Landsat TM imagery is being used to monitor landcover change in a number of operational projects in Australia. Most recently, the Australian Greenhouse Office (AGO) has undertaken a project to provide historical monitoring of changes in woody vegetation across the continent. In order to map and monitor landcover changes in a consistent and comparable manner across broad areas, it is highly desirable to have a consistently calibrated numerical base. To this end, the AGO has supported the creation of a rectification and calibration base for Australia, using Landsat TM data; 369 Landsat 7 images from the period July 1999 to September 2000 were purchased from the Australian Centre for Remote Sensing (ACRES). This paper describes the processing and production of the calibration base from these images.
This paper gives a brief description of the method and techniques developed for the modeling and reconstruction of fast moving and deforming 3D objects. A new approach using close-range digital terrestrial photogrammetry in conjunction with high speed photography and videography is proposed. A sequential image matching method (SIM) has been developed to automatically process pairs of images taken continuously of any fast moving and deforming 3D objects. Using the SIM technique a temporal-spatial model (TSM) of any fast moving and deforming 3D objects can be developed. The TSM would include a series of reconstructed surface models of the fast moving and deforming 3D object in the form of 3D images. The TSM allows the 3D objects to be visualized and analyzed in sequence. The SIM method, specifically the left-right matching and forward-back matching techniques are presented in the paper. An example is given which deals with the monitoring of a typical blast rock bench in a major open pit mine in Australia. With the SIM approach and the TSM model it is possible to automatically and efficiently reconstruct the 3D images of the blasting process. This reconstruction would otherwise be impossible to achieve using a labor intensive manual processing approach based on 2D images taken from conventional high speed cameras. The case study demonstrates the potential of the SIM approach and the TSM for the automatic identification, tracking and reconstruction of any fast moving and deforming 3D targets.
This paper describes one of the industrial applications of our digital photogrammetric system VirtuoZo, namely a prototype system to collect 3D data from stereo-video pair sequences along a rail road track for clearance measurements. With the rapid developing of digital media such as charge-coupled-device (CCD) and digital video cameras, stereo images pairs can be captured in a much easier and faster way compared with traditional means. Digital photogrammetry can thus now be used in many new applications. However, with the geometry of CCD (or digital video) cameras different from the classic analogy metric camera, new relative orientation and epipolar image resampling algorithms have to be developed for these nonmetric cameras. An example of such a new application is given in this paper: a series of sequential stereo image pairs were captured by two digital cameras along a railway track from a moving rail platform, then relative orientation was done fully automatically by matching registering points in the two stereo scenes using a hierarchical relaxation image matching algorithm. Then, epipolar images are resampled from the original images by means of a relative linear transform, and finally a 3D data collection algorithm allows a user-friendly interface to the human operator for data capture on a SGI workstation under StereoView.
A digital photogrammetric workstation system is developed in P.R. China which performed automatic mapping from space imagery data efficiently. Since the earlier periods of space programs, surveyors and cartographers have been looking forward to the day when imagery data obtained from space can be utilized in mapping. With the launched and launching satellites, such as SPOT, MOMS, ERS-1, Radarset, etc., especially the announcement of Eyeglass, people are more interested in mapping using space imagery directly. This paper first compares two stereo imagery mapping methods (traditional photogrammetry and digital photogrammetry), then discuss the theory and practice in details in stereo viewing and automatic stereo measurement (image matching) of stereo imagery by Digital Photogrammetric Workstation.
A digital photogrammetric workstation is a digital stereoplotter based on digital stereo images for various photogrammetric applications. Digital photogrammetry has reached a practical degree. Most of its technical problems for extraction of terrain information have been solved. Its workstation is available and affordable, and has the capabilities to produce all types of conventional photogrammetric products, as well as some new products, such as perspective scenes and animated landscapes. In the past fifteen years, a digital photogrammetric workstation named WuDAMS (Wuhan's Digital Automatic Mapping System) has been installed in WTUSM (Wuhan Technical University of Surveying and Mapping), Wuhan, P. R. China. In this paper, the hardware, the software, the theoretic foundation, and potential applications of WuDAMs are introduced. The photogrammetric workflow, flexibility, ease-of- use, and accuracy of WuDAMS are also outlined.