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

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4
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1answer
488 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 & ...
18
votes
3answers
798 views

How to count consecutive pixel values for a set of rasters?

I'm using ArcGIS 10 with Spatial Analyst. I have a set of rasters (8 in total) that only every contain a 1 or a 0 for each cell. Each raster represents a different years worth of data. For arguments ...
5
votes
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 ...
1
vote
1answer
252 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
votes
1answer
263 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 ...
6
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2answers
4k views

Reclassify raster values of 9999 to NoData, leaving all other values alone, in ArcGIS Desktop?

I have a raster in ArcGIS which has a number of cells with the values 9999, showing that the data could not be generated for that cell. I want to convert all of these 9999 values to NoData, so that ...
4
votes
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 ...
2
votes
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 ...
2
votes
1answer
185 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 ...
3
votes
2answers
157 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 ...
7
votes
2answers
3k 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, ...
3
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0answers
541 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 ...
1
vote
1answer
673 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 ...
0
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0answers
227 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 ...
9
votes
3answers
1k views

How to combine corner-touching polygons into a single feature

I have created a polygon layer from rasters, and only have a single classification ID (and calculated acres) for each polygon. I would like to "dissolve" all touching features into larger, individual ...
2
votes
2answers
3k views

Raster Combine - ESRI Spatial Analyst

I am trying to combine a whole bunch of rasters with Esri Spatial Analyst. Seems to be doing what I want EXCEPT the calculated output is only the area where all 4 rasters overlap. I am a complete ...
1
vote
1answer
621 views

Aggregate Data between Polygons

I have data at the ZIP3 level and I need to join it to a state file. I also need the data within the zip3 file to be averaged, but for some reason when I use the join tools, i'm not getting the ...
1
vote
2answers
304 views

Spatial Analyst - Contouring a range only

I have a grid (in .img format) with pixel values ranging from -10,000 to 10,000, which i would like to contour. but i would like to contour only -3000 to 0 range. is this possible to set this up ...
13
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3answers
2k views

How does Nearest Neighbor Image Resampling work in ArcGIS?

I am trying to understand how nearest neighbor for the resampling of Image datasets works in ArcGIS. The output raster cell value is the value of the closest cell value in the input raster: In this ...
2
votes
1answer
556 views

Spatial Analyst tool Look up but in ArcView3.2

Is there any option how to do a Spatial Analyst tool "Look up" operation from ArcGIS 10 in ArcView 3.2? I have a grid with attributes and need to "extract" values from the table field (values from ...
9
votes
3answers
882 views

Creating raster by randomly choosing cell value from multiple overlapping rasters?

I'm using ArcGIS Desktop 10 with its Spatial Analyst extension. How do I combine multiple rasters into one, always choosing randomly from the values of overlapping cells? I have an image that may ...
7
votes
2answers
2k views

Can shaded relief be “blended” with DEM colour ramp in ArcGIS to produce a more visually dramatic result?

Not being able to use true transparencies with ArcGIS colour ramps where only solid colours are allowed has me always wondering about how to improve the look of the surface in my maps without ...
5
votes
1answer
553 views

Creating field with specified slope projecting from 3D polygon?

I am trying to figure out how to create a elevation raster from a known location (3D polygon) that projects at a specified slope (1%) for a specified distance(1-2 km). Does anyone have any idea how ...
5
votes
1answer
441 views

How do I get the upstream distance to all points in a DEM from a single downstream point?

I want to get the upstream distance to all points in a DEM from a single downstream point. The goal is to create a "downstream distance to a point grid". This then would allow me to create "distance" ...
0
votes
3answers
5k views

How can I add the Spatial Analyst ArcToolBox?

I tried to add the Spatial Analyst ArcToolBox by right click and selecting 'Add Toolbox' but I cannot find in any folder the available toolboxes. They seem that they have disappered. I work with ...
17
votes
3answers
785 views

Dealing with bridges and tunnels when modeling raster least cost paths?

I'm currently using ArcGIS 10 Spatial Analyst's Cost Path tool to model pedestrian routes. I have sidewalks, fences, buildings and a ton of pedestrian scale features, all combined into a cost surface ...
6
votes
2answers
910 views

What are best practices to compare densities and locations between two sets of points?

I have two sets of point shapefiles. They represent two different customer groups for a retail store. Shapefile A represents online customers, Shapefile B represents in-store customers. What I ...
3
votes
1answer
1k views

Conditional reclassification of a raster

I am attempting to do a conditional reclassification of an NLCD land-use raster. I specifically want to reclassify all developed areas (classifications 22,23,24) that are near a road (classification ...
4
votes
1answer
2k views

How do I add a hyphen to the Field Calculator to merge 2 columns?

I am trying to build a field calculator expression to merge two columns into one. I am looking for the word that makes it a range. Example: I have 2 columns in elevation, From and To. I want to ...
3
votes
1answer
574 views

How does cost allocation work?

