Tagged Questions

The estimation of values at unsampled points based on known values of surrounding points.

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2
votes
3answers
279 views

How can I generate and publish raster images?

I have several hundred groups of data points (in lat/lng format). I want to generate heat maps for each group using kriging or similar interpolations and then display the generated raster images on a ...
0
votes
4answers
53 views

How to clip rasterdata for later processing?

My need to dwell with geographical tools is only temporary, thus I am not well versed and my question is difficult to pinpoint exactly. But here it goes: -I have about 5-10 sites, for which I need ...
0
votes
0answers
21 views

How to spatialy interpolate forest tree height , basal area data for certain species

I have ecological sample data collected from 5 locations. I have point shapefile with 5 points where samples were collected. I have joined tabular data with the point layer by duplicating the points ...
1
vote
1answer
40 views

IDW: Default Maximum Distance and Coincident Points

The ArcGIS Help file says the Default Maximum Distance, when using the Variable Search Radius in IDW, is the extent's diagonal, however, no value is automatically filled in the corresponding box after ...
1
vote
0answers
29 views

Generating “weighted convex hull”

sadly I don't have any keyword that reflects what I'm looking for: I have a vector layer consisting of points, which have an integer attribute ("signal quality" here), that I want to plot as a convex ...
1
vote
2answers
40 views

contour lines from point shape attribute

I have a point shape file and one of the attribute refers to the altitude. Is is possible to obtain a contour lines shape file in GRASS?
2
votes
0answers
77 views

How to interpolate GPS data correctly?

I'm working on a project that involves using linear interpolation to fit lines to lat/lng points. I'm pretty new at scientific programming related stuff, and I was wondering if people could steer me ...
2
votes
1answer
119 views

Postgis 1.4 - Obtain closest point of point over polylines layer (without st_ClosestPoint)

I´ve got a polylines layer (pipes) and a points layer (valves) and In Postgis 1.4 I would like to obtain the closest points but exactly on the closest polyline. In other words, i need to locate each ...
0
votes
0answers
20 views

Limiting the maximum and minimum values of an interpolation surface tool (ArcGIS, Spline)

I've been using the spatial analyst spline tool in ArcGIS 10.1 and was wandering whether it is possible to limit the maximum and minimum values to those of the z-attribute. Currently the spline will ...
5
votes
1answer
130 views

ModelBuilder: How to extract data by date, export to separate tables and interpolate tables to rasters

I've been using ArcGIS for a couple years, but when it comes to model builder I've only worked with very simple models. I'm hoping someone that is much smarter than myself can help me in building a ...
1
vote
0answers
550 views

two results of IDW in ArcMAP are different

i added the following points to ArcMAP using "Add XY Data". x,y,z 7,39,117 27,17,122 27,61,123 46,36,136 52,14,138 55,46,141 56,56,137 65,24,144 65,36,145 Changed raster output size in "options" ...
6
votes
2answers
92 views

IDW spatial interpolation: appropriate projection?

I am wondering if anyone can clarify whether point data should be projected to an equidistant projection when using ArcGIS IDW spatial interpolation? I am working on a dataset from Western North ...
0
votes
0answers
38 views

project geotiff to NSIDC Sea Ice Polar Stereographic North (EPSG:3411) with gdalwarp

I a trying to project a signed byte .tiff file (sea ice concentration data) from a uniform unprojected grid (latitudes: -89.875° to 89.875° by 0.25°, longitudes:-179.875° to 179.875° by 0.25°) to ...
1
vote
0answers
49 views

Plotting time-series data in ArcGIS

I'm attempting to produce interpolated plots of water quality time-series data from ArcSDE. This is the data format: OID WELL_ID WELL_NAME SAMPLE_ID SAMPLE_DAT PARAM RESULT ...
11
votes
3answers
235 views

PostGIS interpolation / triangulation options

I'm looking for an open source workflow to automate DEM construction. We have a series of sites that fall within a LIDAR dataset. We want to create site specific DEM's for each site, and we're ...
1
vote
0answers
64 views

“topo to raster” tool

is there any analogue of "topo to raster" tool (ArcGIS) in QGIS? I need to creates surfaces from shp for some cases from points and for some from lines and this instrument is very convenient.
2
votes
0answers
136 views

z-Coordinate and interpolation plugin in QGis

I've a csv file that includes weather stations locations (x,y,z) and precipitation values. I loaded the file by using add delimited text and then converted it into a point shapefile WS84. By using the ...
4
votes
1answer
153 views

How to interpolate polyline or line from points?

