LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS

The possibility of equipping UAVs with lightweight GNSS receivers in order to estimate the camera position within a photogrammetric block allows for a reduction of the number of Ground Control Points (GCP), saving time during the field work and decreasing operational costs. Additionally, this makes...

Full description

Bibliographic Details
Main Authors: F. Ioli, L. Pinto, F. Ferrario
Format: Article
Language:English
Published: Copernicus Publications 2021-06-01
Series:The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Online Access:https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLIII-B2-2021/25/2021/isprs-archives-XLIII-B2-2021-25-2021.pdf
_version_ 1818848410098204672
author F. Ioli
L. Pinto
F. Ferrario
author_facet F. Ioli
L. Pinto
F. Ferrario
author_sort F. Ioli
collection DOAJ
description The possibility of equipping UAVs with lightweight GNSS receivers in order to estimate the camera position within a photogrammetric block allows for a reduction of the number of Ground Control Points (GCP), saving time during the field work and decreasing operational costs. Additionally, this makes it possible to build photogrammetric models even in morphologically complex areas or in emergency situations. This work is proposing a non-intrusive and low-cost procedure to retrieve the coordinates of the camera projection centre with decimetric accuracy. The method was designed and tested with the quadcopter DJI Matrice 210 V2 drone equipped with a DJI ZENMUSE X5S camera and an Emlid reach M, a low-cost, single-frequency (L1) GNSS receiver. GNSS observations are post-processed in PPK in order to obtain the UAV trajectory. Synchronization between the camera and the GNSS receiver is achieved by looking at the camera triggering timestamps in flight telemetry data, without requiring an electronic connection between camera and the GNSS that may be troublesome with commercial UAVs. Two surveys were carried out, respectively to calibrate and validate the procedure. The validation test evidenced the possibility of obtaining the coordinates of the camera projection centres with decimetric accuracy. The centre of projections can then be employed for GNSS-assisted aerial triangulation as input of the bundle block adjustment. Provided that at least one GCP is used, it is possible to reach centimetric accuracy on the ground.
first_indexed 2024-12-19T06:16:54Z
format Article
id doaj.art-6f9d8dd71c25458bbf6db8cc0f89d70f
institution Directory Open Access Journal
issn 1682-1750
2194-9034
language English
last_indexed 2024-12-19T06:16:54Z
publishDate 2021-06-01
publisher Copernicus Publications
record_format Article
series The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
spelling doaj.art-6f9d8dd71c25458bbf6db8cc0f89d70f2022-12-21T20:32:50ZengCopernicus PublicationsThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences1682-17502194-90342021-06-01XLIII-B2-2021253210.5194/isprs-archives-XLIII-B2-2021-25-2021LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVSF. Ioli0L. Pinto1F. Ferrario2Department of Civil and Environmental Engineering (DICA), Politecnico di Milano, ItalyDepartment of Civil and Environmental Engineering (DICA), Politecnico di Milano, ItalyDepartment of Civil and Environmental Engineering (DICA), Politecnico di Milano, ItalyThe possibility of equipping UAVs with lightweight GNSS receivers in order to estimate the camera position within a photogrammetric block allows for a reduction of the number of Ground Control Points (GCP), saving time during the field work and decreasing operational costs. Additionally, this makes it possible to build photogrammetric models even in morphologically complex areas or in emergency situations. This work is proposing a non-intrusive and low-cost procedure to retrieve the coordinates of the camera projection centre with decimetric accuracy. The method was designed and tested with the quadcopter DJI Matrice 210 V2 drone equipped with a DJI ZENMUSE X5S camera and an Emlid reach M, a low-cost, single-frequency (L1) GNSS receiver. GNSS observations are post-processed in PPK in order to obtain the UAV trajectory. Synchronization between the camera and the GNSS receiver is achieved by looking at the camera triggering timestamps in flight telemetry data, without requiring an electronic connection between camera and the GNSS that may be troublesome with commercial UAVs. Two surveys were carried out, respectively to calibrate and validate the procedure. The validation test evidenced the possibility of obtaining the coordinates of the camera projection centres with decimetric accuracy. The centre of projections can then be employed for GNSS-assisted aerial triangulation as input of the bundle block adjustment. Provided that at least one GCP is used, it is possible to reach centimetric accuracy on the ground.https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLIII-B2-2021/25/2021/isprs-archives-XLIII-B2-2021-25-2021.pdf
spellingShingle F. Ioli
L. Pinto
F. Ferrario
LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
title LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
title_full LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
title_fullStr LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
title_full_unstemmed LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
title_short LOW-COST DGPS ASSISTED AERIAL TRIANGULATION FOR SUB-DECIMETRIC ACCURACY WITH NON-RTK UAVS
title_sort low cost dgps assisted aerial triangulation for sub decimetric accuracy with non rtk uavs
url https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLIII-B2-2021/25/2021/isprs-archives-XLIII-B2-2021-25-2021.pdf
work_keys_str_mv AT fioli lowcostdgpsassistedaerialtriangulationforsubdecimetricaccuracywithnonrtkuavs
AT lpinto lowcostdgpsassistedaerialtriangulationforsubdecimetricaccuracywithnonrtkuavs
AT fferrario lowcostdgpsassistedaerialtriangulationforsubdecimetricaccuracywithnonrtkuavs