A tilt photography Brief
Tilt photography is an international high-tech mapping remote sensing developed in recent years, it has broken the limitations of the previous orthophoto can only be taken from a perpendicular angle, by carrying multiple sensors on the same flight platform, while the vertical tilt different angles to capture images, access ground objects more complete and accurate information. Perpendicular to the ground angle shot image acquired called positive lens toward the ground at an angle of captured image acquired called swash plate.
Second, process modeling techniques inclined photography
1, image acquisition inclined
Tilt photography is not only different from the traditional vertical aerial photography in the photography mode, and the results of its post-data processing is also very different. The main purpose of the tilt feature photography is to obtain a plurality of orientations (especially side) of the information available to users and multi-angle view, real-time measurements, to obtain a three-dimensional browsing and other aspects of information.
(1) an inclined imaging system configuration
Inclined imaging system divided into three parts, the first part is a flying platform; the second part the art; third part portion instruments, sensors (long cameras, GPS positioning means acquires three-line exposure elements instantaneous x, y, z) and attitude positioning system (attitude instant recording camera exposure, three diagonal elements φ, ω, κ).
(2) slant route design photography
Tilt photography course designed using special route design software to design, its relatively high flight, ground resolution and pixel size to meet the physical triangle proportional relationship. Route design in general, the next to reach 60-80% degree of overlap, of course overlap reach 60-80%. Pos route design software to generate a data file that includes an exposure point coordinate position and an actual camera plane flying attitude angle data corresponding to the respective camera, three-dimensional modeling of the data base to add location information and the angle calculated on the basis of data.
2, the image processing tilt
After image acquisition is completed, the first image to be acquired of the quality checks of the failed area fly up, until the image quality to meet the requirements acquired; Secondly dodging uniform color processing; geometric correction again, matching points of the same name, region net adjustment, the final data (three three coordinate information and the direction angle information) of the image of each tilt adjustment imparted, so that their position and attitude data having virtual three-dimensional space, the image can be inclined so far real-time measurements, each pixel on the diagonal segments each corresponding to a real geographic coordinates of the location. Tilt photography modeling techniques typically include:
(1) pre-processing the image; (2) Joint adjustment area network; (3) multi-view image density matching; (4) Digital Surface Model (DSM) production; (5) correcting the real orthophoto. Key elements of its basic principles as follows:
Third, the tilt model production
Obliquely inclined photographic image acquired after the image model generating processing may be performed. The main technical modeling method:
Tilt photography automated modeling, only the production model by tilting the multi-view images obtained in photography, namely Mesh (TIN) model. Process automation model can be simply described as follows: After the first geometric correction, a series of complex joint adjustment calculation to obtain the point cloud data with dense elevation, thinning, and then build a continuous TIN DEM, and finally scores of shooting video posted online triangular, end up tilting photography model, as shown below.
Fourth, the tilt photography applications
Tilt photography technology development not only expands the applications of remote sensing and photogrammetry technology, the introduction of the technology also makes the cost of 3D city modeling is greatly reduced. Currently, tilt photography technique is widely used in urban management, areas of land and resources management, smart city, emergency command, homeland security, geological prevention. Following is a brief application of three-dimensional modeling photography in landslide control project in the next tilt.
1, real all-round display
Tilt photography is a three-dimensional model of the relationship between real model, and the like surface attachments very precise structures, surface texture and color etc. consistent with the actual situation. By browsing dioramas, you can easily understand the entire scope of the project, forming a visual impression of the whole project.
2, real-time measurement
High precision three-dimensional model oblique photography, 0.05M resolution better than the model, and may be directly based model includes a height, length, area, angle of slope equal measure.
3, a powerful profile analysis function
Three-dimensional model of the actual photography inclined surface covering a three-dimensional elevation grid line accurate images from the surface through a dedicated software, can easily cross-sectional surface taken, to facilitate targeted analysis.
4, three-dimensional design features
Using special software, can easily tilt photography three-dimensional model of three-dimensional design, the image of the project management directly reflected in the three-dimensional model, it can be more accurately calculate the amount of engineering excavation and backfill parties, but also can be a simple crash test and optimize design.
Fifth, we have knowledge of the development of the industry
1, data, platforms, services are the three main content of the future geographic information industry, the trend is the production of integrated data intensive applications and services;
2, the data content from the two-dimensional plane extended to "on the ground - underground, indoor - outdoor" integration of three-dimensional space, and increase the time dimension;
3, who has mastered the full three-dimensional data elements, who will occupy the commanding heights of the three-dimensional industry;
4, with a fine, measurable, realistic, high-precision, object-oriented, faster updates, customized three-dimensional geographic information industry will become the basis for application support and public services;
5, in the big data era, the era of smart city, holographic three-dimensional geographic information industry will serve the smart city, a powerful weapon for big data era.