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

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1answer
121 views

How to add information to an attribute table?

I'm working with qgis 1.8.0 and did the following: 1.-Divided my shapefile into 830 features (small rectangles). 2.- Added to my shapefile several points containing weather information using the "add ...
0
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0answers
450 views

Code to compute weights for Inverse Distance in C#

I want to test my data using IDW in C#. As I am new to C#, can someone please help me by providing the code to compute the weight for the point?
5
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2answers
300 views

Which kriging method is the best for the rainfall?

I am working on an rainfall analysis and I have to interpolate some datas with kriging method. So is co-kriging the best one for the rainfall analysis?
0
votes
1answer
51 views

Sampling from interpolated data layer

Im working with QGIS 1.8.0 and wanted to ask you how can I assign to each of the small squares of the map (I have the coordinates of the center each of them) values from an interpolated data layer as ...
-2
votes
1answer
154 views

Interpolation of data

I'm new with the program and I want to know if I can use it for my master thesis so I was trying it out and have the following question: Is it possible to interpolate data out of 5 weather stations ...
0
votes
1answer
108 views

Problem with interpolation of 3D points in GRASS

I have a sample of 3D points (x,y,z) with tepmerature attribute. I can import my data as a 3D vector map. I want to create a volume of voxels by using v.vol.rst. When I use this module, this error ...
0
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1answer
346 views

Convert / interpolate delimited text csv points grid to surface

I've got 12 delimited text csv files with regular pseudo-gridded points for temperature and salinity which look like this when zoomed in (inc distances) and this when zoomed out. I'm trying to convert ...
0
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0answers
371 views

Which is the best interpolation method for collected ground water sample?

I have collected ground water quality samples from 50 locations in my study area. Now I have to interpolate data in ArcGIS. Which is a suitable method for ground water interpolation and why?
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2answers
651 views

How can I get an error map of an interpolation in ArcGIS?

I have about 10 point shapefiles containing a lot of points each. (I would prefer not to join them into one shapefile, it's pain). And I am using interpolation method Topo to Raster to create a DTM. ...
1
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0answers
666 views

Error #010067 when running spline interpolation

I am attempting to run a spline interpolation on a point dataset of 585 features in ArcGIS 9.3, using the spatial analyst toolbar. The dataset holds only latitude, longitude and abundance attribute ...
0
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1answer
174 views

interpolate point values to line

This might be a stupid question and I apologize if so. I have count data for different trails. They are points and I would like to make an average of those counts for each trail so that each trail has ...
4
votes
2answers
148 views

How to (vertically) register a DEM to GPS readings?

I don't know if what I ask is possible or not but let's try... I have two datasets: a DEM as a point cloud in a relative coordinate system, constructed with 3D algorithm structure-from-motion. 20 ...
0
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1answer
227 views

Tools in the Sextante toolbox in QGIS 1.8 for interpolation?

What tools in the Sextante toolbox in QGIS 1.8 can be used for interpolation (kriging and spline)? I have looked at every single one and could not figure it out.
1
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0answers
644 views

Validation of Regression Kriging

I am interested in exploring the idea of generating a predictive model for a target variable in a spatial context. I would then like to correct the residuals of this model using kriging, i.e. in a ...
4
votes
0answers
96 views

Estimation of values for unsampled points

I want to measure biomass on a coastal mudflat. I can only access points inside the polygon. Are there any methods available that would allow me to estimate values of the points outside of the ...
1
vote
0answers
488 views

Source code for interpolation using a known set of random points in an area of land

In a fixed area of land random points with their values are generated. I need to get a heat map for this area of land showing the variations using those known point values. I have found that mostly ...
1
vote
1answer
321 views

Diffusion/Kernel Interpolation with barriers? [closed]

I need to interpolate water quality data in a rather small area with peninsulas, islands and developed coastline that will act as barriers between my testing/sampling points. I understand I have to ...
0
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0answers
115 views

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

I have ecological sample data collected from 5 locations within a 133345678.5678 sq meter area. The data is stored in a point shape file. I have joined tabular data with the point layer by duplicating ...
1
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0answers
55 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
216 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
1answer
394 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 ...
1
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0answers
121 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 ...
6
votes
1answer
462 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 ...
7
votes
2answers
347 views

Should point data be equidistant projected when using ArcGIS IDW spatial interpolation?

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 ...
1
vote
1answer
253 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
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0answers
178 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 ...
0
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4answers
185 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 ...
3
votes
1answer
539 views

“Topo to Raster” tool for QGIS?

is there any analogue of the ArcGIS "topo to raster" tool 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
501 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 ...
3
votes
1answer
336 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 ...
1
vote
1answer
90 views

Transforming Lat/Long NASA points into raster for ArcMap?

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? ...
13
votes
1answer
3k 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 ...
5
votes
1answer
1k views

Interpolating Maps - Statistical Learning Techniques vs Spatial Statistics Techniques

I have recently begun experimenting with the interpolation of variales over a whole country. I have good sized training set where I have several dependant variables (continuous and categorical) ...
2
votes
1answer
380 views

How to obtain closest point of point over polylines layer in PostGIS 1.4 (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 ...
2
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0answers
141 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
343 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
560 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
624 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 ...
4
votes
1answer
530 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 ...
5
votes
1answer
494 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 ...
4
votes
0answers
53 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 ...
0
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2answers
2k views

Difference between Geostatistical Analyst and Spatial Analyst toolboxes 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) ...
12
votes
2answers
649 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 ...
6
votes
3answers
788 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 ...
2
votes
1answer
3k 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 ...
4
votes
1answer
357 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 ...
3
votes
0answers
193 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 ...
7
votes
1answer
1k 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 ...
4
votes
2answers
202 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 ...
4
votes
4answers
935 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 ...