Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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1answer
97 views

Numbers containing e in ArcGIS?

In ArcGIS when I try to calculate some raster values or statistics, sometimes I get values that contain e, for example: 1.4e6. What does e mean, and how is it interpreted in ArcGIS?
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2answers
428 views

How to effectively merge SRTM 1 arc data?

We have around 1800 1 arc-second SRTM tiles (Geotiff). How to effectively merge all the tiles into one single file ? We are thinking about splitting 100 files per folder and merge them together using ...
2
votes
1answer
249 views

Create Raster Surface from Points and Equations in ArcGIS

I want to use point data to create a raster surface which distributes the values over space, as defined by an equation, and NOT by interpolating. I have an equation to describe how the characteristic ...
2
votes
2answers
221 views

How calculate pixel by pixel the mode (statistic) of multiple rasters (geotiff)?

I have 12 land cover maps, and I would like to calculate the mode to each pixel of the 12 maps (they have the same resolution and dimension). I mean, the final map would be the mode for each pixel of ...
6
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1answer
211 views

How to perform a non-linear regression pixel by pixel?

Using nlsLM from Package ‘minpack.lm’ is straightforward for a simple example like this: MODEL:y=(exp(a*x+b*z+c)+d)^f x=c(0.5,0.3,0.2,0.4) z=c(0.1,0.6,1,0.9) y=c(0.2,0.3,0.9,0.9) ...
0
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0answers
38 views

How to avoid a problem of one pixel when doing non-linear regression?

I am ruining a non-linear regression using nlsLM from package:minpack.lm for multiple rasters (pixel by pixel). My initial values may be appropriate for some pixels but not for others.When I run the ...
2
votes
1answer
42 views

How do I count the number of cells which can see each cell in QGIS

For each cell in a DEM I'd like to count the number of cells which can see it (i.e. direct line of sight) - Can anyone explain how to do this in QGIS? Thanks,
0
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0answers
68 views

Creating a time series from multiple rasters in ArcGIS

I have 10 rasters (10 yearly averages of data) that I've uploaded into GIS. I would like to do two things: Create a time-series of the values of that raster at one specific point within it. Create a ...
6
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1answer
1k views

Python equivalent of gdalbuildvrt

Is there a way to perform the same task as the gdalbuildvrt utility using GDAL Python bindings? So far I have not found any way to do this other than creating a vrt of a single dataset and manually ...
1
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1answer
90 views

QGIS Raster Calculator, joining two raster

In QGIS raster calculator I do: Plus (+) And I get: The red circle in the middle is like cut in the result, QGIS it's not adding every pixel on each raster, it makes a kind of ...
2
votes
1answer
90 views

Make a ground mask raster with the Greater Than tool

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
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1answer
200 views

Cost Distance interpretation in ArcGIS 10.2

I am using the Cost Distance tool in ArcMap 10.2 to find the how far it is to walk to the closest area of green space along the road network in a town. I have a input raster of the location of the ...
24
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6answers
1k views

How to buffer raster pixels by their values?

The pixels to the left represent tree locations and their associated crown radii (i.e. pixel values ranging from 2 - 5). I would like to buffer these raster pixels by their crown radius value. The ...
0
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0answers
45 views

crop shp file leads to different results for same extent

I cropped a shapefile to a smaller extent (my AOI - area of interest) - to work with a reduced working directory. During my workflow I rasterize the shapefile. Here is my problem: I saved both of my ...
1
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1answer
214 views

Scanned Transparent Map Overlay

We have a flat file of 50 Geology maps that have a transparent overlay with faults and drill holes. I have them scanned and georeferenced as TIF images and they will be used in ArcGIS 10.0, 10.1 and ...
3
votes
1answer
259 views

Converting worldclim data to 30m resolution

I know that resampling from coarse resolution to fine resolution is bad. Effectively you are making up data. However, if the study area is small are there any other options? Worldclim comes at around ...
2
votes
0answers
91 views

QGIS 2.8 Raster Layers Moved [duplicate]

I recently downloaded QGIS 2.8 and opened an existing project in it to check how it handled it and make any changes required. This project includes several raster heatmap layers. My problem is that ...
1
vote
1answer
378 views

How to convert SQL Server Rasters to ASCII Grid?

