Spatial Analyst is a extension within ArcGIS that provides a range of spatial modeling and analysis tools.

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How to Create Multiple Start and Destination Cost Paths?

I have a suitability matrix which was created in model builder based on elevation data and multiple start data points and end data points representing schools. I'd like to link all the schools up ...
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3answers
2k views

Extract Overlapping Polygon Data to Points

I have a polygon data set of corn yield collected by a combine. However, as the combine drove through the field, there was slight overlap between passes, leading to overlapping polygons within the ...
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1answer
314 views

An error in raster calculator in Arcgis

I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
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4answers
198 views

How to determine if all points on a map are identical in arcpy?

My eventual goal is to automate kernel density calculations for a large corpus of point data; however, if all points are identical (for example, if there are 7 points all stacked on top of one another ...
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2answers
1k 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) ...
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449 views

ArcGIS Kernel Density with polyline, search radius / bandwidth calculation

I'm conducting a density analysis of a series of polylines and I'm hung up on determining an appropriate search radius. The default calculation performed by arcgis is to take the shorter dimension ...
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134 views

Spatial Analyst's CostPath toolbox/function has PATHCOST of 0 when using in_memory workspace

I have a point feature and am interested in finding the least cost path between two points in the feature using a raster as the cost surface. I first calculate the cost distance and cost backlink via ...
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1answer
2k views

Extract Values to Point from Raster Issue

I am trying to use the tool Extract Values to Points on a File Geodatabase raster, but I am getting some weird errors. I've used this tool multiple times before with no issue, but not since I ...
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1answer
232 views

Are there any rules of thumb for the neighborhood settings in Focal Statistics?

In ArcGIS 10, users can define the neighborhood in the Focal statistics tool. The moving window shape can be set to any of the following: Wedge, annulus, circle, rectangle, irregular, and weight. ...
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111 views

Does the Calculation of Spatial Weights Matrix in ArcGIS take into account 3D?

This question is about Spatial Weights Matrix in ArcGIS. Does it take into account 3D or not? I want to calculate Spatial Weights Matrix with SPACE_TIME_WINDOW. Anton
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1answer
92 views

sa.fill creates NoData raster in standalone script ArcMap 10.0

I am trying to put together a geoprocessing workflow in Python, and I've hit a stumbling block with sa.fill. When run as a standalone script, the tool produces a raster composed entirely of NoData ...
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1answer
337 views

how to obtain elevation points for a road using contour?

I have contour lines, & roads centerlines feature classes, I need to get points with elevation in the starts, intersections, & the ends of the roads, how can I get this information? I used the ...
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103 views

Distribute gridded data to corresponding subbasin boundaries

I have one ArcGIS shapefile of my river basin consisting of many subbasin. Another shapefile showing the location of gridded points over the whole basin (Its latitude and longitude are used as file ...
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2answers
453 views

Why does Raster Calculator return GRID ERROR-Unable to open the input grid: 1+FLOATC:\document…?

I'm calculating Simple Ratio (SR) from NDVI using Raster calculator in Arcgis. Here is expression I wrote in Raster calculator. SR=(1+float[NDVI_apr.tif])/(1-float[NDVI_apr.tif]) But when I evaluate ...
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381 views

What is the convergence threshold for ArcGIS Iso Cluster?

The ArcGIS tool Iso Cluster Unsupervised Classification does not seem to have any documentation on the convergence threshold used in the tool. To compare, Erdas Imagine has all of the necessary ...
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3answers
2k views

Extract raster by mask output does not completely overlap the mask

I have a flow accumulation grid and a shapefile containing catchment areas. Now I want to do some calculations on them so I need to extract data from cells in the raster adjacent to certain catchment ...
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1answer
3k views

ArcMap 10 - Extract raster cells from imagery based on RGB value

I've got some aerial photography (format: IMAGINE Image) which is detailed enough to see to fire hydrants and a shapefile of fire hydrants which was digitized based on some CAD data. My project is to ...
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2answers
2k views

How to find out the Stream Order from DEM

I have DEM Data for the study area, I want to know how to find out the stream order using DEM. I saw Stream order tool in Hydrology toolset in ArcGIS. in Stream order tool what is input stream raster ...
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3answers
1k views

How To find the Catchment Area for a Dam?

