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

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4
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1answer
42 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 ...
1
vote
1answer
87 views

Interpolation with netcdf4 file

I have a netcdf4 data set that contains array and information about latitude and longitude which can be accessed with the following R command: ncvar_get(dataname, 'lon'); ncvar_get(dataname, 'lat'); ...
-1
votes
0answers
24 views

Interpolation of cross-shaped data [closed]

What is the best interpolation method for data deriving from a cross-shaped sampling design (picture)?
1
vote
1answer
38 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 ...
1
vote
4answers
69 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 ...
2
votes
1answer
228 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 ...
3
votes
2answers
131 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 ...
4
votes
1answer
68 views

GIS beginner - interpolating contour lines from TIN-model vs. Grid in ArcGIS

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 ...
0
votes
0answers
7 views

Printing a label from a point layer attribute on a raster layer (GRASS)

I am interpolating with boundaries using v.surf.idc in GRASS. It works wonderfully and I fully recommend it. I am creating an animation and I use v.surf.idc to generate sequential interpolated raster ...
0
votes
2answers
36 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 ...
1
vote
1answer
30 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 ...
1
vote
2answers
17 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 ...
1
vote
2answers
89 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 ...
1
vote
2answers
62 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, ...
4
votes
1answer
56 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 ...
1
vote
1answer
28 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?
0
votes
2answers
277 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. ...
0
votes
1answer
51 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 ...
1
vote
0answers
119 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 ...
4
votes
0answers
81 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
2answers
40 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 ...
0
votes
0answers
16 views

Interpolation Plugin Not outputting image?

I am trying to get terrain profiles from shapefile elevation points by creating a TIN. I have been following this very helpful tutorial. At the output a new layer is created but with no ...
0
votes
0answers
81 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 ...
5
votes
1answer
199 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 ...
0
votes
1answer
135 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 ...
14
votes
2answers
1k views

What resampling technique should be used when projecting aerial photos?

I'm doing some time-intensive projecting of aerial photos, and I'm curious - what resampling technique is best to use on aerial photos? In ArcMap, my options are NEAREST, BILINEAR, CUBIC, and ...
1
vote
0answers
29 views

TPS and Kriging Cross-Validation

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 availabe ...
1
vote
2answers
45 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: ...
0
votes
0answers
147 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: ...
7
votes
2answers
240 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 ...
3
votes
1answer
111 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 ...
1
vote
1answer
45 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 ...
1
vote
1answer
74 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 , ...
4
votes
2answers
119 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
votes
0answers
183 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?
1
vote
2answers
69 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 ...
2
votes
1answer
69 views

How to integrate DEM in Kriging and other interpolation methods?

I would like to see the difference of including DEM in interpolation from without. Some studies on climate data interpolation suggest that interpolation performs better with DEM. How do I do this in ...
4
votes
1answer
61 views

How to add points to LAS copy using liblas?

I am trying to make a copy of a LAS file while inserting new points using python liblas module. The code below creates the copy and adds the points, but for some reason the added points are not in ...
0
votes
0answers
49 views

Interpolation without a point layer in QGIS

I have a vector layer with incidence data (i.e. frequencies) and I made a graded color map from this using the above frequencies. Now I am looking forward to creating an interpolated (kriging) map ...
2
votes
1answer
247 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 ...
28
votes
9answers
8k views

Open source methods for kriging?

I have a point dataset which I'd like to Krige, ideally using an open-source software package. If possible, I'd also like to choose the semi-variogram model during the process to improve the ...
0
votes
0answers
54 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
0
votes
0answers
103 views

Interpolate/disaggregate point values to an existing raster grid

I have several thousands of ASCII files whose names have the following format: data_"lat"_"long".mon (e.g. data_41.21875_-116.21875.mon). Each file represents one point in WGS84 projection and the ...
1
vote
0answers
58 views

Interpolating counts within irregular-shaped regions in a country?

GIS novice here. We are trying to estimate the total number of toxic waste sites within the country of Ghana. We will be dividing up the country into quadrats (with some irregular shapes on the ...
3
votes
2answers
101 views

How to connect contour lines from two different sources?

How to connect contour lines from two different sources (LiDAR & Photogarametry) in order to obtain continuous and uniform contour lines layer ? how can i interpolate them together ? How can i ...
4
votes
2answers
156 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?
2
votes
0answers
155 views

how to make decent sense from scattered river depth measurements

I sampled river depth at scattered positions and I want to be able to make a map and GIS layers out of it. My problems are: As the river meanders the interpolation I do in scientific packages i,e. ...
1
vote
1answer
41 views

Is it possible to specify interpolation method for zoom functions in Styled Layer Descriptor (SLD)?

To visualize images on Geoserver, I use xml file wrote in Styled Layer Descriptor (http://www.opengeospatial.org/standards/sld). I would like to specify what interpolation method would be used for ...
0
votes
1answer
60 views

How to consider more than one no data value in utility gdalwarp of GDAL

I have to do a bilinear interpolation on an image with two no data values, using the utility gdalwarp of GDAL (http://www.gdal.org/gdalwarp.html), so these two values don't must be considered in ...
1
vote
0answers
410 views

Using ArcGIS to interpolate X, Y, Coordinates and ordinary kriging of point data

I have been using Geosoft's Target to interpolate X, Y coordinates then use them to create grids using ordinary kriging. I am now working with ArcGIS which I am new to and cant seem to be able to ...