CN-121999068-A - Satellite optical imaging simulation method and device based on non-layered live-action three-dimensional model

CN121999068ACN 121999068 ACN121999068 ACN 121999068ACN-121999068-A

Abstract

The invention relates to a satellite optical imaging simulation method and device based on a non-layered live-action three-dimensional model, belonging to the technical field of remote sensing imaging simulation; simulating satellite imaging time, orbit position and satellite attitude to obtain a satellite linear array push broom imaging strict geometric model, fitting a rational function model to the strict geometric model to obtain an RPC model, carrying out ray tracing on the whole Jing Weixing image based on inter-block indexes, intra-block indexes and the RPC model to determine texture brightness information of ground points corresponding to pixels of the whole scene satellite image, carrying out illumination and shadow simulation based on the ground points to determine soft shadow intensity, and carrying out atmospheric transmission modeling and camera response modeling based on the texture brightness information and the soft shadow intensity to obtain the satellite optical simulation image. The simulation method provided by the invention can realize the rapid simulation of high-precision satellite optical imaging.

Inventors

ZUO ZHIQIANG
XIE GUANGQI
MA YUE
MA XIN
YE ZHIWEI
CHANG XUELI

Assignees

湖北工业大学

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (9)

1. The satellite optical imaging simulation method based on the non-layered live-action three-dimensional model is characterized by comprising the following steps of: Constructing an inter-block index and an intra-block index based on a plurality of OBJ block files corresponding to non-layered live-action three-dimensional model data; Simulating the satellite imaging time, the orbit position and the satellite attitude to obtain a strict geometric model of the satellite linear array push broom imaging, and fitting a rational function model to the strict geometric model to obtain an RPC model, wherein the strict geometric model and the RPC model are used for representing the instantaneous space relation among the ground feature point, the camera projection center and the image point; Performing ray tracing on the whole Jing Weixing image based on the inter-block index, the intra-block index and the RPC model, and determining texture brightness information of a ground point corresponding to a pixel of the whole scene satellite image; Performing illumination and shadow simulation based on the ground points, and determining soft shadow intensity; and carrying out atmosphere transmission modeling and camera response modeling based on the texture brightness information and the soft shadow intensity to obtain a satellite optical simulation image.
2. The satellite optical imaging simulation method based on the non-layered live-action three-dimensional model according to claim 1, wherein the constructing an inter-block index based on the plurality of OBJ block files corresponding to the non-layered live-action three-dimensional model data comprises: Analyzing the vertex coordinates of the OBJ blocking file, and determining a geographic range corresponding to the OBJ blocking file, wherein the geographic range comprises a longitude minimum value, a longitude maximum value, a latitude minimum value, a latitude maximum value and an altitude range; Packaging the geographical range, the file name, the file path, the number of top points and the number of triangular surfaces of the OBJ block file to obtain a block-level metadata entry; and constructing a global R tree index as the inter-block index based on the block-level metadata entry, and constructing a minimum circumscribed cube as an index key by using a model block coordinate range.
3. The satellite optical imaging simulation method based on the non-layered live-action three-dimensional model according to claim 1, wherein the constructing an intra-block index based on the plurality of OBJ block files corresponding to the non-layered live-action three-dimensional model data comprises: constructing a local geographic coordinate system by taking the geographic center of the model block corresponding to the OBJ block file as an origin; in the local geographic coordinate system, an initial cube space is built by taking 2 times of the length of the model block in the X-axis direction as the side length; recursively splitting the initial cube space to obtain a plurality of subcubes of spaces, wherein the number of triangular patches contained in each subcubes of spaces is smaller than or equal to a preset threshold value; And forming a multi-layer octree structure by taking the subcube space as a leaf node which is used for storing an index list of the triangular patches and a geographic bounding box of the leaf node.
4. The satellite optical imaging simulation method based on the non-layered live-action three-dimensional model according to claim 3, wherein the determining texture brightness information of the ground point corresponding to the pixel of the whole-view satellite image based on the inter-block index, the intra-block index and the RPC model by performing ray tracing on the whole Jing Weixing image comprises: dividing the whole scene image into a plurality of regular pixel blocks based on the RPC model, and determining leaf nodes corresponding to each pixel block by combining a digital elevation model; constructing three-dimensional space light rays starting from the pixels according to the maximum elevation and the minimum elevation corresponding to each pixel of the pixel block; Determining a live-action three-dimensional model block intersected with the three-dimensional space ray based on the inter-block index; traversing the intra-block indexes corresponding to the intersected live-action three-dimensional model blocks based on the three-dimensional space rays, and determining triangular patches corresponding to the pixels; and determining the texture brightness information based on the triangular patch corresponding to the pixel.
5. The method for simulating satellite optical imaging based on a non-layered live-action three-dimensional model according to claim 1, wherein the expression of the soft shadow intensities is as follows: Wherein, the Indicating the intensity of the soft shadow, Representing the number of shadow rays blocked by the three-dimensional model, Indicating the number of uniformly sampled sub-source points.
6. The satellite optical imaging simulation method based on the non-layered live-action three-dimensional model according to claim 1, wherein the performing atmospheric transmission modeling and camera response modeling based on the texture brightness information and the soft shadow intensity to obtain a satellite optical simulation image comprises: determining equivalent physical reflectivity of a sensor wave band based on the texture brightness information; Determining surface emergent radiance based on the sensor band equivalent physical reflectivity and the soft shadow intensity; Determining the entrance pupil brightness of the sensor based on the atmospheric path radiance and the surface exit radiance; Determining a dynamic ray vector based on the detector array inner row offset; Determining a static focal plane energy based on the sensor entrance pupil luminance and the dynamic ray vector; determining focal plane irradiance based on accumulated charge energy of the static focal plane energy; and mapping the focal plane irradiance into DN value to obtain the satellite optical simulation image.
7. A satellite optical imaging simulation device based on a non-layered live-action three-dimensional model, comprising: The construction unit is used for constructing inter-block indexes and intra-block indexes based on a plurality of OBJ block files corresponding to the non-layered live-action three-dimensional model data; the fitting unit is used for simulating the satellite imaging time, the orbit position and the satellite attitude to obtain a strict geometric model of the satellite linear array push-broom imaging, and performing rational function model fitting on the strict geometric model to obtain an RPC model, wherein the strict geometric model and the RPC model are used for representing the instantaneous space relation among the ground feature point, the camera projection center and the image point; The determining unit is used for carrying out ray tracing on the whole Jing Weixing image based on the inter-block index, the intra-block index and the RPC model, and determining texture brightness information of a ground point corresponding to a pixel of the whole scene satellite image; the simulation unit is used for carrying out illumination and shadow simulation based on the ground points and determining soft shadow intensity; and the simulation unit is used for carrying out atmosphere transmission modeling and camera response modeling based on the texture brightness information and the soft shadow intensity to obtain satellite optical simulation images.
8. An electronic device comprising a memory and a processor, wherein, The memory is used for storing programs; The processor is coupled to the memory for executing the program stored in the memory to implement the steps in the satellite optical imaging simulation method based on the non-hierarchical live-action three-dimensional model as set forth in any one of claims 1 to 6.
9. A computer readable storage medium storing a computer readable program or instructions which when executed by a processor is capable of carrying out the steps of the satellite optical imaging simulation method based on a non-layered live-action three-dimensional model as claimed in any one of claims 1 to 6.