I have a DEM of my study area, and polyline shapefile of the Dams in that area. I have run the standard Hydrology tools on it( Fill, Flow Direction & Flow Accumulation). I know that you can ...
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1answer
929 views

Problem analysing movement using cost surfaces (involving ArcGIS's Path Distance-tool)

I would like to analyse hypothetical movement (on foot) in a landscape as based on energy expenditure, but I have run into some trouble that I am hoping that you could help me with. I have tried to do ...
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0answers
119 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 ...
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670 views

Performing a Multicriteria Analysis Using Distance Along a Road Network

There is the possibility that I will be working on a project which will look at thousands of properties in a region and measure their accessibility to different services (schools, parks, hospitals, ...
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1answer
383 views

GWR Result Issues

I am working with GWR to identify if there are any relationships between 'extreme' events and disease incidence. The use of GWR has been employed because I am working in a region where local ...
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1answer
326 views

Why does tool take longer to run when in Python script?

I have written a python script that does some euclidean allocation. For that I use arcpy.gp.EucAllocation_sa() method. Now, my python script takes 30-40% extra time than spatial analyst euclidean ...
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1answer
127 views

Substitute for SpatialJoin tool?

I have to write a script in Arcgis which I would like to use the SpatialJoin tool (arcpy) but I do not have the appropriate extension. It may be a tool (or example of scripts) for doing the same ...
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1answer
829 views

Modelling Sea level rise scenarios for a Coastal county in ArcGIS

I am a graduate student @ Clemson University and am working on a GIS based project which is to model different sea level rise scenarios and estimate its impacts on a coastal county and to suggest ...
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2answers
85 views

How to query points that fall outside their designated regions?

I have a shapefile with 250 points. Each point has a region attribute. In another shapefile I have all the possible regions with their names (it is polyline geometry). Unfortunately the coordinates ...
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1answer
968 views

What type of kernel density function does ArcMap use?

I know that there are several types of kernel density functions, such as uniform, cosine, Gaussian, etc. I was just wondering which one the "Kernel Density" functionality in ArcMap 10's Spatial ...
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6answers
7k views

Ways to Speed Up Python Scripts Running As ArcGIS Tools

This is a pretty general question. I just wondering what tips and tricks GIS programmers have used to speed up arcpy scripts that you import into the toolbox and run. I work most everyday writing ...
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2answers
394 views

Why would a perfectly usable raster mosaic produce an unusable clipped raster?

I'm getting funky results from Extract By Mask (spatial analyst). I'm clipping a Raster Mosaic of DEMs from the National Elevation Dataset with polygons. I have a script to run through 15 separate ...
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0answers
509 views

Output raster extents when using the Spatial Analyst Extract By Mask tool to clip a raster

I am using ArcGIS 9.2 and I have a simple python script that does the following : Loop over a polygon feature class (shown in red in the image below) For each record, create a feature layer to ...
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60 views

How do I make a path cross the most possible classes in a raster?

I want to create a function and possibly use Arcmap tools to create something similar to Cost Path. Instead of just choosing the LCP, it must cross through the most different integers. Let's say I ...
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1answer
455 views

Statistical analyses for survey against raster?

I am somewhat of a newbie to geostatistical analyses, but pretty familiar with GIS and remote sensing packages. I was wondering if anyone had suggestions on appropriate geostatistical analyses for a ...
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2answers
827 views

Floodplain generation given river section polylines, flood level elevation points and a DEM of the land surface

I am looking to generate flood plain polygons to represent 20 and 100 year flood zones, in the most accurate and efficient way possible, given the following datasets: 1) River cross section polylines ...
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1answer
1k views

Does a Zonal Statistics value change when applied on a subset of data?

