Tagged Questions

In a planar coordinate system, three coordinates that locate a point by its distance from an origin (0,0,0) where three orthogonal axes cross. Usually, the x-coordinate is measured along the east–west axis, the y-coordinate is measured along the north–south axis, and the z-coordinate measures height ...

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3
votes
2answers
54 views

How to create a raster tiff (dem / heightmap) from a mesh of xyz points?

I have to create a terrain heightmap(raster tif preferably) from mesh of xyz ungridded points(in geographical coordinates), I tried taking min and max of bbox of mesh and making width & height by ...
3
votes
3answers
56 views

Which raster resolution (DEM) can I get out of lidar data with variable grid width?

I have ASCII files in *.xyz format and want to generate a DEM out of it. According to the information about the data the *.xyz files are containing variable grid widths - from 1 meter to 4 meter. ...
1
vote
2answers
47 views

Equations to convert from global cartesian coordinates to geographic coordinates

First, I needed to convert geographic coordinates (like those received from GPS) to global cartesian coordinates. I found an earlier question (How do I calculate a xyz-position of a gps-position ...
2
votes
1answer
64 views

How to convert different lidar data formats to raster DTM and measure its geographic position accuracy?

I'm trying to generate a DTM from lidar data and I'm new in the this field. I have different kind of files which describe the same area (different versions): *.dtm *.xyz *.xyz with variable grid ...
2
votes
0answers
38 views

Changing grid orientation of a raster

I'm trying to load some XYZ data into a program called OpendTect. However, the orientation of the existing data is different from the grid orientation of the XYZ file. this makes it imposible to load ...
3
votes
1answer
119 views

How to transform XYZ Raster from WGS84 to UTM ED50 Zone 34

i'm trying to convert an XYZ file from WGS84 (lat/long) to UTM ED50 zone 34. Qgis can load the file as a raster, but i cant see a way of changing the coordinate system or exporting the results as an ...
2
votes
0answers
62 views

How can I store height info from GPS in QGIS?

I want to use QGIS as a tool for collecting GPS-Data in the field. One use case would be simple surevy tasks where I want to store the three dimensional position of points. QGIS is working fine on the ...
1
vote
2answers
109 views

How to view locally generated XYZ map tiles?

Is there an easy way to test (view on a map) my locally generated XYZ map tiles? I've used OpenLayers and Leaflet to display non-local XYZ map tiles, and I could conceivably push these tiles to a ...
0
votes
0answers
20 views

Derive Z-coordinate

I use an GNSS receiver with RTK-support. In my field computer I use arcpad 10, when I make a shape-file with points I would like the attributes to be x,y,z coordinates or some other way to get x,y,z ...
0
votes
1answer
481 views

QGIS 2.2: GDAL Grid (Interpolation) Error

As much as i understand Raster -> Analysis -> Raster (Interpolation) can provide me with a terrain file out of a shape file with a Z coordinate. I select the input and output file and a Z field. It ...
2
votes
1answer
78 views

Averaging XY points locations if in close proximity automatically over a large dataset in R

I have a point dataset (XYZ values) containing a few million points covering a 5km x 5km extent representing maxima locations. However there a great deal of these points which exist in 0.5m of others. ...
0
votes
2answers
132 views

Grass GIS 6.4.3, How to create a .PTS file

I'm trying to export a raster map in order to use it in the Flo-2d program. This program needs a .pts DTM file, do you know how I can create it? Alternatively, I can use a XYZ file looking like this ...
2
votes
1answer
1k views

How do you import simple xyz in QGIS

I have found out how to get tab-delimited X,Y data into a layer but the Z field value is not given as an option on import? I tried to edit the attributes to add and define a new field but it keeps ...
0
votes
1answer
118 views

Calculate attribute height of point data

I have an x (easting), y (northing) and z (height) values associated with my point shapefile. I would like to calculate the z values from the DTM I have - how do I do this in QGIS? I am fairly new ...
0
votes
0answers
190 views

Why is Field Calculator Returning NULL for $x and $y?

I am trying to include XY coordinates in the attribute tables of several of my vector files. I have tried two methods; first I used $x and $y in the field calculator (which I've used before and ...
1
vote
1answer
488 views

Create a 3D surface from xyz csv using GRASS

Apologies if this is a repeat question guys. I am trying to create a 3D bathymetry surface from xyz data. There is approximately 300,000 points with lat, long and z (depth data). The data is sonar ...
1
vote
0answers
175 views

Map with custom tiles having uncommon EPSG

I've produced with mapnik my own tiles with EPSG:31256 on a shapefile. I've structured the tiles in a OSM-like tree: zoom/x/y.png, with zoom from 0 to 2 and, x y starting from 1: tiles ├── 0 │ ...
1
vote
2answers
3k views

importing XYZ to arcmap

My colleague has several hundred xyz files (*.xyz) and wants to make a DEM to use it in ArcMap. Files have three columns witohut first lane (variable names). I suggested her: to add first line with ...
0
votes
2answers
3k views

convert geotiff to simple xyz elevation file?

I have looked everywhere and can not find a tool to convert a geotiff file to a simple ascii elevation file... did I miss something? thanks for any pointers!
1
vote
0answers
245 views

Print XYZ layer with MapFish Print plugin

I have a XYZ layer(i hope i call it right) in GeoExt/gxp application: ,{source: "ol",group: "background",fixed: true,type: "OpenLayers.Layer.XYZ",args: ...
-1
votes
1answer
354 views

Converting Easting, Northing, and Elevation to Station and Elevation

How can I convert x,y,z (easting, northing and elevation) data into station and elevation? I am trying to input the data into HEC-RAS, which only takes station and elevation.
1
vote
2answers
760 views

What software is available on OSX for working with DEMs?

I have several adjacent DEM files and would like to combine them into a mosaic and then export to DEM and TXT. I know a Windows solution is to use MICRODEM but before installing Windows 7 I would like ...
4
votes
2answers
284 views

Huge x,y,z dataset into oracle, possible?

I have 200 .xyz files containing 1500000 points each. Is this possible to import this dataset to oracle? It makes a total of 300.000.000 points!!! Background is I want to improve a FME script that ...
5
votes
3answers
602 views

Finding outliers with wrong Z values in LIDAR data

I have more than 2000 XYZ (only ground points) .txt files and I have to do Quality Control (QC). Let's say I have file, which I converted to multipoint (or even singlepart feature). I have mean Z ...
5
votes
2answers
385 views

Symbolizing xyz data

I have hydrographic data in the form of an xyz file. I would like to display it in ArcMap. I need to symbolize the points based on their depth, shallow points one colour and deep points another. With ...
6
votes
3answers
2k views

What is XYZ format in QGIS?

Basic question, but I have been asked to export data to an XYZ format. Is this the same as CSV files. I am using QGIS 1.8.0. So i am presuming i select the data I want to export, right click its ...