Published September 1, 2017
| Version v1
Dataset
Open
Ngozumpa Glacier Gokyo ice cliffs photographic surface model
Creators
- 1. Univeristy of Innsbruck
- 2. Michegan Technical Univerisity
Description
Data files of a photographic surface model of three ice cliffs exposed on the surface of the Ngozumpa Glacier ( 27°57′N, 85°42′E), Nepal, near the village of Gokyo.
Details of how the data were produced:
- 1160 full resolution JPEG images were used to make the difgital surface model (DSM)
- Photos were taken using Nikon D5000 with 100mm Tamron macro lens on 4th April 2016
- 7 ground control points (GCPs) within the captured scene were used to scale and georeference the DSM
- GCPs were measured using a Trimble XH6000 with Tornado antenna as rover and a Trimble Geo7X with Zephyr antenna as a local base station
- Agisoft Photoscan (v1.26) was used to make the DSM using a SfM-MVS workflow
- Point pairs appearing in only one image pair and havoing a reprojection error grreater than 0.5 pixels were removed
- Model optimization was done using default parameters of f, b1, b2, cx, cy, k1-4, p1 and p2 and, as the lens distortion plot showed no extreme skewing or distortion, these optimization settings were accepted.
- The dense point cloud was generated using the ‘High’ quality setting with ‘Aggressive’ point filtering.
- The dense point cloud was then used directly to generate the DSM and orthomosaic at resolutions of 0.046 and 0.023 m respectively.
Description of files:
- GokyoIceCliffs_POINTCLOUD.txt: dense point cloud including the whole scene covered by the photographs. Format: x,y,z, text file, WGS 84 / UTM zone 45N.
- GokyoIceCliffs_DSM_0.04.tif: 0.046 m resolution digital terrain model derived from the dense point cloud covering the area of interest including the 3 sampled ice cliffs. Format: TIFF WGS 84 / UTM zone 45N.
- GokyoIceCliffs_ORTHO_0.04.tif: 0.023 m resolution orthophoto covering the area of interest including the 3 sampled ice cliffs. Format: TIFF WGS 84 / UTM zone 45N.