I have generated zonal statistics using feature zone data on a value raster. This shapefile contains about 20000 polygons and the analysis went without a hitch. While testing quality, I ran the same ...
2
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1answer
204 views

Tabulate Area Errors

Having some issues with the tabulate area spatial analyst tool. Not sure why it's not working, but the output table is missing zones from the input feature class that defines them. I have a simple ...
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1answer
597 views

How to design a road with a certain slope

Is there a way that you want to connect two different points of altitude with a constant slope of 7% or another, to draw a line in the 3D model?
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517 views

How to assign values to a polygon layer based on nearest point in a point layer? [closed]

I have a point file depicting groundstations for rainfall measurment. I also have a polygon file representing districts of a state. I want to assign rainfall values in a particular district based on ...
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1answer
410 views

Trouble Tabulate Area

I am using Kansas Cropland raster data from NASS with tabulate area to find out acreage of different crop types. The python I used works fine for 2006-2009 (56 meter cell size), except 2010 & ...
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2answers
3k views

Viewsheds and Observer Points in ArcGIS Spatial analyst

I am trying to understand the viewshed and observer points tool in spatial analyst. I want to show which areas of land can see a wind turbine, or put another way, from where can the wind turbine be ...
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1answer
244 views

How to convert accuracy of DEM from 5 decimal places to 2

I had a csv dataset comprising of regular points containing elevation "z-values". I interpolated this using ESRI´s spatial analyst using the IDW method to produce a continuous raster surface. I set ...
3
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1answer
249 views

Estimating cline width at multiple points along a trait gradient

In the map below I have 66 (green) points along the midpoint (0.5) for an allele frequency cline across the region (see map). I created the points by placing a point every 25 km along the 0.5 allele ...
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1answer
2k views

How should I correctly exaggerate a hillshade raster (ArcGIS10, Spatial Analyst)?

I once wanted to generalize a high resolution raster and instead of MEAN i accidentally selected the default SUM technique, using a cell factor 5 (Lidar DEM is 1m resolution). When I used this result ...
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2answers
165 views

Spatial analysis? Two layers?

One is LandPlot and the other is Soils. When I open the LandPlot attribute table I see I have 500 specific plots of land. When I open the Soils attribute table I see I have 5 types of soils (let's ...
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1answer
180 views

Creating Home ranges (MCP) of marine mammals excluding solid land

I use ArcGIS 9.3 and the Hawth's tools for Home range analyses. I try to create MCP of marine mammals which all works fine. However, the MCP include some land as well. How can I create a MCP so that ...
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2answers
150 views

How to find the distance within which a set percentage of features fall?

Someone asked a question earlier about finding the number of features within a certain distance of another feature in ArcView. I have the opposite question: is there any way, in ArcGIS 10, to find the ...
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2answers
2k views

How to calculate stream order for vector data without a DEM?

I have a shapefile which contains the streams that were digitized from a satellite Image. I would like to calculate the stream order for this data. The data does not exactly match the DEM that I have, ...
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472 views

How to calculate Solar Radiation falling on vertical surfaces using DEMs and ArcGIS?

I am using ArcGIS10 Area Solar Radiation tool to calculate irradiation on horizontal surfaces (building roofs) but need to do the same for vertical surfaces (building facades). Any ideas on how to do ...
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1answer
575 views

How to use (make sense of) results from ArcGIS Area Solar Radiation tool?

I am using the tool Area Solar Radiation in ArcMap10 to analyse DEMs of parts of a city (area equivalent to a neighbourhood). My goal is to calculate the average annual solar irradiation (Wh/m2) on ...
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211 views

slope and mosaic datasets

I was wondering if anyone has had any experience with combining multiple DEM’s into a mosaic dataset. I am working with several DEM’s and need to convert them to slope. I’m having an issue with ...