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

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98 views

Why is interpolation adding too much heat

I am interpolating geo data using qgis. The data is in the form of lat,lon,count. The path of the collected data is shown as a mostly transparent line. The resulting heatmap it produces is shown. ...
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2answers
212 views

Why do the range of values change when I export geostatistical layer to raster?

I did an interpolation of soil pH using 232 data points in geostatistical analyst with IDW, RBF and ordinary kriging. For all 3 methods, the range of pH values change (become smaller) after I export ...
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1answer
303 views

How to treat missing values as null

I have an excel file with missing values encoded as blanks and I want this excel file to be converted into DBF but with the conversion process, the blanks (missing values) become 0. The reason I am ...
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1answer
424 views

DEM to point file & interpolation

I have a DEM which has noisy parts to it. I am trying to (eventually) calculate the volume. However when I do cut/fill, there are obviously white sections where it hasn't been able to calculate the ...
2
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1answer
241 views

Smoothly interpolating Polygons from set of coordinates?

I'm still quite new to QGIS and I'm using it to display and analyze my soil data. I have point information on the distribution of the soils in a specific area and I need to create a soil map from ...
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1answer
373 views

Problem with interpolating a vertical profile in 3D Analyst (ArcMap 10.1)

I have a problem when I want to create a vertical profile in 3D Analyst from a DEM file. I want to interpolate the data and show points from 20 to 20 meters, as I specified in the option panel (see ...
2
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1answer
362 views

How to add an interpolation raster from the python console in QGIS?

I'm trying to add an interpolation layer based on an existing vector layer by using the Python Console (initially in the menu Raster/Interpolation), but can't find anything related in the ...
3
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1answer
947 views

Three-dimensional interpolation of temperature profiles using gstat in R?

I'm working on a problem in which I'd like to interpolate a set of oceanographic temperature profiles over a three-dimensional matrix of unsampled x, y, & z locations. The data to interpolate is ...
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1answer
98 views

Iterative interpolation

I have an excel file with about data from 600 locations, each location having data for 1200 months(12 months* 100 years). I need to interpolate all point locations into rasters for each month of each ...
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0answers
79 views

Spline interpolation - 3D analysis [closed]

From the help document, spline interpolation is supposed to produce a surface runnin through the exact input point. i have about 100 point and run spline interpolation. i also extract the interpolated ...
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1answer
405 views

How can I take a large netcdf and convert it to interpolated values in a different set of coordinates?

I've got a large netcdf (a small portion of the data is here) with the data in an even grid associated with an Albers Equal Area Conic projection. I've got the corresponding latitudes and longitudes ...
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1answer
331 views

Why do I get these bands on my Height/Dem/Raster

I can't seem to get rid of them, and I've no idea (ok scrap that, I have a vauge idea) whats causing them. First an apology, yes this is quite a large pic apologies, but here goes: How to ...
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0answers
135 views

Issues creating slope raster layer from a point layer

I'm trying to create a slope raster layer using QGIS 2.0 on Windows XP. I started with a points layer with the Z elevation attribute. I then used the interpolation plugin to create a DEM. But, ...
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1answer
186 views

Interpolate points to lines every odd and even number

We are working in Oracle Database 11g. There is a table with sdo_geomerty column(representing a line) which contains the following : RSID, LT, LF, GEOM 584908, 30, 34, ...
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0answers
132 views

network based interpolation methods, which one could I use?

I need to interpolate traffic data consisting in raw number of vehicles passing across certain points, where counters are. It is evident I haven't a uniform distribution of points and values about ...
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2answers
537 views

Color gradient in symbology in ArcGIS 10.1 for interpolation raster

I have measured noise and want to create with this measured points a noise map with interpolation....is there any way in symbology to create a flowing transition between the different colors for the ...
2
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2answers
628 views

How to interpolate population data?

