3
votes
0answers
17 views

Distortion in projected raster

I am having a frustrating problem with something that I think should be very simple. I have a number of DEMs from the National Elevation Dataset (NED), that come standard in the NAD83 coordinate ...
2
votes
1answer
61 views

Georeferencing a raster using GDAL and Python

I want to georeference a raster using python and GDAL. My current approach is to call gdal_translate and gdalwarp using os.system and an ugly list of ground control points. I'd really like a way to do ...
1
vote
1answer
18 views

Difference between source SRS and target SRS in Raster Warp function

Hello I am trying to change a raster layer projections from WGS84 to a custom Lambert layer using 'Raster' --> 'Projections' --> 'Warp' function. I have been asked for source SRS and get SRS. what is ...
2
votes
1answer
38 views

Error reading large virtual raster with rasterio: “Cannot invert degenerate transform”

I've created a virtual raster using gdalbuildvrt, which covers a large extent (England) at a high resolution. The data is fairly sparse, focused around the coastlines with no files covering inland ...
2
votes
1answer
134 views

How to find the projection of an image?

Instead of georeferencing the image and deforming it, I'm trying to find the projection used by the author of the image. I've got tens of these distribution maps to digitize. The idea is to avoid ...
3
votes
1answer
83 views

Projection mismatch when plotting precipitation with ggplot

I'm trying to plot accumulated precipitation in Brazil for a given period, see code below: Load packages library(raincpc) library(SDMTools) library(raster) library(ggplot2) library(rgdal) ...
0
votes
0answers
34 views

Euclidean Distance Function performed on unprojected data

I am looking to perform a simple multi-criteria analysis on a data set comprised of two criterion: occurence of wildfires and road accessibility. First, the project CRS was enabled with "on the fly" ...
4
votes
1answer
96 views

What's the correct way to reproject a population raster?

I'm working with a population raster that is in the WGS84 coordinate system, and I want to get it into a projected coordinate system (Albers Equal Area), using ArcGIS 10.1. According to the metadata, ...
0
votes
1answer
59 views

problem in scale of projected raster

I have a shapefile (my basin limit) and one raster file that I projected it to the shapefile coordinate system and set its cell size to 1000m(area=1Km2). my basin area is 5400 Km2 and it should ...
0
votes
0answers
39 views

Assign a particular projection for un-projected raster/vector files in a folder/sub-folders

We are having 1000's of raster images/vector (shp,tab,dxf) files in a folder/sub folders. Is it possible to check the projection of those and if it is an un-projected one? WGS 1984 has to be ...
0
votes
0answers
39 views

Raster projection problems

How would I go about specifying the following projection in Arc and QGIS? After defining this, how would I then go about changing the spatial reference to ESPG 27700? The following are the details of ...
0
votes
0answers
26 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
0
votes
0answers
35 views

I want to reproject data from 0-360 to -180 - 180 [duplicate]

I've been downloading data from NOAA in a CRS that goes from 0-360. The rest of my data is in -180 to 180. What's the easiest way to reproject or shift the data in QGIS? It took 30 seconds in ArcMap, ...
2
votes
1answer
49 views

does Pseudo Mercator Projection causes problem while clipping rasters

I tryed to clip a Raster file using an ESRI shapefile using gdalwarp command, but i always get an empty output file or a wrong clip with wrong location. this the command bellow: gdalwarp -dstnodata ...
0
votes
0answers
199 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
1
vote
2answers
421 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
0
votes
1answer
268 views

Equivalence of EPSG:3857 for MapInfo 9.5

I have a raster projected on EPSG:3857 with QGIS. I have image registration in Mapinfo but there is no projection for EPSG:3857. Do you know the projection that I need to use?
1
vote
3answers
479 views

Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
2
votes
1answer
135 views

Does ModelBuilder need to use variable to define projection and then re-project?

I am trying to build a Model in ModelBuilder to create two different process raster datasets: One set is to define a raster dataset to set a WGS 84 projection; and then the second set is to take ...
3
votes
2answers
196 views

Partial Map Pixel Projections

I have the following: A PNG or JPG of a random width and height, in pixels, that represents a partial map of the world (i.e. a rectangle of the United States). The four corners of this image are ...
1
vote
1answer
101 views

Raster Dataset projection problem

I have a problem connected with my Raster Dataset projection. Two of its bands cannot be shown in some scale - only under 1:1500, when I use 'Zoom to raster resolution' option. Histograms for all 3 ...
4
votes
1answer
2k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
2
votes
0answers
542 views

Projecting a Raster from WGS84 to planar Equal Area to Calculate Area: How to Select the Cell Size?

I have a broad question on how to calculate the 'correct' cell size for a raster when analyzing an area not at the equator. My goal is to project a land cover raster provided in GCS WGS84 to an equal ...
0
votes
1answer
198 views

Working with Interrupted Goode Homolosine data

I'm trying to use Global Land Cover Characterization data from the USGS: http://edc2.usgs.gov/glcc/fao/data_specifications.php It is in the Interrupted Goode Homolosine projection. As I am working ...
1
vote
1answer
119 views

GeoTIFF without projection?

