean high-water springs. Correction of the shorelines in the island remote sensing images is realized by fitting the fitting the shorelines in the island remote sensing images with the systematic errors removed and the shorelines on the mean high-water springs, thereby increasing the elevation precision obtained by the island remote sensing mapping.

The invention provides an associated high-precision positioning treatment method for single linear array satellite laser. The method comprises the following steps: using a single linear array satellite to swing along a track, using a set intersection angle to obtain a stereoscopic image of a ground target, and obtaining image space coordinates of corresponding image points through registration ofthe stereoscopic image; using initial orientation parameters and image coordinates of linear array images to calculate pass point initial matter square coordinates; carrying out registration on laser-measured height data and linear array images to obtain image space coordinates corresponding to laser points; constructing an error formula and a corresponding weight matrix; establishing a normal equation, answering image positioning model parameters and the correction numbers of pass point ground coordinates, and amending the image positioning model parameters and the pass point ground coordinates; calculating mean square errors, judging the difference between two mean square errors is smaller than a given limit error, carrying out iteration according to a judgment result, and outputting thecalculated image positioning model parameters and pass point ground coordinates. The data acquisition capacity also can be strengthened while the positioning accuracy is improved, and the timelinessof remote sensing information is guaranteed.

The invention relates to the technical field of power engineering survey, in particular to a remote-sensing aerial surveying elevation fitting method. The remote-sensing aerial surveying elevation fitting method comprises the following steps: setting a field surveyed monitoring point, surveying three-dimensional coordinate data of the monitoring point by using a field surveying instrument, and determining a field surveyed elevation surface; surveying a large-scale topographic map, extracting three-dimensional coordinate data of the large-scale topographic map; in combination with a data value of the field surveyed elevation surface, performing elevation fitting on the three-dimensional coordinate data of the large-scale topographic map by using a polynomial fitting model, and working out an elevation correcting value of each point in the large-scale topographic maps; and correcting the elevation data of the large-scale topographic map by a triangular planar fitting method to the field surveyed elevation surface so as to obtain the elevation value of each point in the large-scale topographic map. Through the adoption of the remote-sensing aerial surveying elevation fitting method, the elevation precision of the large-scale topographic map is effectively improved, thus meeting a requirement on the precision of the surveyed elevation of the large-scale topographic map in survey specifications.

The invention provides an airborne interferometric synthetic aperture radar complex scene elevation inversion method and system. The method comprises the steps: acquiring multiple single-view compleximage pairs of the same complex scene to be detected at opposite angles in a flight mode; respectively obtaining coordinate information of each single-view complex image pair under different coordinate systems according to all the single-view complex image pairs, wherein each piece of coordinate information contains one piece of corresponding first height information; respectively mapping each piece of coordinate information of all the single-view complex image pairs to coordinate transformation under the same coordinate system to obtain each piece of transformed coordinate information and second height information corresponding to each piece of transformed coordinate information after the first height information is transformed; performing gridding processing on each piece of coordinate information after coordinate conversion and the second height information to generate each piece of coordinate information containing third height information; and according to a preset fusion strategy, performing pixel fusion processing on the plurality of pieces of coordinate information containing the third height information, thus generating height inversion information of the to-be-detected complex scene.

The invention relates to the technical field of power engineering survey, in particular to a remote-sensing aerial surveying elevation fitting method. The remote-sensing aerial surveying elevation fitting method comprises the following steps: setting a field surveyed monitoring point, surveying three-dimensional coordinate data of the monitoring point by using a field surveying instrument, and determining a field surveyed elevation surface; surveying a large-scale topographic map, extracting three-dimensional coordinate data of the large-scale topographic map; in combination with a data value of the field surveyed elevation surface, performing elevation fitting on the three-dimensional coordinate data of the large-scale topographic map by using a polynomial fitting model, and working out an elevation correcting value of each point in the large-scale topographic maps; and correcting the elevation data of the large-scale topographic map by a triangular planar fitting method to the field surveyed elevation surface so as to obtain the elevation value of each point in the large-scale topographic map. Through the adoption of the remote-sensing aerial surveying elevation fitting method, the elevation precision of the large-scale topographic map is effectively improved, thus meeting a requirement on the precision of the surveyed elevation of the large-scale topographic map in survey specifications.