Why, when I use the cost allocation function of Spatial Analyst, is space not allocated in all input source locations (as shown in image below)? In particular, the input raster has 18 spots while the ...
1
vote
2answers
670 views

arcpy.sa.Viewshed with OFFSETA

This is using ArcGIS10 arcpy with spatial analyst. I need to call Viewshed, but with an observer height set. I have tried using a Z-aware point feature set, but that only throws an error. I am ...
0
votes
1answer
241 views

Specific Spatial Analyst tools failing while running extension using ArcGIS server

I am having having trouble running ExtractValuesToPoints on a remote server machine running ArcGIS Server (with ArcInfo and Spatial Analyst installed). It fails and throws a standard COM error. I have ...
6
votes
1answer
928 views

Are special interpolation techniques required for weather data?

I've downloaded a series of weather observations from the local weather agency - it comprises around 1,000 points spread non-uniformly across Australia, with a greater density of points located near ...
4
votes
2answers
2k views

How to exclude outliers from raster using ArcGIS for Desktop?

I calculated terrain curvature from a DEM. The DEM I use is interpolated from point elevation data. Generally, the DEM seems to be good, but some artifacts from interpolation exist. Those artifacts ...
3
votes
1answer
749 views

Strange Behavior in Focal Statistics

I am trying to calculate the maximum value in a neighborhood on a raster using the Focal Statistics tool for Spatial Analyst in ArcGIS 10. Using python, I loop though several different radii, with ...
15
votes
4answers
2k views

Where can I find examples of fuzzy logic applications in ArcGIS?

The last ArcGIS version (10) includes two arctoolbox tools for fuzzy logic (Fuzzy Membership, and Fuzzy Overlay). Does anyone know where can I find some examples showing how they can be applied? ...
8
votes
3answers
1k views

How to cluster points based on a kernel density?

I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
3
votes
2answers
337 views

Performing statistical analysis of buffers?

I am doing a buffer analysis of incinerators and looking at the output areas within those buffers, is there a way of doing a statistical analysis of several buffers to see if there is a significant ...
5
votes
1answer
383 views

How to find upstream - lateral and downstream zones around urban areas?

I've a DTM and a shapefile of built-up areas. For a fire risk model, I've to find (within a defined buffer zone) two zones around built-up areas: one that is above/higher and lateral and the other ...
1
vote
3answers
601 views

What other tools can complete this exercise besides ArcGIS Spatial Analyst?

excel spread sheet here The objective in the exercise is to determine how many public computers are available per person as a result of spatial distribution of libraries and people. Part 1: Grid of ...
1
vote
3answers
2k views

Calculate XY Coordinate with “CalculateField” tool

I used model builder to build a model which can calculate the XY coordinates and it's perfect! However, when I export it to VBscript and run it in VBA it crashes.... The error happens at ...
4
votes
2answers
1k views

Solar radiation calculation gives Background processing has encountered serious error and is unable to continue?

I have tried to calculate solar radiation (whole year with monthly interval) for Portugal from an ESRI grid (27m DEM) in Arcgis10. It seems to work, however it takes much more than a week and in the ...
9
votes
1answer
13k views

creating a dem from contours

I have a large set of contours that I received broken down into several different subsets. I have merged most of the subsets together creating a larger set of contours in three different files. I have ...
5
votes
1answer
353 views

Merging two DEMs in different pixel bits?

I have 2 different Digital Elevation Modeling (DEM). One is the state DEM and has 30m and has 16 pixel bit. I have a couple of smaller DEM that has 30m but they have 32 pixel bit. I know how to merge ...
2
votes
1answer
438 views

Making RasterToASCII_conversion observe environment setting for output cell size?

I have two rasters (an ESRI grid and an IMAGINE image) that differ in projection, extent and cell size. I want to convert the IMAGINE to an ASCII, and want it to have the extent, cell size and ...
3
votes
1answer
805 views

Solar radiation calculation from GTOP030 DEM image

Can you help me to calculate solar radiation from GTOPO30 DEM image at the 30 m spatial resolution. I'm trying to do this many times using spatial analysis solar radiation calculation tool in ArcGIS. ...
1
vote
2answers
412 views

Using ArcGIS API interpolation functions (idw, kriging, splines) in my own dataset?

Does ArcGIS API provide interpolation functions, like if I want to interpolate from my own set of values? I know that ArcGIS provides functions for interpolation like IDW, Spline and Kriging etc, ...
4
votes
1answer
1k views

How do I know if the DEM has z values?

How do I know if the DEM contains z-values ? By looking at the DEM's layer properties and it does not mention the z values. I then add it to the ArcScene and tried to find it..nothing... It only ...
6
votes
3answers
5k views

Finding nearest raster cell value based on vector point?

I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
0
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0answers
693 views

Watershed / drainage network analysis; floating point or integer raster for input?

I am a little desperate to find a solution to my problem. As I have detailed in this post I am unable to create a detailed drainage network (and catchments) from high resolution LiDAR data. I think ...