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

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4
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0answers
71 views

Interpolating species data from sample points in a small area

I have sample data from a small site (10 acres) which shows the number of occurrences of a particular species of snail over two sampling periods (fall and spring sampling). I want to try and ...
4
votes
0answers
290 views

Weather conditions forecasting / interpolation

I'm trying to carry out weather conditions interpolations. I have information of 92 weather stations for 800,000 km2. As you can imagine the extension of land is huge and I need some kind or weather ...
4
votes
0answers
93 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 ...
3
votes
0answers
22 views

Preparing data for semiovariogram analysis in ArcGIS with large sample sizes?

I am working on a statewide project to create surface water quality grids from point samples. In some instances, we have large sample sizes (n>50,000) which is problematic when creating ...
3
votes
0answers
63 views

DEM from contours

I have problem to create a DEM from contours. I know it is very simple but I can not make it work. I tried everything but nothing has happended! The shapefiles I've got are a con_lin and a con_pol ...
3
votes
0answers
47 views

Elevation interpolation along a (sewer) line

Here's what I want to do. I have a vector sewer line feature class that contaings a field for the high invert elevation and one for the low invert elevation. I can turn them into a raster no problem ...
3
votes
0answers
26 views

3D distance and topography

I have a set of points and want to find out the nearest distance to a water body (poly lines) taking into account the terrain and get a surface distance calculation. I understand that the way is to ...
3
votes
0answers
71 views

Validity of ordinary kriging of polygon centroids

I'm in a discussion with a colleague who believes that kriging should not be used to interpolate a surface from polygon based data (i.e. with kriging applied to centroids), because this effectively ...
3
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0answers
165 views

Empirical Bayesian kriging - does data need to be normal?

With empirical Bayesian kriging (ebk), does the data need to be normally distributed? If I apply a normal score transformation, my data is still not normal. Is ebk kriging thus an invalid ...
3
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0answers
248 views

Create a path following a road, interpolating from a set of points

I have several hundred vehicular routes within a city from which I wish to create shapefiles. These take the form of directions such as "From Green Street, turn left into Brown Street, Right into ...
3
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0answers
184 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 ...
3
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0answers
124 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 ...
2
votes
0answers
37 views

3D interpolating

Our final year project domain is soil contamination modeling. We collected soil samples at the depths of 0.3 cm ,0.5cm , 1cm , 1.5 cm in about 25 locations. We considered 8 contaminants- p h, sodium, ...
2
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0answers
27 views

Isolation and interpretation of vineyard multispectral data

I have 3 band multispectral raster imagery over a vineyard from which i have created a number of indices e.g. NDVI. The data is fairly high resolution (5cm/pixel) so shows a lot of along vine and ...
2
votes
0answers
29 views

How to remove spikes from grid in SAGA GIS?

I tried to get a grid by interpolating LAS file using Ordinary Kriging. But the product grid has many pixels which values strongly stands out from average surface - I mean one pixel sinks nad spikes. ...
2
votes
0answers
97 views

best method for gridding or interpolating elevation data

I wonder if someone can recommend the best method for gridding elevation data in QGIS, GRASS or similar. The elevation data I have is collected along 1m spaced lines at approximately 1 reading per ...
2
votes
0answers
50 views

How to Interpolate very large datasets in QGIS?

I am working with a very large set of point data, (XYAttribute) which I wish to display as a raster. I've been using Interpolate, this is successful but very slow. I have other programmes that ...
2
votes
0answers
218 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. ...
2
votes
0answers
131 views

How to calculate the grid point precipitation from the station data?

I have a problem to convert my hourly station precipitation data to the surrounding grid points. I need to convert 4 station hourly rainfall data to 18, 60, and 240 grid points for 0.0625,0.03125, ...
2
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0answers
475 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 ...
2
votes
0answers
136 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 ...
1
vote
0answers
22 views

Calculate surface map from PostGIS

We need to create surface maps from the website. The data is stored on PostGIS (2.1) as a table of Point geometries with a field indicating a thematic value. The optimal solution would be to produce ...
1
vote
0answers
15 views

Problem with QGIS raster interpolation from a point shapefile after duplicating the shapefile

Let me explain a problem I had with QGIS to see if somebody else has experience it. I created a raster from a point shapefile through the Raster-> Interpolation menu with no problems. After that, I ...
1
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0answers
39 views

Does interpolation create a vector or raster?

