FN Archimer Export Format
PT J
TI UAV survey of a coastal cliff face - Selection of the best imaging angle
BT 
AF JAUD, Marion
   LETORTU, Pauline
   THERY, Claire
   GRANDJEAN, Philippe
   COSTA, Stephane
   MAQUAIRE, Olivier
   DAVIDSON, Robert
   LE DANTEC, Nicolas
AS 1:1;2:2;3:2;4:3;5:4;6:4;7:4;8:5,6;
FF 1:;2:;3:;4:;5:;6:;7:;8:;
C1 Univ Bretagne Occidentale, IUEM, CNRS, UMS 3113,Technopole Brest Iroise, Rue Dumont dUrville, F-29280 Plouzane, France.
   Univ Bretagne Occidentale, IUEM, CNRS, UMR 6554,LETG,Technopole Brest Iroise, Rue Dumont dUrville, F-29280 Plouzane, France.
   Univ Lyon 1, CNRS, UMR 5276, Lab Geol Lyon, 2 Rue Raphael Dubois,Batiment GEODE, F-69622 Villeurbanne, France.
   Normandie Univ, UNICAEN, CNRS, UMR 6554,LETG, F-14000 Caen, France.
   Cerema, Direct Eau Mer & Fleuves, 134 Rue Beauvais, F-60280 Margny Les Compiegne, France.
   Univ Bretagne Occidentale, IUEM, CNRS, UMR 6538,Geosci Ocean,Technopole Brest Iroise, Rue Dumont dUrville, F-29280 Plouzane, France.
C2 UBO, FRANCE
   UBO, FRANCE
   UNIV LYON, FRANCE
   UNIV NORMANDIE, FRANCE
   CEREMA, FRANCE
   UBO, FRANCE
UM LGO
IF 3.364
TC 33
UR https://archimer.ifremer.fr/doc/00637/74933/88241.pdf
LA English
DT Article
DE ;UAV;SfM photogrammetry;Tilted camera;Cliff face erosion;Coastal monitoring;Normandy
AB UAVs are relevant for monitoring cliff faces. In this study, several flights are performed with various imaging angles (nadir, 20 degrees, 30 degrees and 40 degrees off-nadir) to assess the impact of the imaging angle on the 3D cliff face reconstruction. Occlusions issues arising with sub-vertical cliffs make nadir surveys nearly irrelevant. The results obtained with 20 degrees, 30 degrees and 40 degrees off-nadir imaging angles are satisfactory regarding texture restitution and accuracy with respectively 5.5 cm, 5.9 cm and 4.9 cm of error, higher tilting angles yielding better reconstructions on sub-vertical or overhanging parts of the cliff. This article also investigates other parameters affecting tiepoint detection on the cliff face, as the effective overlap, the UAV-cliff face distance and the cliff face illumination. Guidelines are provided for UAV survey parameterization, aiming at capturing the whole cliff face with a good trade-off between distance to the cliff, flight height and spatial resolution of the photographs. 
PY 2019
PD JUL
SO Measurement
SN 0263-2241
PU Elsevier Sci Ltd
VL 139
UT 000464638000002
BP 10
EP 20
DI 10.1016/j.measurement.2019.02.024
ID 74933
ER

EF