I have 25km by 25km squares of the world in a relational database. Each square has coordinates for the top left and lower right corner as latitudes and longitudes. Each square also has an index ilat ...
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1answer
160 views

Georeference multiple raster layers of same area at once or identically

I have many raster layers that I need to georeference to my existing vector layers. Data types vary between 8 bit unsigned, 32 bit float, and bit 64 float. All have the exact same extent, cell size, ...
0
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0answers
333 views

Raster to polygon with RGB composite using Arcgis

I am trying to convert an RGB composite to a shapefile to use with. The raster to polygon function returns with three shapefiles with "grid_code" of the value of each of these three channels. I am ...
1
vote
1answer
249 views

How to make a density map from polygons/rasters (ArcGIS)

I would like to make a density map of grasslands. I have a vector layer of habitat classifications, I would like to a density map of grasslands within a specified radius. My thoughts are to: ...
2
votes
1answer
1k views

Orux Maps raster display

Does anyone know what format of raster images works with Orux Maps? I tried to export maps acc to Orux Maps specs from ArcGIS 10.1 in every possible format (Geotiff, GRID, jpeg2000...), loaded with a ...
27
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3answers
3k views

How to represent trend over time?

I have a time series of rasters where the cells of each raster represents some value at a certain time. I'd like to generate a map that highlights the magnitude of positive or negative trends in this ...
0
votes
1answer
53 views

Reduce raster resolution based on cell ratio

I have 2m impervious/non-impervious data. I would like to reduce the resolution to 30m and have the cell value for the 30m data be determined by the ratio or proportion of impervious / non-impervious ...
3
votes
2answers
1k views

How to generate wind direction raster using its U and V components in arcgis?

I have two raster layers representing the U and V components of a vector wind. I could generate the magnitude raster by applying (u*u+v*v) in Map Algebra in ArcGIS. Now I need to generate the ...
2
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0answers
223 views

ImportError: No module named gdal qgis2.8.1

i am using QGIS 2.8.1 (32 bit) in windows 7). I imported two DEMs and trying to merge (QGIS>Raster>Miscellaneous>Merge)them. Unfortunately it gives me import error as below. Traceback (most recent ...
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1answer
81 views

Add information from polygon to raster in R

I would like to add information from a spatial polygon to a new raster. r <- raster(nrow=10, ncol=10) r[] <- runif(ncell(r)) * 10 xym = matrix(c(0,0,0,45,45,45,45,0),4,2,byrow=T) ## create ...
1
vote
1answer
105 views

Raster display issue in ArcMap?

A client of ours is having trouble with some raster tiles in ArcMap. They gave me a sample, and I was able to get it looking right with the following workflow: All you have to do is go into each of ...
1
vote
1answer
46 views

QGIS change raster tiles properties at once

I have a set of several raster tiles and I need to change the properties of each one, by setting up a transparency for instance. I have found no other solution but changing properties of each one at a ...
0
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0answers
89 views

Problem with conversion from raster to polyline (not a single curve)

I have raster file and I need to convert it to line. I used GIS tools Convert Raster to Polyline but the line segment is not straight and it is divided into no of segments, isn't it possible to get ...
2
votes
2answers
160 views

GDAL - Warping raster to new domain/resolution/projection causes data loss

I am attempting to warp a GTiff from a lat/lon projection to a higher (~2x) resolution Polar Stereographic grid. In the output GTiff any cells north of 64 deg lat become NaN instead of their actual ...
2
votes
1answer
108 views

Georeferencing uneven/irregularly gridded rasters

I'm trying to take a set of NetCDFs and turn them into georeferenced datasets using GDAL. However, the only Geospatial data is a set of 2-D lat/lon arrays. The projection type is not lat/lon. THe ...
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1answer
220 views

Use raster memory layer from QGIS processing result

I want to apply subsequent QGIS raster processing algorithms in a python script. I want to use memory layers for intermediate calculation results since I am only interested in the end result. As ...
1
vote
1answer
34 views

Performing raster calculation in ArcGIS Desktop?

