ILRS Reference Point Determination Using Close Range Photogrammetry
A global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of...
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MDPI AG
2021-03-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/6/2785 |
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| author | Michael Lösler Cornelia Eschelbach Thomas Klügel Stefan Riepl |
| author_facet | Michael Lösler Cornelia Eschelbach Thomas Klügel Stefan Riepl |
| author_sort | Michael Lösler |
| collection | DOAJ |
| description | A global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of such a realization. Due to the weak physical connection between the space geodetic techniques, so-called local ties are introduced to the combination procedure. A local tie is the spatial vector defined between the reference points of two space geodetic techniques. It is derivable by local measurements at multitechnique stations, which operate more than one space geodetic technique. Local ties are a crucial component within the intertechnique combination; therefore, erroneous or outdated vectors affect the global results. In order to reach the ambitious accuracy goal of 1 mm for a global position, the global geodetic observing system (GGOS) aims for strategies to improve local ties, and, thus, the reference point determination procedures. In this contribution, close range photogrammetry is applied for the first time to determine the reference point of a laser telescope used for satellite laser ranging (SLR) at Geodetic Observatory Wettzell (GOW). A measurement campaign using various configurations was performed at the Satellite Observing System Wettzell (SOS-W) to evaluate the achievable accuracy and the measurement effort. The bias of the estimates were studied using an unscented transformation. Biases occur if nonlinear functions are replaced and are solved by linear substitute problems. Moreover, the influence of the chosen stochastic model onto the estimates is studied by means of various dispersion matrices of the observations. It is shown that the resulting standard deviations are two to three times overestimated if stochastic dependencies are neglected. |
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| format | Article |
| id | doaj.art-b29f2d1d694c492daf0c3a8b4a585cfb |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T13:04:08Z |
| publishDate | 2021-03-01 |
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| series | Applied Sciences |
| spelling | doaj.art-b29f2d1d694c492daf0c3a8b4a585cfb2023-11-21T11:18:17ZengMDPI AGApplied Sciences2076-34172021-03-01116278510.3390/app11062785ILRS Reference Point Determination Using Close Range PhotogrammetryMichael Lösler0Cornelia Eschelbach1Thomas Klügel2Stefan Riepl3Laboratory of Industrial Metrology, Faculty 1: Architecture · Civil Engineering · Geomatics, Frankfurt University of Applied Sciences, 60318 Frankfurt, GermanyLaboratory of Industrial Metrology, Faculty 1: Architecture · Civil Engineering · Geomatics, Frankfurt University of Applied Sciences, 60318 Frankfurt, GermanyGeodetic Observatory Wettzell, Federal Agency for Cartography and Geodesy, 93444 Bad Kötzting, GermanyGeodetic Observatory Wettzell, Federal Agency for Cartography and Geodesy, 93444 Bad Kötzting, GermanyA global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of such a realization. Due to the weak physical connection between the space geodetic techniques, so-called local ties are introduced to the combination procedure. A local tie is the spatial vector defined between the reference points of two space geodetic techniques. It is derivable by local measurements at multitechnique stations, which operate more than one space geodetic technique. Local ties are a crucial component within the intertechnique combination; therefore, erroneous or outdated vectors affect the global results. In order to reach the ambitious accuracy goal of 1 mm for a global position, the global geodetic observing system (GGOS) aims for strategies to improve local ties, and, thus, the reference point determination procedures. In this contribution, close range photogrammetry is applied for the first time to determine the reference point of a laser telescope used for satellite laser ranging (SLR) at Geodetic Observatory Wettzell (GOW). A measurement campaign using various configurations was performed at the Satellite Observing System Wettzell (SOS-W) to evaluate the achievable accuracy and the measurement effort. The bias of the estimates were studied using an unscented transformation. Biases occur if nonlinear functions are replaced and are solved by linear substitute problems. Moreover, the influence of the chosen stochastic model onto the estimates is studied by means of various dispersion matrices of the observations. It is shown that the resulting standard deviations are two to three times overestimated if stochastic dependencies are neglected.https://www.mdpi.com/2076-3417/11/6/2785close range photogrammetrybundle adjustmentreference point determinationunscented transformationstochastic modelsatellite laser ranging |
| spellingShingle | Michael Lösler Cornelia Eschelbach Thomas Klügel Stefan Riepl ILRS Reference Point Determination Using Close Range Photogrammetry Applied Sciences close range photogrammetry bundle adjustment reference point determination unscented transformation stochastic model satellite laser ranging |
| title | ILRS Reference Point Determination Using Close Range Photogrammetry |
| title_full | ILRS Reference Point Determination Using Close Range Photogrammetry |
| title_fullStr | ILRS Reference Point Determination Using Close Range Photogrammetry |
| title_full_unstemmed | ILRS Reference Point Determination Using Close Range Photogrammetry |
| title_short | ILRS Reference Point Determination Using Close Range Photogrammetry |
| title_sort | ilrs reference point determination using close range photogrammetry |
| topic | close range photogrammetry bundle adjustment reference point determination unscented transformation stochastic model satellite laser ranging |
| url | https://www.mdpi.com/2076-3417/11/6/2785 |
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