5,508 reputation
514
bio website surfaces.co.il
location Israel
age
visits member for 3 years, 2 months
seen 2 days ago

I work at the Arava Drainage Authority and Regional Council in southern Israel, doing hydrological analysis and general mapping. Involved with open source software since 1996, and FOSS GIS since 2006. I've also organized a few short GIS training seminars based on open source software.


2d
comment How to merge two rasters when are on the same place
If your first raster is a shaded relief, then it does NOT contain elevation values, rather colors to show a kind of 3D picture. What you need is the original raster of height values that was used to create this "picture of relief"
2d
comment Receiving NULL values from Point Sampling Tool in QGIS
OK, you would see identical CRS information in the Metadata since you had already set that using "Set Layer CRS". I added a second option to accomplish the task with GRASS, if you choose. Edited in the above answer.
2d
revised Receiving NULL values from Point Sampling Tool in QGIS
added 814 characters in body
May
21
comment Create blank table from unix shell
BTW, shp2pgsql should not need empty tables created in advance. It just outputs the full SQL commands for creating and populating spatial tables, to be piped into pgsql.
May
21
revised Receiving NULL values from Point Sampling Tool in QGIS
added 2 characters in body
May
21
answered Receiving NULL values from Point Sampling Tool in QGIS
May
17
answered Loop through table, look for word in text field, set boolean true if word exists
May
16
answered How to create custom color ramp using “r.colors” GRASS GIS function?
May
15
comment DEM with bathymetric contour lines in GRASS
You region settings are giving you rasters of over 3 billion cells. Are you sure you need such high resolution? If I'm not mistaken, each raster layer will take 25GB of disk space.
May
12
answered Projection change in QGIS after import & export in Grass
May
8
answered DEM with bathymetric contour lines in GRASS
May
8
comment distance() function in field calculator gives unexpected results
Your intuition was right. You cannot calculate distances between features in different coordinate systems.
May
8
comment Looping inside r.mapcalc in GRASS GIS
I guess I didn't quite understand your question. If you want to do any kind of weighted average of the Landcover classifications then you'll loose the classifications. Do you already have in mind a set of new classifications such as "sparse vegetation", "dense vegetation" with the values that you expect, as percents of the original classes?
May
7
comment Looping inside r.mapcalc in GRASS GIS
Don't you want to be using r.resample or r.neighbors with method=mode?
May
3
answered Migrating from ArcGIS to gdal
May
1
comment Move Landsat 7 Image in Grass 7
I must say, I have never heard of Landsat image bands not aligning. It might be worthwhile to download the same Path/Row for some other date, and compare.
Apr
29
comment Move Landsat 7 Image in Grass 7
Are the images the originals, in the original UTM projection? Are they the same path and row?
Apr
28
comment Calculate area intersected areas, problem
And when you reproject with ArcGIS what do you get? Are the new shapefiles then in the Albers Equal Area projection? I you have the original data, and you can share it, we could have a look...
Apr
26
comment Calculate area intersected areas, problem
What do you by "Reprojecting doesn't work". What do you get if you do "Save As..." and choose the Albers Equal Area projection of the Catchments layer? You should NOT use the "Define current project". That often confuses folks.
Apr
25
answered Calculate area intersected areas, problem