I have population data (inhabitants per city and year) of 31 cities of the DR Congo for the years 1960, 1970, 1980 and 1990. I want to interpolate the population of all cities for the year 1990, to ...
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0answers
611 views

Error when kriging in SAGA: grid file could not be opened [duplicate]

I have a point and a polygon vector shape (shapes) which I want to interpolate by using the saga tool "Ordinary Kriging". I always get the following error message: Oooops! The following output ...
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1answer
167 views

problem in spline with barriers in ArcGIS 9.3?

I am trying to use the script tool "Spline with Barriers" from arcgis 9.3 3D Analyst toolboxes. I am not getting expected output. The output is just only one value over the surface. We are using ...
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2answers
182 views

How to perform IDW interpolation and mean estimation on county level using ArcGIS for Desktop?

I am absolutely new to GIS. I have imported a map with information in the counties of Germany. Additionally I have added a layer with information on SO2 concentration at various measuring stations in ...
4
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2answers
409 views

Interpolate Temperature Using DEM

I want to "co-interpolate" temperature with DEM. I have SRTM 90m aggregated to 1km and I want to "co-interpolate" my DEM with points with temperature data. How do I do this? I am using ArcGIS 10.
4
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1answer
694 views

Interpolating vertically in 3D analyst

Here is my problem: I am working on mapping pollutant concentrations in a pond from point-sampled data. There are 50 sampling locations in the pond (randomly dispersed), and at each location there ...
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1answer
249 views

How to Interpolate through ModelBuilder?

I would like to create an iterated interpolation tool through ModelBuilder. I have an excel file containing different columns and each column represents a data that will be interpolated using Spline ...
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3answers
665 views

Which interpolation method for noise mapping?

I want to create a noise map with measured point data. But i want to have a planar representation, so I need an interpolation method. Which one is the 'best' one for measured noise data? I prefer to ...
3
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1answer
738 views

Interpolating contour lines from TIN-model vs Grid in ArcGIS for Desktop?

I am a complete beginner in GIS and taking a class right now, and we are doing some assignments in ArcGIS - ArcMap. In one of them we were given a shapefile with heightpoints. These had been manually ...
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2answers
1k views

What's wrong with my IDW interpolation function (Python)?

Original Question Can anyone see what's wrong with my custom IDW interpolation below? I know there are existing libraries that can do this for me, but for various reasons including educational and ...
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2answers
577 views

References to code IDW algorithm

Hi I'm new to interpolations. I'm looking for documentation to understand how inverse distance algorithm works and how to code it. My intention is to code IDW algorithm in JavaScript to see if it is ...
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0answers
139 views

Statistically compare two density maps?

I (will) have a modelled distribution and an observed distribution of animals. If I were to interpolate these position datasets to reflect some density distribution (perhaps using a kriging ...
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1answer
111 views

QGIS 2.0 Raster Interpolation

I am trying to use the Rasterinterpolation plugin to pick up elevations from a Raster DEM for a series of vector points. Once loaded, the Plugin is accessible through Plugins Menu/ Raster ...
4
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1answer
216 views

What are duck egg patterns in weighted moving average spatial interpolation method?

I'm dealing with spatial interpolation methods, in particular with the weighted moving average. I come across really oft with a term "duck egg patterns" which are caused by isolated data points. ...
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2answers
632 views

Breaklines in QGIS interpolation plugin

How can I prepare data to generate a DTM using points and breaklines, but where every breakline has nodes at different heights. For example, a river valley, which regularly falls, or a dorsal line, ...
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2answers
49 views

attach point grid data non-grid points

Possibly a strange one: I have a dataset with loads of fields of environmental (explanatory) data, as a regular grid of points (black dots in image), and another dataset of sampled (response) values ...
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1answer
61 views

“Interpolation Toolset” is inactive in ArcGIS for Desktop 10.1

I have ArcGIS for Desktop 10.1 installed on my laptop and "Interpolation toolset" and "Raster Interpolation toolset" is Inactive. How can I get them work?
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4answers
655 views

What are the most efficient Geographic Weighted Regression packages?

