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航弹SINS/GPS组合导航系统半实物仿真试验设计  [PDF]
北京理工大学学报 , 2004,
Abstract: 针对某型远程航空弹药SINS/GPS组合导航系统的组成,设计了SINS/GPS组合导航的半实物仿真试验框架结构,探讨了在试验过程中多机时钟同步的问题,检验了捷联惯导系统导航计算机的解算性能和GPS信息的修正效果.试验结果表明,捷联惯导系统的算法正确,解算精度和解算时延满足控制系统的要求,GPS信息修正效果良好,SINS/GPS组合导航系统可以应用到航空弹药的制导与控制系统中.
Qualitative and quantitative photogrammetric techniques for multi-temporal landslide analysis  [cached]
A. Zanutta,P. Baldi,G. Bitelli,M. Cardinali
Annals of Geophysics , 2006, DOI: 10.4401/ag-3117
Abstract: The results of two survey methods, geological photointerpretation and historical photogrammetry, are compared in order to evaluate the temporal evolution of a unstable slope located in the Tuscan-Emilian Apennines (Italy). Historical aerial photos of the area, derived from photogrammetric surveys conducted in 1954 (scale 1:60000), in 1971 (scale 1:20000), and in 1976 (scale 1:17000) were available. A photogrammetric flight was further conducted in 2000, at a scale of 1:4400, with a traditional GPS ground survey support. First, the results of photographic analysis with the photointerpretation method are presented: the landslides are described from a geological point of view, showing its temporal evolution. To quantitatively assess the landslide movements, Digital Terrain Models were generated by means of an analytical plotter and a digital photogrammetric workstation, with semi-automatic and automatic procedures. To generate these products, it was necessary to solve problems related to a lack of data concerning the aerial cameras used for the historical flights (internal orientation) and the difficulty identifying control points on the photos in order to define the external orientation. An unconventional photogrammetric methodology, based on identification of homologous points in zones considered outside the landslide area, has been there developed and tested to insert the various surveys into a single reference system.
Calibration of Action Cameras for Photogrammetric Purposes  [PDF]
Caterina Balletti,Francesco Guerra,Vassilios Tsioukas,Paolo Vernier
Sensors , 2014, DOI: 10.3390/s140917471
Abstract: The use of action cameras for photogrammetry purposes is not widespread due to the fact that until recently the images provided by the sensors, using either still or video capture mode, were not big enough to perform and provide the appropriate analysis with the necessary photogrammetric accuracy. However, several manufacturers have recently produced and released new lightweight devices which are: (a) easy to handle, (b) capable of performing under extreme conditions and more importantly (c) able to provide both still images and video sequences of high resolution. In order to be able to use the sensor of action cameras we must apply a careful and reliable self-calibration prior to the use of any photogrammetric procedure, a relatively difficult scenario because of the short focal length of the camera and its wide angle lens that is used to obtain the maximum possible resolution of images. Special software, using functions of the OpenCV library, has been created to perform both the calibration and the production of undistorted scenes for each one of the still and video image capturing mode of a novel action camera, the GoPro Hero 3 camera that can provide still images up to 12 Mp and video up 8 Mp resolution.
The Effect of Scanning Resolution in Digital Photogrammetric Workstation
E.M. Elhadi,Hu .Guangdao,N. Zomrawi
Journal of Engineering and Applied Sciences , 2012,
Abstract: Pixel resolution is one of the main factors that affecting the final result in digital photogrammetry in general and in digital photogrammetric workstation in particular. An aerial wide-angle hard copy stereo pair was transformed to a soft copy using different scanning resolution by special photogrammetric scanner. Digital photogrammetric workstation was used to measure a number of control points of a known ground coordinates. ERDAS package was used to digitally rectify the scanned images using the same pixel resolution used above. And the coordinates of points were measured again. The results of this investigations proof that the accuracy of the measurements in digital photogrammetry is proportional to scanning pixel resolution in both horizontal and vertical measurements. And mathematical models were developed to estimate the accuracy via scanning resolution and suitable plotting scale in both horizontal and vertical mapping. Production of maps using digital image rectification using software packages such as ERDAS is suitable only in flat terrain. And digital photogrammetric workstation is a productive way for mapping in all flat and mountainous terrain.