We have a lot of points, but with no timestamps to create ways. For now, I've created a sample of the way the points traverse. It's in here, this way can be compared with a Google one. I haven't ...
3
votes
0answers
88 views

Can ArcGIS handle missing values to create a contour map?

I am trying to create a contour map for a waterbody. It turns out that in several locations there is no data. I just don't want to use the missing values as zero in ArcGIS because it would create ...
3
votes
1answer
108 views

How can I select which interpolation technique will be used in a gdal command? (gdal_fillnodata.py)

I work on Landsat 7 slc-off images and I would like to use the gdal_fillnodata.py command to fill-in the missing pixels. The problem that I have is that the gdal_fillnodata.py uses the "inverse ...
1
vote
1answer
60 views

Tranform Lat/Long NASA points into raster

I have this irradiation file and I would like it to upload it in ArcMap in order to overlay it with other layers to do clips, intersections, etc? ...
4
votes
4answers
255 views

TIN interpolation crash in Qgis

I have problems using the function TIN(linear) interpolation in Qgis. The program crashes when larger areas is interpolated. Map properties: vector map, Geometry typ = Point, features in this ...
10
votes
1answer
390 views

Minimum number of samples for kriging interpolation

I get some data with number of specimens with a request to interpolate it using kriging method. After some investigation it appeared that kriging results (performed in ArcGIS Geostatistical Analyst ...
3
votes
1answer
197 views

Interpolating Maps - Statistical Learning Techniques vs Spatial Statistics Techniques

I have recently begun experimenting with the inteprolation of variales over a whole country. I have good sized training set where I have several dependant variables (continuous and categorical) ...
7
votes
4answers
1k views

How to interpolate temperature correctly?

I tried to interpolate the mean avyerage annual temperature to produce a "realistic" surface.In qgis I used Raster-Interpolation-Interpolation. Both methods TIN and IDW did not deliver a "realistic" ...
11
votes
6answers
1k views

Looking for interpolation tool to produce river bathymetry (topography) from sections

As per the title, I am looking for a tool that can produce bathymetry of a river from cross sections. Although people who may know such tools probably will not need any explanation why this kind of ...
0
votes
2answers
346 views

Difference between Geostatistical analysis and Spatial analysis tool for interpolation

I did interpolation on point data using "Geostatistical Analyst" tool. It gives me surface layer. Then I exported this layer into raster image (by right click on this layer=>export data into raster) ...
10
votes
5answers
335 views

What is the best technique for interpolating soil depth from sample points

This is my first post here. I have some points from a soil depth survey and I need to interpolate the depth for a whole area. What is the most appropriate technique for this and is there anything I ...
1
vote
2answers
312 views

How to batch process (100s) of interpolations in QGIS or other open source software programs?

Is there an efficient way to run 100s of interpolations in QGIS or other open source software programs? I have groundwater contamination data collected from monitoring wells at about 800 different ...
2
votes
0answers
55 views

Interpolate current Course value of GPS using previous Course values

I have a set of GPS data with Lat, lon and Course. I need to interpolate current value of course, using previous values of Course. The formula I am using is not accurate in curves.In C language I was ...
4
votes
1answer
160 views

Is it possible to do spatial interpolation using points in a field?

I would like to use Quantum instead of ArcGIS to make field map but before, I need to know if its possible to do spatial interpolation with definited points in a field (ex. pH points). Is there a ...
2
votes
1answer
185 views

Inverse distance weighted interpolation for categorical and/or binary datasets

I want to perform an Inverse distance weighted (IDW) interpolation to a series of points. However my data set can be categorical or binary and just like the IDW I want to interpolate the new values ...
5
votes
2answers
149 views

Spatial Analysis with Factors/Classifications

When doing analysis on spatial data with associated information that is numeric, it is possible to use techniques such as Kriging or Interpolation or Cluster Analysis to find out interesting ...
11
votes
1answer
908 views

How do you use GRASS's v.kernel?