I have been reading about interpolation and am trying to understand whether interpolation results in a vector or raster. Say I have a layer of points and I am interested in creating a raster that fits ...
1
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0answers
6 views

Finding polygon from two arcs using CLI tools or some library

I'm trying to convert from textual representation into a set of arcs and lines. The 'input' I have is: The area is within lines joining two semicircles with a radius of 0.67 NM centred on: 641139N ...
1
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0answers
24 views

Optimal distance and power exponent in IDW

I want to apply IDW interpolation for my region of interest, and through leave-one-out cross validation I want to find the optimal values for the distance parameter and the power exponent. I know that ...
1
vote
0answers
33 views

TIN Interpolation in QGIS creates weird lines?

I am using TIN Interpolation to interpolate point features based on their cost attribute (value is between 0 and 5000). Graduated symbology creates something like this: However when I am using TIN ...
1
vote
0answers
25 views

Interpolation of SRTM data

My situation: I need to interpolate the 3" srtm data for a game I'm developing (it's like Minecraft - voxel style). I downloaded the srtm data from viewfinderpanoramas.org. My aim is to get the height ...
1
vote
0answers
29 views

Hydrological triangle (geoscience) with QGIS 2.6.1

I want to interpolate ( TIN-Interpolation) between variable points (the best within a triangle) WITHOUT producing new shapefiles (or csv data file). So what I have now is an interpolation of all ...
1
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0answers
20 views

Is there a standard for determining the accuracy of a polygon interpolation technique?

I'm looking into polygon interpolation, and was curious if there are any standards for determining the accuracy of polygon interpolation techniques. I've been looking through papers and lecturers ...
1
vote
0answers
21 views

How to draw a surface with Natural Neighboring

How can I use the natural neighbouring method with JAVA API of ArcGIS? I mean that I have points and z values of these points and I want to interpolate these values on an arbitrary map.
1
vote
0answers
39 views

How to include 3D break lines in QGIS raster interpolation

I wish to add a break line to an interpolation of a set of survey points to simulate an elevated ridge in the survey area. Using QGIS 2.6 on Windows 7. I have created a polyline shapefile with a ...
1
vote
0answers
44 views

Maxent output clips to minimum extent of all input variables

I am experiencing an issue with the spatial extent of my output ASC files. I am using the UK Land Cover Map (LCM) 2007 at 25 metres resolution as a categorical variable in my Maxent modelling, ...
1
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0answers
61 views

GIS grid linear interpolation for a given point

Suppose that I have a GIS grid. I need to do linear interpolation for a given point located inside a cell of the GIS grid. The locations and values of the vertices of each cell in the grid are ...
1
vote
0answers
79 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 ...
1
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0answers
80 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 ...
1
vote
0answers
1k 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 ...
1
vote
0answers
64 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
0answers
83 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 ...
1
vote
0answers
74 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 ...
1
vote
0answers
136 views

Interpolating shapefile of points to grid using Java?

I am looking for a method/prog/library(java) to interpolate points from a shapefile to a grid (file). I have seen arcgis can do that but i am looking for something free. More specific: i have ...
1
vote
0answers
606 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 ...
1
vote
0answers
597 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 ...
1
vote
0answers
460 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
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0answers
54 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
0answers
113 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 ...
1
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0answers
171 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 ...
1
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0answers
133 views

How to interpolate values sampled at regular time intervals?

I want to numerically integrate a set of discrete values that keep arriving at constant time intervals. Which interpolation method do I choose? how to reduce the ringing artifacts if I use cubic ...
1
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0answers
531 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 ...
1
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0answers
709 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" ...