Application of stereo photogrammetric techniques for measuring African Elephants  [cached]
A. J Hall-Martin,H Ruther
Koedoe : African Protected Area Conservation and Science , 1979, DOI: 10.4102/koedoe.v22i1.658
Abstract: Measurements of shoulder height and back length of African elephants were obtained by means of stereo photogrammetric techniques. A pair of Zeiss UMK 10/1318 cameras, mounted on a steel frame on the back of a vehicle, were used to photograph the elephants in the Addo Elephant National Park, Republic of South Africa. Several modifications of normal photogrammetry procedure applicable to the field situation (eg. control points) and the computation of results (eg. relative orientation) are briefly mentioned. Six elephants were immobilised after being photographed and the measurements obtained from them agreed within a range of 1 cm-10 cm with the photogrammetric measurements.
A Photogrammetric Approach for Assessing Positional Accuracy of OpenStreetMap? Roads  [PDF]
Roberto Canavosio-Zuzelski,Peggy Agouris,Peter Doucette
ISPRS International Journal of Geo-Information , 2013, DOI: 10.3390/ijgi2020276
Abstract: As open source volunteered geographic information continues to gain popularity, the user community and data contributions are expected to grow, e.g., CloudMade, Apple, and Ushahidi now provide OpenStreetMap ? (OSM) as a base layer for some of their mapping applications. This, coupled with the lack of cartographic standards and the expectation to one day be able to use this vector data for more geopositionally sensitive applications, like GPS navigation, leaves potential users and researchers to question the accuracy of the database. This research takes a photogrammetric approach to determining the positional accuracy of OSM road features using stereo imagery and a vector adjustment model. The method applies rigorous analytical measurement principles to compute accurate real world geolocations of OSM road vectors. The proposed approach was tested on several urban gridded city streets from the OSM database with the results showing that the post adjusted shape points improved positionally by 86%. Furthermore, the vector adjustment was able to recover 95% of the actual positional displacement present in the database. To demonstrate a practical application, a head-to-head positional accuracy assessment between OSM, the USGS National Map (TNM), and United States Census Bureau’s Topologically Integrated Geographic Encoding Referencing (TIGER) 2007 roads was conducted.
Development of Photogrammetric Methods of Stress Analysis and Quality Control  [PDF]
Donna L. Kubik,John A. Greenwood
Physics , 2003,
Abstract: A photogrammetric method of stress analysis has been developed to test thin, nonstandard windows designed for hydrogen absorbers, major components of a muon cooling channel. The purpose of the absorber window tests is to demonstrate an understanding of the window behavior and strength as a function of applied pressure. This is done by comparing the deformation of the window, measured via photogrammetry, to the deformation predicted by finite element analysis (FEA). FEA analyses indicate a strong sensitivity of strain to the window thickness. Photogrammetric methods were chosen to measure the thickness of the window, thus providing data that are more accurate to the FEA. This, plus improvements made in hardware and testing procedures, resulted in a precision of 5 microns in all dimensions and substantial agreement with FEA predictions.
Photogrammetric determination of the spatial shape of the clinker silo  [PDF]
Marek Fra?tia,Marek Bajtala,?tefan Sokol
Acta Montanistica Slovaca , 2007,
Abstract: Digital photogrammetry, in comparison with analogue or analytical, streamlines whole process of determination of a spatial point position, whether time reduction or increasing of accuracy. In this sense, a amateur digital cameras can be used for purposes of accurate measurement of objects by the method of stereophotogrammetry or convergent photography. The paper is aimed at using of the close-range photogrammetry for a spatial shape determination of the steel coating of the clinker silo and at a comparison of the photogrammetric and geodetic results.
?elimir Ortolan,Jonatan Ple?ko
Rudarsko-Geolo?ko-Naftni Zbornik , 1992,
Abstract: Repeated photogrammetric measurements are a valuable source of conserved information during final shaping of geotechnical models of complex multi-layer landslides. Photogrammetric measurements of a sequence of detailed unchanged points enable establishing the clear limit between the moved and stable parts of the terrain. The paper provides a number of practical and theoretical findings resulting from an adequate interpretation of photogrammetric measurements made on a thoroughly analyzed landslide where a three-level slide was observed. The results obtained indicate that the method used in this paper should be adopted as a standard procedure.
gps/dr原始观测值组合导航定位研究  [PDF]
武汉大学学报(信息科学版) , 2009,
Abstract: ?根据gps/dr组合系统的导航定位原理,推导了利用gps原始观测值与dr航位推算信息进行组合的kalman滤波模型,并利用该滤波模型对gps/dr原始观测数据进行航位解算。数据处理结果表明,即使在只有两颗gps观测卫星的情况下,该滤波模型也可以充分利用gps观测信息提高dr航位推算精度。
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