The invention discloses a combined surveying and mapping processing method of laser altimetry points and three-line array stereoscopic images on the same track. In the method, the laser altimetry points are used as elevation control points, and the relative plane error of the orthographic images obtained by the laser altimetry points and the same track is used. Smaller features, to obtain the accurate image square coordinates of the laser altimetry points distributed in various terrain types (especially hills and mountainous terrain) on the three-line array stereo image; Construct the adjustment area network, and carry out the joint area network adjustment of the laser altimetry point and the stereo image; finally, update the imaging geometric model of the stereo image according to the adjustment results. The invention makes full use of the advantages of laser altimetry points and optical images being acquired on the same track and has extremely high elevation accuracy. Under the condition of no ground control point, the elevation accuracy of the three-line array stereoscopic image is effectively improved, and it provides a global high-precision solution for the use of satellite images. The construction of geographic information resources provides technical support.

The invention provides a satellite attitude error correction method and a satellite attitude error correction device based on laser altitude measurement data. The method includes the steps of: 1) calculating a first distance value between a ground three-dimensional coordinate being corresponded to a corresponding image point and a satellite; 2) calculating the difference between a second distance value and the first distance value, wherein the second distance value is the distance, which is accurately measured by a satellite laser altitude measurement instrument, between a ground point and the satellite; 3) according to the difference, determining whether the satellite attitude error needs to be corrected or not; 4) if the satellite attitude error needs to be corrected, calculating corrected satellite attitude parameters according to the second distance value, the ground three-dimensional coordinate being corresponded to a corresponding image point, satellite-borne camera parameters, and present satellite attitude parameters. The satellite attitude error correction method is based on the laser altitude measurement data, wherein high-precision distance measuring information is acquired by means of the laser altitude meter supported on the same platform of the satellite, thereby detecting and effectively correcting the attitude angle measurement error of the satellite. The method and device can improve the height accuracy of a satellite image without ground control, effectively solve a difficult problem of high-precision mapping for overseas regions, and save cost.

The invention belongs to the field of a medium-resolution remote sensing image discrete point DEM (Digital Elevation Model) construction method, which discloses a medium-resolution remote sensing image discrete point DEM construction method based on medium value filtering. The medium-resolution remote sensing image discrete point DEM construction method comprises the following steps of: 1. calculating tidal height information at a satellite imaging moment; 2. dispersing a vector waterline extracted at the satellite imaging moment; 3. combining equidistant tidal level points dispersed in the above steps, building the reference grid of the median filtering according to a remote sensing image resolution ratio, labeling all dispersed equidistant tidal level points, and marking the ID (Identity) of the grid to which the equidistant tidal level points belong; 4. traversing all grids; and 5. on the basis of a median filtering result, building a final DEM result by linear interpolation. In the method disclosed by the invention, the method of median filtering effectively utilizes the elevation information of all discrete points falling in the grids to improve the elevation precision of the discrete point.

The invention discloses a method for assisting block adjustment by using Gaofen-7 laser height measurement data, which combines Gaofen-7 laser height measurement data footprint images, realizes automatic extraction of elevation control points based on laser height measurement data, establishes a combined block adjustment model of laser height measurement data assisted stereoscopic images, model unification under the conditions of no control, field control and elevation control is realized; and laser height measurement data is used as elevation control to be applied to adjustment calculation, so that the geometric accuracy of the regional image is improved. According to the method provided by the invention, the elevation precision of the block can be greatly improved only by using laser height measurement data as elevation control in areas covering different terrain types.