I have encountered a GeoTIFF raster files with EPSG:4326 (WGS84), i.e. no projection defined! Is this normal? I would expect raster to be in Projected Coordinate System. Raster is a grid of pixels so ...
1
vote
2answers
833 views

How can I use GDAL to batch define a projection?

I have a fodler with 1500 ECW rasters, no spatial reference information defined. Can I use GDAL to batch define a projection for all 1500 in the folder?
0
votes
0answers
83 views

Why does a shapfile shift after transformation?

I have a shapefile created in the raster package (ER_14.3_2000_poly). > #read in a raster file > ER_14.3_2000<-raster('E:/Ecoregions Models/Outputs/ER_14.3/ER_14.3_ConsensusMap3.asc') > ...
0
votes
0answers
31 views

QGIS: Unable to project raster layers correctly on a Toshiba Tecra 64# Win7

I know how to project a raster, I can do it on other machines. On this particular machine the raster loads but are no where near the correct position as if the datum is on another planet.
2
votes
1answer
2k views

What are the units of the calculated area from a raster in decimal degree

I'm trying to calculate area for a raster file which contains 2 layers (0 for unsuitable habitat and 1 for suitable). It's been calculated successfully but I don't know what is the unit of the ...
0
votes
1answer
207 views

GMT raster (*.tiff + *.pgw) in epsg4326 shifts few kms (4326-900913-3857 problem?) [duplicate]

This seems to be an old problem with an already known solution (ie. "...stop using 900913 and start using 3857..."), but not sure whether this problem is about software versions, the raster itself or ...
1
vote
1answer
435 views

What are Bands, Dimensions, and Histograms in QGIS?

First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct? If so then bands play the role of color mixing and masking. Are there any other ...
1
vote
2answers
485 views

Why is Format of output data grayed out on Save As dialog for Rectify?

I started georeferencing and I could not save my new "rectify" file, I don't know if is because of the raster or I did something wrong. Then I find out that my control layer is not accurate, it ...
4
votes
1answer
1k views

How to re-project ease( Equal Area Scalable Earth) grid with a ~25 km cylindrical projection to WGS84 0.25 degree? [duplicate]

I have nc (NetCDF) files for global soil moisture. From the metadata, the projection is cylindrical and the resolution is 25 km (it is based on authalic sphere based on International 1924 ...
10
votes
2answers
748 views

How can I improve my Georeferencing results?

Background This is my second question related to georeferencing naked raster maps in order to re-visualize them on different coordinate systems and in conjunction with other data layers. The previous ...
3
votes
1answer
379 views

How to reproject a raster to Winkel Tripel projection?

I'm trying to project a raster map (in ASCII grid format) from longlat to the Winkel Tripel projection. But I'm running into errors, for instance gdalwarp won't accept the proj-string. $ gdalwarp ...
0
votes
1answer
197 views

Setting projection to a geotiff file when it's shown as Unknown

I have a geotiff file that has no CRS in the metadata but I know that the CRS of the raster is WGS 84 UTM 22 N. How can I modify the geotiff file to have the CRS WGS 84 UTM 22 N in the metadata. ...
6
votes
1answer
155 views

Is there a difference between projecting shapefiles then rasterizing & rasterizing shapefiles then projecting?

I currently have a project where I rasterize shapefiles into simple presence/absence (1 & 0) rasters and then add each one to a running total to create a total richness raster at the end. The ...
4
votes
3answers
1k views

Convert an arbitrary meta-data-free map image into QGIS project

My background: experienced programmer, amateur historian, complete beginner to GIS (so I'm using QGIS). I did learn to use the QGIS georeferencer tool though. The input: suppose I have an image like ...
2
votes
0answers
99 views

raster data expressed as percent

I downloaded NDVI greeness data from the USGS Integrated Vegetation Mapping Viewer. In the metadata it says that visual greenness values range from 0 to 100. My data is from the period ending 3/5/12 ...
2
votes
1answer
301 views

Reproject TM65 to OSGB in ArcGIS

I have a TIFF file in the TM65 (Transverse Mercator) projection, and want to convert it to the OSGB (British National Grid) projection. I'm trying to do this in ArcGIS using the Project Raster tool. ...
2
votes
2answers
1k views

Converting google map api coordinates into meters

How would I go about converting the results of my map bounding box into meters within javascript? For example, if I have the coordinates 51.52366625446907, -0.07467269897460938 decimal degrees, can I ...
5
votes
2answers
3k views

How do I use GDAL to convert from an arbitrary projection/datum into Equirectangular/WGS84?

I've been trying to use GDAL to convert from an arbitrary projection/datum into Equirectangular (aka Plate Caree, aka Equidistant Cylindrical, aka Geographic, aka Lat/Long) with WGS84 datum. All of ...