I have a raster layer with values between 0 and 10. My second layer consists of 0's and 1's. What I need is my first layer, but with 0's or NoData values where my second layer has 1's?
0
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1answer
72 views

QGIS extend raster layers extension

I want to extend a raster layer to another layer's extension (my input raster layer is smaller). The new raster cells should have 0 value. Is this possible in QGIS?
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76 views

Apart from “in-memory” space and physical geodatabase, is there any other method to process raster data?

Using the centroid of the building footprints (tagged residential), I want a count of hydrants within 135m, and a count of hydrants within 270m of every residential footprint. This would be based on a ...
1
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1answer
90 views

Raster layer - changing values in raster cells

I have a lot of cells in a raster layer (GeoTIFF) with a -9999 value in it. I would like to update that values to 0. I mean, in vectorial layers would be something like: CASE WHEN band1=-9999 THEN 0 ...
0
votes
1answer
129 views

Converting raster presented in KML to polygon using ArcGIS Desktop?

I have spent quite a lot of time Googling which brought me many places including this site, but I haven't found the resolution. I have a KML that presents a PNG. Radio Mobile generated the files and ...
2
votes
1answer
100 views

Is there a better way to convert Raster to Point data? Don't need one point for every cell

I need to convert raster data to point data so I can use the points for interpolation via kriging. My problem is that my resolution is 5 ft and I'm working on a whole city. The data I am converting ...
2
votes
1answer
411 views

Convert a KML ImageOverlay to World Files with GDAL

I have many raster outputs from an Open Source radio transmission topographic path tool called SPLAT, georeferenced in KML image overlay format. I have figured out an easy way to use tools to ...
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0answers
31 views

How do you symbolise a 32-bit raster in ArcObjects?

For rasters that are ABOVE 16-bit - you cannot apply a colormap - so what is happening when you symbolise in ArcMap a 32 bit raster, it's certainly possible. I'm trying to emulate this funcitonality ...
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0answers
29 views

QGIS Rasters - Filling no data cells [duplicate]

When making a sum between two raster layers, for every cell, if one of the two cells have no data in that cell, the opeartion is not done in that cell, example: In QGIS raster calculator I do: ...
4
votes
2answers
623 views

What is the source of horizontal and vertical striping in USGS DEMs?

When processing 30m and 10m DEM data downloaded through the National Map Viewer from the National Elevation Dataset, we noticed horizontal and vertical striping not only in the produced results, but ...
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vote
0answers
118 views

Metric maps vs topological maps for path finding and UI rendering of indoor floor layouts

I'm building a software to map indoor floor plans of large facilities (like malls). I read through some of the questions on this forum, but my constraints are a little different than the ones ...
0
votes
1answer
675 views

Import GeoTIFF into MapInfo - why “control points”, and how to batch-create TAB files?

OK, so I am largely hostile to commercial software with 'proprietary' formats, but a colleague only knows MapInfo. I have a bunch of GeoTIFFs (produced by gdal-merge of JPG/JGW-filepair hi-res aerial ...
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0answers
139 views

How to import Esri Raster to IDRISI with NoData value?

I made some point features in ArcGIS Desktop to build training samples to import to IDRISI. I had 7 classes and convert the feature to raster to build the signature in IDRISI. When I import the data ...
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0answers
29 views

Aligning to DEM after TIFF conversion to GRID?

I can convert a TIFF (NASS Cropscape) by using Create Raster in my .gdb or Export to other Format. However, all efforts to align the extent to an existing DEM have escaped me! I have tried Snap ...
2
votes
2answers
204 views

How to get cell value along Flow Direction

I have: a flow direction raster where I took off (assigned NoData value) the cells that overlayed the river network (from flow accumulation). a perfectly overlapping raster where I asigned a ...
2
votes
0answers
97 views

Adjusting heights within a DEM raster for visualisation

Problem I have a bathymetry DEM which I want to display in 3D (ArcScene or Fledermaus). The data set is one single raster but looks like it is a mosaic of several smaller datasets. The problem is ...
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vote
1answer
246 views

How to draw contour line between certain elevation range?

I have a raster and I want to draw contour lines just between certain elevation range. For example I want to draw contour lines between elevation 700 (m) and 1000 (m) with the interval of 10. So there ...