The invention discloses a method for using a laser altimetry point in an undulating surface area as an image elevation control point. Firstly, full waveform processing is performed on the echo signal of a laser point in the undulating surface area to obtain the maximum and minimum elevation values ​​of the ground surface in the ground footprint of the laser point. Then use the high-precision registration of the laser footprint image and the stereo image to obtain the range of the ground footprint of the laser point on the stereo image. Then, image dense matching is carried out within the range of the ground footprint of the laser point on the stereoscopic image to generate a 3D point cloud on the ground, and the corresponding image point coordinates of the 3D ground points with the largest and smallest elevation values ​​on the stereoscopic image are obtained. Finally, the maximum and minimum elevation values ​​of the ground surface in the ground footprint of the laser point are assigned to them respectively, that is, two elevation control points on the stereoscopic image are obtained through one laser point. The invention breaks through the previous limitation that the laser point in the surface undulation area cannot be used for elevation control because the accurate elevation of the center point of the footprint cannot be obtained, and greatly improves the utilization rate of the laser point in the surface undulation area.

The invention discloses a floating adjustment method combining GPS and SRTM fusion. The method comprises the following steps: 1) establishing an adjustment model of a known first GPS point and nine adjacent grids corresponding to an SRTM grid at the first known GPS point; 2) solving the adjustment model to calculate improved elevation values corresponding to the SRTM grid and four angular points;3) taking the four angular points as known values of the next round of improved SRTM, solving a difference value between a new value obtained after adjustment fusion of each layer and an original gridvalue, and if a mean value (threshold value is less than 0.5 m) of the difference values, determining that the algorithm converges; and 4) continuously searching a second known GPS point in the areaoutside the first GPS point, and then carrying out a second round of improvement, the method being consistent with the first GPS point until the fusion of the whole area is completed, and the method can improve the elevation precision of the SRTM of the fusion area.

The invention discloses a method and a system for elevation precision control and correction of island remote sensing mapping, and relates to the technical field of geodetic surveying engineering. The method comprises the steps of S1, extracting shorelines from island remote sensing images; S2, obtaining a first average sea surface height and a second average sea surface height, and performing datum conversion on the second average sea surface height; S3, calculating geoidal surface; S4, carrying out harmonic analysis to obtain a tidal harmonic constant; S5, calculating elevation of mean high-water springs; S6, calculating and removing systematic errors of the shorelines in the island remote sensing images; and S7, fitting the shorelines in the island remote sensing images with the systematic errors removed and the shorelines on the mean high-water springs. Correction of the shorelines in the island remote sensing images is realized by fitting the fitting the shorelines in the island remote sensing images with the systematic errors removed and the shorelines on the mean high-water springs, thereby increasing the elevation precision obtained by the island remote sensing mapping.

The invention discloses a method for using Gaofen-7 laser altimetry data to assist regional network adjustment. The method combines the footprint image of Gaofen-7 laser altimetry data to realize automatic elevation control point based on laser altimetry data. Extracted and established a joint area network adjustment model of the laser altimetry data-assisted stereo image, realizing the model unification under the conditions of no control, field control and elevation control; the laser altimetry data was applied to the adjustment calculation as an elevation control , to improve the geometric accuracy of regional images. The method described in the present invention can greatly improve the elevation accuracy of the area network by using only laser altimetry data as elevation control in areas covering different terrain types.

The invention provides a multi-process double-linear-array image matching method based on a laser elevation control point library, and belongs to the field of satellite laser ranging. The method comprises a construction technology of a laser elevation control point library and a double-linear-array image matching technology based on the laser elevation control point library. And constructing a laser elevation control point database by using SQLite. A sub-table storage mechanism and a naming criterion are established when the database is constructed; based on double-linear-array image matching of a laser elevation control point library, a rearview image is partitioned mainly according to a construction mechanism of the laser elevation control point library and an imaging mechanism of double-linear-array images, and a laser elevation control point required by each to-be-processed image is determined by quickly traversing the laser elevation control point database through MPI multiple processes. According to the method, satellite-borne laser altimetry data is used as an elevation control constraint condition to participate in block adjustment calculation of the image, so that the uncontrolled stereo mapping precision of the optical satellite image can be effectively improved, and a large-scale stereo satellite mapping project without a ground control point is realized.