What are the most memory efficient open source packages for calculating a geographically weighted regression (GWR)? I am in a situation where I need to do a geographically weighted regression on a ...
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1answer
404 views

Difference spatial interpolation and trend surface analysis

What is the difference between spatial interpolation and trend surface analysis? For example, I read a scientific study that applied a neural network to estimate a surface solely based on the x and y ...
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0answers
2k views

smoothing results from scipy griddata interpolatioin

I am using the griddata interpolation package in scipy, and an extrapolation function pulled from fatiando: import numpy as np import scipy from scipy.interpolate import griddata import ...
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2answers
2k views

How to interpolate a point vector layer inside a boundary (polygon layer) QGIS/GRASS/SAGA?

I have a to create a heatmap of water temperatures inside a lake for which I have sample points. The map should look much like the climate maps generated by climate change models. I have the ...
3
votes
2answers
371 views

How to set lower limit to interpolation?

I have rainfall data that I want to interpolate using spline. I have done Spline Interpolation, only that the values produce negative predicted values which is basically wrong. There should be no ...
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0answers
382 views

How to write Python script for spatial interpolation?

I am new to Python. I have 5 rainfall stations in a basin of 1400km2, and I want to interpolate the daily rainfall series for 14 years. I spent a long time on this, but am unable to write a program ...
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1answer
9k views

When to use IDW vs Kriging Interpolation for DEM creation?

I'm trying to create a DEM using point data spaced very regularly about 10m apart. The area I am interpolating is an educational facility with many flat parking lots and football fields but still has ...
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3answers
422 views

Extract data to file after performing kriging interpolation in ArcGIS

For 3 meteorological stations, I created maps by Kriging Interpolation tool to extract data for other places. How is it possible to extract a data file (Excel or text) from this interpolation? (this ...
2
votes
1answer
211 views

Cross-validation of TPS and kriging outputs from the fields package in R

I am looking for existing package or functions that will allow me to cross-validate multiple outputs of Thin plate spline (TPS) and Kriging from the fields package. Does anyone know of any available ...
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2answers
54 views

Which value should I assign my digitalized features?

I have a scanned an old document that contains geochemical interpolated values (no way to work with the digital file). This is the original image: And this is the digitalization I made from it: ...
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0answers
113 views

Qgis raster interpolation shift

Using Qgis 2.0.1, I'm attempting to interpolate a large point dataset (n > 400K) to a raster surface. I'm using the IDW option in Raster>> Interpolation>> Interpolation, and the resulting ...
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0answers
472 views

SAGA/GDAL fails to open grid in QGIS 2.0.1 on OSX 10.6.8

I want to try different grid/raster spline interpolation methods using SAGA in QGIS. I'm using the kyngchaos build 2.0.1-7 for Snow Leopard. Every SAGA algorithm I try gives the following in a popup: ...
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1answer
117 views

Finding points on an odd map projection using interpolation between known points

I have an image of a somewhat idiosyncratic projection that is a frame from a film: A geographer friend of mine said it was probably some kind of Gnomic projection, but that from the resolution it ...
4
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1answer
370 views

Debugging errors of SAGA interpolation algorithms in QGIS 2.0 Processing

I encounter recurrent problems with the geoalgorithms that perform interpolations. No matter technique I use I end with the following errors. As state in OGR tab QGIS is unable to open a file in C ...
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1answer
190 views

3 points meteorology stations

I want to extract meteorological data of a point which are 3 meteorological stations around it. I found that ArcGis has the capability to do it by interpolation. My essential data is wind speed , ...
3
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1answer
2k views

How to pick the coefficient in Inverse Distance Weighted method?

I'm using QGIS 1.8.0 to interpolate weather data. This is, I have a weather station located in say, A and C. With the Inverted Distance Weighting or Triangular Interpolation methods, I can ...
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2answers
107 views

What ArcGIS interpolation tool would be most appropriate for price/square meter?

I have the price per square meter of around 13000 properties ; for the other 8000 of my shapefile the price is missing. The easiest option is to transfer the average price per square meter to the ...