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

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3
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1answer
211 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 ...
2
votes
1answer
264 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 ...
1
vote
1answer
31 views

Interpolation of xyz data

Data has been given to us in a HUGE .xyz file, which has been split into many component CSV files. When I upload the CSV file, then create the shape file by "save as", all is fine. When I go to ...
1
vote
1answer
44 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 ...
1
vote
1answer
38 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 ...
1
vote
1answer
50 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, ...
4
votes
0answers
180 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
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0answers
86 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
25 views

Spatial interpolation with breaklines in R

I have a dataset consisting of irregularly-spaced points (x,y,value) that represent an area of ocean that contains some land. I need to interpolate these to a regular grid, ensuring that the ...
3
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0answers
31 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
161 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
139 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
111 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
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0answers
60 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 ...
2
votes
0answers
184 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
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0answers
96 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
359 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
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0answers
104 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
46 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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0answers
243 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
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0answers
41 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
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0answers
65 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
368 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 ...
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0answers
423 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
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0answers
313 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 ...
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0answers
48 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 ...
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0answers
74 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
143 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 ...
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0answers
271 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.
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0answers
124 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 ...
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0answers
451 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 ...
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0answers
647 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" ...
0
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0answers
10 views

Raster Analysis Grid (Interpolation) Crashes

Upon clicking on "Grid (Interpolation)" QGIS crashes. I running QGIS 2.2.0-Valmiera on a Mac with OS X 10.9.4 Thank you for any trouble shooting guidance
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0answers
12 views

Manipulating Interpolation Outputs

I would like to clip the edges of my interpolation output to cover only a specific Local Study Area and also combine the output with a DEM to create a spatially defined 3D model in ArcGIS 10.1. Two ...
0
votes
0answers
43 views

Choosing appropriate Interpolation Tool

I am interested in doing some fairly simple interpolation work in the next few weeks using ArcGIS 10.1. However, I am unsure about which interpolation tool is most appropriate for the task at hand. ...
0
votes
0answers
23 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 ...
0
votes
0answers
65 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, ...
0
votes
0answers
11 views

Convert ECF to Suface ECF

I'm using the 3D Earth WorldWind Model and I have a path that I want my object to travel. I set the the destination and interpolate to the end point from my current location. The problem is using ECF ...
0
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0answers
11 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
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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
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0answers
137 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 ...
0
votes
0answers
220 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: ...
0
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0answers
60 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
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0answers
145 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 ...
0
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0answers
95 views

Weather interpolations QGIS

does any one know how good are the weather interpolations that QGIS carries out? Do you have any other suggestions or better methods to do them? Please let me know. Thanks in advance!
0
votes
0answers
118 views

memory restrictions in QGIS Interpolate?

I am trying to make a DTM from contour lines (.SHP) using the Interpolate tool. The tool runs fine when I clip the data into smaller areas, but when running for larger areas, it crashes QGIS. Are ...
0
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0answers
74 views

Mapping point data according to it respective value

The project I am trying to do is to map sum water quality (based on trace metals) data into QGIS. Each of the trace metals have their respective values and need to represent their concentration ...
0
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0answers
255 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?
0
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0answers
232 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?
0
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0answers
87 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 ...