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Genauigkeitsuntersuchungen zur GPS/INS-Integration in der Aerophotogrammetrie / Michael Cramer (2001)

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Titre :	Genauigkeitsuntersuchungen zur GPS/INS-Integration in der Aerophotogrammetrie
Titre original :	[Recherches de l'exactitude pour l'intégration GPS/INS en photogrammétrie aérienne]
Type de document :	Thèse/HDR
Auteurs :	Michael Cramer, Auteur
Editeur :	Munich : Bayerische Akademie der Wissenschaften
Année de publication :	2001
Collection :	DGK - C
Sous-collection :	Dissertationen num. 537
Importance :	120 p.
Format :	21 x 30 cm
ISBN/ISSN/EAN :	978-3-7696-9576-2
Note générale :	Bibliographie
Langues :	Allemand (ger)
Descripteur :	[Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] aérotriangulation [Termes IGN] centrale inertielle [Termes IGN] élément d'orientation externe [Termes IGN] étalonnage de chambre métrique [Termes IGN] filtre de Kalman [Termes IGN] géoréférencement direct [Termes IGN] GPS-INS [Termes IGN] image aérienne [Termes IGN] orientation du capteur [Termes IGN] orientation externe [Termes IGN] point de vérification [Termes IGN] précision de localisation [Termes IGN] prise de vue aérienne [Termes IGN] recouvrement d'images
Index. décimale :	33.30 Photogrammétrie numérique
Résumé :	(Auteur) Within this thesis different approaches for the direct measurement of exterior orientation elements of airborne sensors using integrated GPS/INS modules are investigated. The main focus is laid on the analysis of the accuracy potential of a commercially available integrated GPS/INS module using the "standard" approach for direct georeferencing : the integration of continuously recorded GPS and INS data in a Kalman filter approach. This method, originally developed for navigation purposes, is compared to a more straightforward strip-wise approach, which allows, in combination with an imaging sensor, the direct orientation determination even for short time intervals and data segments during photogrammetric strips. Beforehand, the basic principles of GPS/INS integration and the different system-characteristics of GPS and INS are summarized. The two different approaches for GPS/INS integration mentioned before are investigated on their accuracy performance. For the accuracy analysis the GPS/INS module was combined with a standard analogue aerial camera and flown over a well controlled photogrammetric test site. Utilizing the standard approach of indirect image orientation applying the method of aerial triangulation independent exterior orientations for the discrete camera air stations are obtained and can be used for the estimation of the accuracy potential from GPS/INS. For tile tested commercial GPS/INS module the obtained quality of directly measured orientation elements in an operational airborne environment was about ~10cm for the positioning and ~15” for the attitude. Using the GPS/INS exterior orientations for direct georeferencing without ground control an accuracy of about 8-11µm and 15-23µm in image space is obtained for horizontal and vertical components, respectively. Transferring the accuracy on medium scale photo flight from an altitude of about 2000m above ground, object points are determined with an accuracy of 10-20cm for the horizontal and 20-30cm for the vertical coordinates. This accuracy even holds for the photogrammetrically problematic case of single flight lines. The use of stronger image overlap is of positive influence on the quality of object point determination. Using the second approach of strip-wise GPS/INS evaluation in a combined AT approach similar accuracy is obtained from the same data set. Therefore, this approach offers an alternative orientation method for imaging sensors in case of non-continuously recorded INS data. The accuracy potential of GPS/INS integration is dependent on the quality of the used sensors and the quality of the GPS update information. The influence of the remaining errors in GPS/INS positions and attitudes on the object point determination is related on the actual flying height. For large scale imagery recorded from lower altitudes positioning errors are of major influence, whereas for higher altitudes remaining attitude errors are the main part of the error budget. Additionally, the overall system quality including the GPS/INS orientation components and the imaging sensor is strongly dependent on the correct overall system calibration. Within this context system calibration is not only restricted on the correct determination of the time and spatial eccentricities between the different sensor components but the calibration of the imaging sensor itself is of major importance. Since there is no possibility of subsequent self-calibration in direct georeferencing, every difference between the assumed mathematical model and the true physical environment during data recording will cause errors in object space. Within the analyzed data set scale dependent errors in the vertical coordinate are present. which could be modelled by slightly modifying the camera focal length used for data evaluation. The obtained empirical accuracy is of major interest for the subsequent operational use of direct georeferencing in a standard photogrammetric environment. Due to this, the GPS/INS orientation accuracy is calculated using different baseline lengths between aircraft and reference station and varying image overlap and block geometry. Additionally, the influence of interpolation errors on varying data rates used for GPS/INS trajectory computations is estimated. Against the background of direct georeferencing using GPS/INS in photogrammetric practice - without ground control in the ideal case - the overall system requirements are discussed. In the final part of this thesis the possible future use of direct GPS/INS orientation measurements in photogrammetric practice is pointed out.
Numéro de notice :	27826
Affiliation des auteurs :	non IGN
Thématique :	IMAGERIE
Nature :	Thèse étrangère
DOI :	sans
En ligne :	https://www.ifp.uni-stuttgart.de/dokumente/Dissertationen/Cramer_Diss.pdf
Format de la ressource électronique :	URL
Permalink :	https://documentation.ensg.eu/index.php?lvl=notice_display&id=56450

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
27826-02	33.30	Livre	Centre de documentation	Photogrammétrie - Lasergrammétrie	Disponible
27826-01	33.30	Livre	Centre de documentation	Photogrammétrie - Lasergrammétrie	Disponible

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2014 -2024 IGN

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scientifique