I am flummoxed on how to use GRASS's v.kernel. I have a vector layer of around 2.5 million points. I want to make a heat map using v.kernel to show concentrations, since I have variable instances ...
5
votes
3answers
688 views

How to interpolate into polygons?

I need to interpolate values from points to polygons. I have a point shapefile and a shapefile of adjacent polygons. Some polygons get several points falling inside, some have nothing. I thought ...
4
votes
1answer
213 views

Interpolation of Values in ArcGIS

I wanted to interpolate the trend values (trend of sunshine hour calculated over 20 years) throughout the study area from the available station points. My confusion is in the selection of ...
7
votes
6answers
623 views

Shortest Path using interpolated OSM points

I have a set of GPS points which I have snapped to the OSM network. In the below screenshot GPS points are red, snapped points are green. I want to calculate the shortest path that includes all of ...
5
votes
2answers
338 views

Spatio-temporal block kriging with R package gstat?

In the documentation of sp I saw that the coords argument of the SpatialPolygons function only accepts 2 columns. Is it not possible to create 3-dimensional polygons? I am doing spatio-temporal ...
4
votes
0answers
41 views

ArcGis Raster Resampling Question [duplicate]

Possible Duplicate: How do you decide what interpolation method to use for resampling raster data? I want to interpolate a certiain target variable over a large territory. I trained a ...
2
votes
1answer
635 views

TIN Interpolation using a vector layer

I'm writing a plugin in QGIS and I'd like to generate a TIN surface using a vector layer with x,y and z (interpolation attribute). The idea is to visualize the same result like in the Interpolation ...
9
votes
3answers
992 views

Interpolation for timeseries in ArcGIS

I'm trying to calculate average rainfall value from a number of points using Inverse Weighted Distance tool in ArcGIS 9.3. My problem is that: each point has it own time series, therefore the ...
11
votes
3answers
406 views

Modelling of rent prices - which interpolation method should I choose?

I have national dataset of ~1,4 million households. There I have information about rent, size (number of rooms and m2) and some additional characteristics of each household. I'd like to use this data ...
3
votes
0answers
76 views

Is there a way to create raster by interpolating point values using GeoTools 8.2?

im new in using GeoTools (8.2). I was able to create shp from asc file which contains my data. Now my question is is there a simple way to create (interpolate) a simple shapefile (only points) to ...
5
votes
1answer
457 views

How to choose raster interpolation method?

I work with a dataset of ~1.3 million residential buildings; each of them is described by a normally distributed variable ranging from 0 to 100. The dataset covers whole Switzerland so there are ...
5
votes
2answers
409 views

How to interpolate while providing clipping geometry? (ArcGIS 10)

Is there a way to interpolate (IDW) while providing clipping geometry? My objective is that I want to interpolate temperature data but I do not want it to interpolate the entire extent of the point ...
5
votes
1answer
228 views

Change the image size in ARCGIS

I did interpolation operation on temperature and precipitation data. Output image size is 3300 (col) and 2550 (row). I have some NDVI images with size of 15456 (col) and 5074 (row). Generally, I want ...
4
votes
2answers
140 views

3D modelling a snow patch

In my studies, I work with the internal dynamics of different snowpatches. In this study I wish to generate 3D models of snow patches. I have some problems when it comes to the actual work flow of ...
3
votes
0answers
80 views

Which geostatistical tools to use to determine surface changes over 40 years?

I have a data from the Weather station with SWEmax (snow water equivalent) collected over 40 years. I need to interpolate the data over my river's watershed and then, somehow, determine the ...
0
votes
0answers
42 views

Displaying Interpolated surface [duplicate]

Possible Duplicate: Displaying/Accessing interpolated data I successfully carried out IDW interpolation procedure on rainfall data, using the spatial extent, same pixel size, and same pixel ...
10
votes
3answers
854 views

How to interpolate GPS Positions in PostGIS

I have a PostGIS table of GPS positions for every five seconds: 2011-01-01 00:00:05, POINT(x1,y1) 2011-01-01 00:00:10, POINT(x2,y2) 2011-01-01 00:00:15, POINT(x3,y3) ... I'm looking for a query ...

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