Linked Questions

1
vote
1answer
95 views

Generating DEM Generation in LPS?

I have a Cartosat 2.5 m Imagery and Block files along with DSM Data. I wanted to generate DEM using Leica Photogrammetry Suite Software. Does anyone know the steps of generating same? I have to edit ...
12
votes
4answers
6k views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
2
votes
2answers
6k views

Interpreting .ASC/LiDAR Data?

I'm a complete novice to the world of GIS. I'm involved with a project which requires LIDAR data to be imported into CAD software. When I go to the geostore, which contains LIDAR survey data ...
1
vote
1answer
877 views

Generating Canopy Height Model (CHM) with Quick Terrain Modeler?

I currently looking forward to process LiDAR point clouds (forest data) using Quick Terrain Modeler (QTM), but is it possible to create Canopy Height Model directly using the software?
6
votes
1answer
1k views

Calculating shadow of trees with DEM in QGIS?

I have a DEM with a good precision (0,5 x 0,5 m/pix LiDAR) and I´m looking for the way to obtain a raster (or shapefile) with the shadow of the trees located in that place for a whole day (ideally ...
2
votes
2answers
318 views

Getting a flat surface from DSM for height calculation?

I have a DSM done trough photogrammetry with the software Agisoft Photoscan of a forestry experiment and I need to accomplish an analysis of the mean height from it. My problem is that the profile has ...
2
votes
1answer
2k views

Why ground model from point cloud in Global Mapper is inaccurate?

I have a LAS file that I assumed was based on LiDAR, but it is actually based on ADS (airborne digital sensor) imagery, according to the body that captured the data. I load the file in to Global ...
7
votes
5answers
19k views

Converting LiDAR data to raster (DEM/DSM) for ArcGIS input?

I was wondering if there is an option to convert LiDAR data (.las) to a raster/grid (DEM/DSM) format that ArcGIS 10.0 can read?
12
votes
4answers
5k views

Comparing two Digital Elevation Models (DEMs) from LAS files?

I have two LiDAR files (.las), one is original let's say with X points. And the other is copy of the first .las file but with Y points, where Y is less than X. Now, I want to compare the Digital ...
9
votes
2answers
1k views

Retrieving heights of buildings using remotely sensed data (except lidar)

How can I get the height values of buildings from a certain sector a city without going into the field to collect data? Is there anyway to do via satellite imagery, SRTM, ASTER GDEM or any DEM for ...
1
vote
1answer
71 views

Checking Vegetation height accuracy in urban areas

I have digitized vegetation as polygons covering the canopy of trees in urban areas. Are there any suggestions to check the accuracy of height. I have been manually validating with visual checks, ...
4
votes
1answer
3k views

DTM extraction of tree heights

I need to classify tree heights in a DSM of a slope-y terrain. It´s not a forest but several individual / detached trees. In a plane terrain it won´t be an issue but in that uneven terrain I need ...
0
votes
1answer
212 views

how to create a point shapefile with azimuth and elevation?

I have downloaded a GPS almanac file which gives azimuth and elevation for each GPS satellite at a particular latitude and longitude. I want to create a point file with azimuth and elevation angle ...
6
votes
3answers
1k views

Is there a DTM available for free somewhere?

To go a little bit further than the semantic question regarding DEM/DTM/DSM, I'd like to know if there is a free (of charges and use) DTM datasets? And what about resolution? As far as I know,only ...
1
vote
1answer
384 views

Difference in the elevations for the same building on two DSMs saved in *.asc and *.laz formats

The following question concern the same type of data as the one I've asked in Differences in the longitude and latitude between a LiDAR DSM and an optical image. Basically, I've downloaded a tile of ...

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