Cite this dataset as
Ashworth, P., Nicholas, A. , Parsons, D., Sambrook Smith, G. (2019). Digital Surface Models for the South Saskatchewan River, Canada. NERC Environmental Information Data Centre. (Dataset). https://doi.org/10.5285/13695138-227f-4d85-9049-0a9cba9e1867
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This dataset is available under the terms of the Open Government Licence
Digital Surface Models for the South Saskatchewan River, Canada
Format
txt
Spatial information
- Study area
-
- Spatial representation type
- Tabular (text)
- Spatial reference system
- WGS 84 / UTM zone 13N
Temporal information
- Temporal extent
-
2015-05-13 to 2017-06-12
Provenance & quality
The DSM was constructed from photogrammetric quality aerial plane images with a 0.06m ground resolution that were captured at a height of c. 1500 m from a fixed-wing aeroplane with an UltraCamXp sensor. The DSM was constructed from the images using a three stage process:
(1) An orthomosaic was generated from the aerial photography (using up to 160 images) by automated image matching using the SfM program Pix4D (https://pix4d.com/) with the 'large frame' supplementary software package. Bundle adjustment was undertaken using Pix4D’s key point matching system optimised for aerial nadir imagery. Camera properties were specified using calibration certificates and were not allowed to vary during the calculation. A point cloud was then derived following the bundle adjustment.
(2) The point cloud was checked for residual tilt using a network of Ground Control Points with coordinates that were determined by RTK differential GPS survey. The corrected point cloud density was reduced to a resolution of 0.5 m and the resulting dataset was filtered in MATLAB using a Chauvenet-type criterion. This procedure was implemented to derive the DSM in dry (non-submerged) areas of the river.
(3) In wet (submerged) areas, bed elevations were derived using a depth-brightness model as follows. First, water surface elevations at the interface between wet and dry areas of the river bed were extracted from the corrected point cloud and interpolated to generate a water surface elevation field for the submerged bed areas. Second, water depth measurements made at the time of image acquisition were located on the orthomosaic of the river, and pixel brightness values were extracted at these locations. A log-linear regression between water depth and pixel brightness was then derived, and this relationship was used to model water depth for all sub-merged bed areas. Bed elevations in these areas were determined by subtracting the predicted depth from the water surface elevation. The final DSM was derived by combining elevation values for the dry and wet bed areas.
Related
This dataset is included in the following collections
Modelling how sediment suspension controls the morphology and evolution of sand-bed rivers
Citations
Correspondence/contact details
Authors
Other contacts
- Custodian
-
NERC EDS Environmental Information Data Centreinfo@eidc.ac.uk
- Publisher
-
NERC Environmental Information Data Centreinfo@eidc.ac.uk
Additional metadata
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By accessing or using this dataset, you agree to the terms of the relevant licence agreement(s). You will ensure that this dataset is cited in any publication that describes research in which the data have been used.
This dataset is available under the terms of the Open Government Licence
CITE AS: Ashworth, P.; Nicholas, A. ; Parsons, D.; Sambrook Smith, G. (2019). Digital Surface Models for the South Saskatchewan River, Canada. NERC Environmental Information Data Centre. https://doi.org/10.5285/13695138-227f-4d85-9049-0a9cba9e1867
© Natural Environment Research Council