The invention relates to a precise positioning and fixing device for embedded steel bars in a cast-in-place bottom plate of a fabricated channel side wall. The precise positioning and fixing device comprises a lower-layer horizontal positioning and fixing frame, a middle-layer horizontal positioning and fixing frame, an upper-layer horizontal positioning and fixing verification sleeve plate and a plurality of vertical rods. The lower-layer horizontal positioning and fixing frame comprises two fixing frame long rods, a positioning toothed plate strip and a plurality of transverse rods; the middle-layer horizontal positioning and fixing frame and the lower-layer horizontal positioning and fixing frame are the same in structure; the vertical rods are arranged between the middle-layer horizontal positioning and fixing frame and the lower-layer horizontal positioning and fixing frame; and the upper-layer horizontal positioning and fixing verification sleeve plate is correspondingly arranged above the middle-layer horizontal positioning and fixing frame, and the top ends of the vertical rods exceed the upper-layer horizontal positioning and fixing verification sleeve plate. The invention further relates to a construction method of the precise positioning and fixing device for the embedded steel bars in the cast-in-place bottom plate of the fabricated channel side wall. The problems that in the construction process of cast-in-place bottom plate pre-embedded vertical steel bars, the positioning deviation is large, binding is loose, and fixing is not firm can be solved.

The invention discloses a circular ring region recommendation point algorithm based on elevation, and the algorithm comprises the following steps: S1, obtaining parameter region center data, starting radius data and ending radius data, and determining the region range of a circular ring according to the input parameter region center, starting radius and ending radius; s2, equally dividing the circular ring into n quadrants by inputting the number of parameter recommendation points, sequentially reading the elevation value of each quadrant, calculating the longitude and latitude height of each point according to the elevation value of each quadrant through the azimuth angle relative to the center of the region and the distance, and then reading all the elevation values in each quadrant; s3, traversing each quadrant, sequentially calculating a high point of each quadrant according to the elevation value of each quadrant read in the step S2, and taking the high point as a recommended point; and S4, judging whether the recommendation point of the current quadrant is smaller than the specified height, and if so, not recommending the quadrant.

The present invention is an adaptive correction method for the intersection error of surveying and mapping satellites, comprising the following steps: using any left and right view stereoscopic images in the same area, it is proposed to use RPC parameters and SRTM data to calculate the basic matrix of affine transformation on the basis of matching points of the same name F, use the SIFT algorithm to extract, match and optimize key points on the left and right stereoscopic images, and calculate the translation correction matrix T of the intersection error. After translation correction, the residual error reaches the sub-pixel level, thereby effectively ensuring the elevation accuracy. The invention does not need ground control points, and under the condition of multiple stereo images with different base-height ratios, it can self-adaptively correct the intersection error, and greatly improve the elevation accuracy of satellite surveying and mapping.

The invention discloses a three-dimensional city modeling method based on BIM and GIS, comprising the following steps: data measurement, data processing, establishment of a BIM model, establishment of a three-dimensional GIS model, model fusion, municipal simulation, element splitting and optimization, model rendering and Display; the present invention can easily obtain the precise height, appearance size and internal space information of the building through BIM, thus integrating BIM and GIS, first modeling the building, and then sharing the building space information with its surrounding geographical environment, and applying it to the three-dimensional city In GIS analysis, the cost of building space information can be reduced without a large amount of manual interactive modeling, and the use of unmanned aerial vehicles and unmanned vehicles to collect data has high efficiency, short production cycle and strong timeliness. At the same time, the present invention collects data Finally, through data classification and comparison, calculation and simulation of point cloud and aerial photo data, the elevation information of ground objects is improved, the elevation accuracy of building models is high, and the roof is more refined.

The invention discloses a method for taking a laser height measurement point in a surface relief area as an image elevation control point, which comprises the following steps of firstly, carrying out full-waveform processing on a laser point echo signal in the surface relief area to obtain a maximum surface elevation value and a minimum surface elevation value in a laser point ground footprint; and then high-precision registration of the laser footprint image and the three-dimensional image being utilized to obtain a laser point ground footprint range on the three-dimensional image; carrying out image dense matching in a laser point ground footprint range on the stereoscopic image, generating a ground three-dimensional point cloud, and obtaining corresponding image point coordinates of ground three-dimensional points with the maximum elevation value and the minimum elevation value on the stereoscopic image; and finally, respectively endowing a maximum elevation value and the minimum elevation value of the ground surface in the ground footprint of the laser point to a maximum elevation value and the minimum elevation value, namely, obtaining two elevation control points on the stereoscopic image through one laser point. According to the method, the limitation that the laser points in the surface relief area cannot be used for elevation control due to the fact that the precise elevation of the footprint center point cannot be obtained in the past is broken through, and the utilization rate of the laser points in the surface relief area is greatly improved.

