nsw_lidar
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nsw_lidar [2020/08/05 18:50] – bushwalking | nsw_lidar [2020/09/09 20:36] – [Resources] allchin09 | ||
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====== Resources ====== | ====== Resources ====== | ||
* [[https:// | * [[https:// | ||
- | * [[http:// | + | * [[http:// |
====== Topographic maps ====== | ====== Topographic maps ====== | ||
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The NSW DEM data is supplied in 2km squares. The squares need to be merged into a single DEM for further operations. | The NSW DEM data is supplied in 2km squares. The squares need to be merged into a single DEM for further operations. | ||
- | While this can be done in theory using a Virtual Raster, I have had poor performance with this (including recent version 3.12 Bucuresti). Any operation seems to result in screen redrawing, so moving around | + | Most of the eastern ranges, where a lot of bushwalking happens, are 2m DEMs. The coast is typically 1m, and the western slopes |
- | <insert function here> | + | ==== Virtual Raster ==== |
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+ | While merging can be done in theory using a Virtual Raster (Raster- | ||
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+ | That said, if you are just using the Virtual Raster for future steps, then the limitations from the screen redrawing may not be important. | ||
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+ | QGIS uses [[https:// | ||
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+ | ==== Merge Raster ==== | ||
I generally use the the Raster- > Miscellaneous -> Merge... function | I generally use the the Raster- > Miscellaneous -> Merge... function | ||
- | Note that while most of the eastern ranges, where a lot of bushwalking happens, are 2m DEMs, the coast is typically 1m, and the western slopes and plains are 5m (with major rivers 1m!). | ||
QGIS uses [[https:// | QGIS uses [[https:// | ||
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Run v.clean: Cleaning Tool = rmdangle, Threshold = 5,10 | Run v.clean: Cleaning Tool = rmdangle, Threshold = 5,10 | ||
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+ | ===== Dumping Ground / WIP ===== | ||
+ | ==== Resources ==== | ||
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+ | [[https:// | ||
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+ | [[https:// | ||
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+ | [[https:// | ||
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+ | [[http:// | ||
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+ | [[https:// | ||
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+ | [[https:// | ||
+ | ==== Method ==== | ||
+ | The below snip of Breakfast Creek makes use of TPI calculated from a LIDAR derived DEM. Only positive values for TPI as displayed, which indicate cliff-like features. It is then combined with contours and aerial imagery to convey the terrain of the area. | ||
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+ | {{: | ||
nsw_lidar.txt · Last modified: 2024/04/05 19:00 by bushwalking