Geometric Calibration of an Aerial Multihead Camera System for Direct Georeferencing Applications

Filho, Leonardo Ercolin; Mitishita, Edson Aparecido; Kersting, Ana Paula

doi:10.1109/jstars.2017.2666298

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…A compromise can be found by using medium format cameras. They can be implemented in production the same way as large format cameras, with only a small loss of accuracy [25]. Experiences in close-range photogrammetry prove that industrial cameras are becoming more stable [26].…”

Section: State Of the Art In Camera Calibrationmentioning

confidence: 99%

Calibration of Industrial Cameras for Aerial Photogrammetric Mapping

et al. 2020

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This paper details the development of a camera calibration method purpose-built for use in photogrammetric survey production. The calibration test field was established in a hangar, where marker coordinates were measured using a high-precision survey methodology guaranteeing very high accuracy. An analytical model for bundle adjustment was developed that does not directly use the coordinates of field calibration markers but integrates bundle adjustment and survey observations into a single process. This solution, as well as a classical calibration method, were implemented in a custom software, for which the C++ source code repository is provided. The method was tested using three industrial cameras. The comparison was drawn towards a baseline method, OpenCV implementation. The results point to the advantages of using the proposed approach utilizing extended bundle adjustment.

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Section: State Of the Art In Camera Calibrationmentioning

confidence: 99%

Calibration of Industrial Cameras for Aerial Photogrammetric Mapping

et al. 2020

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“…The investigation showed the advantages of using direct sensor orientation for image georeferencing without ground control points and independent of block or strip configurations. Filho et al [ 32 ] presented an in-flight calibration method for multi-head camera systems, and the applications of direct georeferencing were evaluated.…”

Section: Introductionmentioning

confidence: 99%

Direct Georeferencing for the Images in an Airborne LiDAR System by Automatic Boresight Misalignments Calibration

Liu

et al. 2020

Sensors

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Airborne Light Detection and Ranging (LiDAR) system and digital camera are usually integrated on a flight platform to obtain multi-source data. However, the photogrammetric system calibration is often independent of the LiDAR system and performed by the aerial triangulation method, which needs a test field with ground control points. In this paper, we present a method for the direct georeferencing of images collected by a digital camera integrated in an airborne LiDAR system by automatic boresight misalignments calibration with the auxiliary of point cloud. The method firstly uses an image matching to generate a tie point set. Space intersection is then performed to obtain the corresponding object coordinate values of the tie points, while the elevation calculated from the space intersection is replaced by the value from the LiDAR data, resulting in a new object point called Virtual Control Point (VCP). Because boresight misalignments exist, a distance between the tie point and the image point of VCP can be found by collinear equations in that image from which the tie point is selected. An iteration process is performed to minimize the distance with boresight corrections in each epoch, and it stops when the distance is smaller than a predefined threshold or the total number of epochs is reached. Two datasets from real projects were used to validate the proposed method and the experimental results show the effectiveness of the method by being evaluated both quantitatively and visually.

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