Description

Satellite optical imaging simulation method and device based on non-layered live-action three-dimensional model Technical Field The invention relates to the technical field of remote sensing imaging simulation, in particular to a satellite optical imaging simulation method and device based on a non-layered live-action three-dimensional model. Background The remote sensing imaging simulation technology originates in the middle and later stages of the 20 th century and gradually develops along with the rising of satellite remote sensing technology. Early simulation studies focused mainly on simple geometric models and radiation transport theory for modeling the imaging effects of low resolution sensors (e.g., LANDSAT MSS). After the 80 s of the 20 th century, simulation methods began to introduce more complex physical models as computer graphics and monte carlo ray tracing techniques developed. However, these simulations are mostly dependent on low resolution digital elevation models (DEMs, such as SRTM) and two-dimensional images, such as satellite three-dimensional image simulations using digital elevation models, hyperspectral remote sensing images and digital orthophotos as input data, limited by computational power and wide range high precision data availability. The traditional simulation system is limited in application in high-precision tasks due to insufficient precision of input data, wherein ① multisource input data are insufficient in consistency, the DEM, remote sensing images and orthographic images are usually poor in geometric positioning precision, resolution and acquisition time, so that the positioning and radiation precision of the images are reduced after simulation, ② grid DSM data and orthographic image data cannot fully capture fine features and textures of complex terrains (such as buildings and steep slopes), the data precision and the spatial resolution are low, high-precision high-spatial resolution (such as 0.1m and 0.2 m) satellite imaging is difficult to simulate, ③ orthographic image data are based on a single orthographic view angle, three-dimensional world cannot be truly expressed, oblique view angles or multi-angle imaging of satellites during in-orbit is difficult to simulate, and precision and application simulation analysis under subsequent oblique imaging cannot be performed. In the 21 st century, with the wide application of high-resolution remote sensing satellites (such as IKONOS, worldView) and unmanned aerial vehicle platforms, higher requirements are put on the accuracy and the authenticity of imaging simulation. Traditional two-dimensional data and low-precision DEM can not accurately express complex surface features (such as urban building and mountain shielding), so that research is promoted to three-dimensional scene modeling. Meanwhile, the progress of unmanned aerial vehicle oblique photogrammetry technology makes the generation of a live-action three-dimensional model possible. Compared with the traditional digital surface model or two-dimensional image block, the real-scene three-dimensional model not only comprises three-dimensional geometric structures of terrains, buildings, vegetation and the like, but also fuses high-resolution real texture information (such as RGB, multispectral and even hyperspectral data). The models not only provide high-precision geometric structures, but also realize the true digital expression of the ground object through multi-source data fusion (such as multi-spectrum texture). The satellite platform and the remote sensing camera parameter design and optimization need to be quantitatively evaluated to ensure the imaging performance and geometric accuracy, and the actual flight test is high in cost and limited by environmental conditions, so that the satellite imaging simulation technology becomes an indispensable tool. Optimization of camera loading parameters (e.g., focal length, field angle) and shooting parameters (e.g., height, angle) depends on accurate imaging simulations. However, the traditional simulation method has insufficient performance under a complex scene, especially in urban environments or vegetation dense areas, and cannot accurately simulate the influence of shielding, shadows and visual angle changes on imaging. The simulation technology based on the high-precision three-dimensional model is generated, and the camera imaging process can be simulated more truly by introducing high-precision ground surface three-dimensional data, so that scientific basis is provided for load design and task planning. Conventional optical camera geometry imaging simulation systems are mostly based on digital earth surface models (low resolution terrain) or two-dimensional image blocks with lower precision, and these data sources have significant limitations in expressing the real three-dimensional world. Digital terrain data with lower spatial resolution is difficult to capture ground surface micro-fluctuation and building d