The invention discloses a water area elevation processing method for making a DEM (Dynamic Effect Model) based on an INSAR (Interferometric Synthetic Aperture Radar). The water area elevation processing method comprises the following steps: 1, acquiring original measurement data of a region to be measured; 2, carrying out water area elevation processing, namely, performing elevation processing on a static water area and / or flowing water area in the region to be measured, wherein the static water area is processed as follows: 2011, judging level; 2012, processing the level, comprising the steps of I, extracting a bay line; II, assigning an elevation value on the bay line; and III, correcting the water level elevation; and the flowing water area is processed as follows: 2021, judging vertical adjustment; 2022, processing the vertical adjustment, comprising the steps of i, extracting a bay line; ii, assigning a bay line elevation and processing adjustment; iii, constructing an irregular triangular net and an interpolation water level elevation; and iv, correcting a water level elevation. The water area elevation processing method disclosed by the invention is simple in steps, reasonable in design, convenient to realize, good in use effect, and capable of simply and rapidly completing a water area elevation processing process with high quality; the made DEM is high in elevation precision.

The invention relates to an adaptive correction method for an intersection error of a surveying and mapping satellite. The method comprises: with random left and right visual stereo images of a same region, calculation of an affine transformation basis matrix F is put forward by using RPC parameters and SRTM data based on same-name point matching; on the basis of an SIFT algorithm, key point extraction, matching and optimization are carried out on the left and right visual stereo images, and calculation is performed to obtain a translation correction matrix T of an intersection error; after translation correction, a residual error reaches a sub-pixel level, so that the elevation precision is guaranteed effectively. According to the invention, intersection error correction is performed adaptively without a ground control point under the condition of a plurality of stereo images with different base-height ratios, so that the elevation accuracy of satellite surveying and mapping is improved substantially.

The invention provides an airborne interferometric synthetic aperture radar complex scene elevation inversion method and system, the method comprising: obtaining a plurality of single-view complex image pairs of the same complex scene to be detected at opposite angles in the fly-by-flight mode; All single-view complex image pairs obtain coordinate information in different coordinate systems of each single-view complex image pair, and each coordinate information contains a corresponding first height information; for each coordinate of all single-view complex image pairs Information, respectively mapped in the same coordinate system for coordinate conversion, to obtain each coordinate information after conversion and the second height information after conversion of the corresponding first height information; for each coordinate information after multiple coordinate conversions and the second height information The height information is gridded separately to generate each coordinate information containing the third height information; according to the preset fusion strategy, pixel fusion processing is performed on multiple coordinate information containing the third height information to generate the coordinate information of the complex scene to be detected. Highly inverted information.

The invention provides an associated high-precision positioning treatment method for single linear array satellite laser. The method comprises the following steps: using a single linear array satellite to swing along a track, using a set intersection angle to obtain a stereoscopic image of a ground target, and obtaining image space coordinates of corresponding image points through registration ofthe stereoscopic image; using initial orientation parameters and image coordinates of linear array images to calculate pass point initial matter square coordinates; carrying out registration on laser-measured height data and linear array images to obtain image space coordinates corresponding to laser points; constructing an error formula and a corresponding weight matrix; establishing a normal equation, answering image positioning model parameters and the correction numbers of pass point ground coordinates, and amending the image positioning model parameters and the pass point ground coordinates; calculating mean square errors, judging the difference between two mean square errors is smaller than a given limit error, carrying out iteration according to a judgment result, and outputting thecalculated image positioning model parameters and pass point ground coordinates. The data acquisition capacity also can be strengthened while the positioning accuracy is improved, and the timelinessof remote sensing information is guaranteed.