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

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91 views

Neighborhood analysis based on occurrence of value

How can I do, either in ArcGIS, grass or another tool, the following: for each cell (pixel), if there is at least one cell with value '4' in a neighborhood of 5 cells around it, reclassify that cell ...
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0answers
745 views

What does “You do not have necessary license to run tool” mean when ArcGIS extension installed and activated?

I just purchased ArcGIS for Home Use 10.2 and installed and activated the extensions with the codes I received from Esri. The ArcGIS Administrator says Yes for Installed and Authorized, and even has ...
3
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2answers
88 views

how to change the pixel value to zero when it corresponds to a slope above 15%

i have a landuse raster data and raster data containing slopes in percentage. i want to assign pixel value as zero which corresponds to slope more than 15%. i tried using 'extract by mask' but i'm ...
3
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1answer
303 views

How to exclude stations from IDW interpolation?

I have the following problem: I need to calculate an average precipitation amount on a catchment using an IDW interpolation. The interpolation is performed in a loop since each precipitation station ...
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1answer
834 views

How to change the pixel value of a raster dataset which overlaps a polygon featured shapefile in ArcGIS

I have a raster data of 1992 and a 'shapefile' of Los Angeles county. I want to reclassify the pixel value of the raster data set to 'no data' or zero in the region where the raster and the ...
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1answer
196 views

How can I define hierarchical levels in eCognition

I'd like to define classes with 2 levels. Firstly I'm gonna classify some broad classes such as forest, grassland in a level 1. Furthermore, I'd like to classify these classes into some sub-classes ...
2
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0answers
58 views

Copying an entire column between layers (tables)

I have a raster layer with probabilities as values and I process them using the Spatial Analyst extension. After the processing the values are modified, however I would like to also have the original ...
5
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1answer
123 views

Can 2D polygon be used as hard breakline for terrain?

I've been working with TINs for years and have only ever been satisfied when using 3D polylines for breaklines. I am currently transitioning to using terrains and after reading the documentation in ...
3
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3answers
315 views

What DEMs does QGIS support? + DEM data sample

I am working on QGIS rasters. I want to know about DEM file formats supported by QGIS. I know that QGIS can read the GDAL supported formats. but what is GDAL supported format ? Does QGIS support the ...
5
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1answer
89 views

Can I “stack” semivariogram data?

I have several synoptic measurements (every few months) of a gravity field I would like to interpolate by kriging. Each group of measurements comprises about 45 measurement locations, and spatial ...
2
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0answers
310 views

Problems with spatial autocorrelation in Geographically Weighted Regression (GWR) analysis

I have conducted an Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) analysis in ArcGIS where I have tried to predict biodiversity patterns in an area. When I examine the ...
3
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1answer
718 views

How to reclassify raster inside polygon mask, leaving values outside as they are?

I am in the final stages of a landcover classification and need to reclassify thematic raster values that are inside different polygon masks, while leaving the values outside as they are. Can I do ...
2
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1answer
75 views

Examining the covariance between biodiversity and other variables

I have som problems with an analysis and would be very grateful for any answers or suggestion. The background is: - I want to examine the covariance between ecosystem services in an area. I don´t ...
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0answers
310 views

Question related with NDVI value on water

There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
4
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0answers
199 views

Tabulate Area ArcGIS

I am trying to work out the relationship between the 'processing cell size' and the result from Tabulate Areas. If one uses the same as the raster cell size, and this is the same for both rasters, the ...
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1answer
29 views

What is the meaning of “MULTIPOLYGON EMPTY” Message?

I am trying to run ST_Intersection function. SELECT ST_AsText(ST_Intersection(ST_Point(42.729123082000058,-96.619302355999992), ST_Point(42.72899715300008,-96.619410439999967))) FROM clu_08aug; I am ...
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1answer
211 views

ArcGIS TabulateArea() :: Recommend Ratio of Zone Area to Value Raster Cell Size?

Any recommended ratio of zone area / raster cell size when running small input zones with ArcGIS Tabulate Area Tools? Esri mentions: If the zone input is a feature dataset with relatively small ...
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2answers
544 views

Using Regression Trees in ArcGIS

Hi I have a follow up question to this post: Statistical analyses for survey against raster? I have a very similar problem as the initial poster David. I am creating a multivariate model from ...
0
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1answer
123 views

What Z-factor to set in Curvature (spatial analyst)?

I'm making a slope curvature map, my DTM is 5*5 meters cells, in a meter grid projection. The elevation is in meters asl. When using the Curvature tool for different units of measure, the Z-factor has ...
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0answers
313 views

How to Smooth Polygons after converting DEM using Raster to Polygon?

I have a DEM SRTM that I classify using Spatial Analyst Tools > Reclass > Reclassify. The result is box shaped so I go to Layer Properties > Display and choose cubic convolution. The result is ...
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1answer
257 views

Overland flow modeling Help

I would like to determine the surface flow network, this based on the spatial analysis of DEM data and the creation of separate layers for surface ponds and preferential surface flow pathways. More ...
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2answers
57 views

how can I find sDNA toolbox for arcgis?

I am working on spatial structure of the city and security. I need the sDNA Toolbox to add in gis toolboxes. please help.It is a real emergency.
6
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1answer
350 views

How to find nearest neighbors of polylines?

I have a shapefile containing irregularly placed polylines (i.e., survey routes). Following the general idea of a paper I read, I would like to use tessellation to identify the neighbors for each ...
7
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3answers
240 views

How to compare spatial patterns (crime cases vs population)?

I am looking for a way to statistically compare two spatial patterns in shape polygon data (not point pattern analysis). Let's say I have a city map divided in neighborhoods (barrios), in shape ...
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0answers
159 views

How to calculate Gradient from DEM?

I have a digital elevation model for a catchment area and I would like to calculate the gradient by cells. Is that possible and does anybody know the steps?
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0answers
37 views

Problem in analyzing data in a stream segment

I have to find out the head difference along the stream segment. For that I used Spatial Analyst Tool>Extraction>Sample. With that I got the elevation values in points. But after doing so, i found ...
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2answers
167 views

Site Selection using Spatial Analyst

How can I select a recreation site location based on the criterion that it should AT LEAST be 500 m from a river (shapefile) and AT MOST 15000 m from the same river using Spatial Analyst Extension? ...
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3answers
1k views

How to perform a view shed analysis?

I want to run a viewshed analysis on a site I am interested in. I have the relevant elevation raster (taken from the OS UK, which is in the ASCII format) and a point feature class from the lat/lon ...
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2answers
208 views

How to modify 2 raster images to have the same resolution?

I have data for 2 rasters images that have different resolutions: z downloaded from trmm An MSAVI2 output image. For calculating the correlation between them, the data has to be in the same ...
2
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1answer
370 views

Where can I get documentation for Netezza Spatial Functions

I am looking for some documentation or manual or reference guide for Netezza Spatial Functions. Any idea where can I get the same. Thank you. Dharmesh
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0answers
247 views

How to use Zonal Stats as Table tool with in-line variable substitution

I have created a model to iterate a folder of 5 shapefiles to apply the Zonal Stats as Table tool to a raster. My output table is saved as table%i% so i'm expecting it produce 5 tables (table0, ...
2
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1answer
576 views

Better way to get raster values for a large number of point features?

I have several projects with tree point features (SpecialStatusSpeciesPoint) that contain up to 2,000,000 records. I am trying to record tree height (Hgt) and base elevation (BaseElev) values, based ...
2
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1answer
274 views

Are there Open Source alternatives to ArcGIS Aggregate and Extract Value to Points?

I am looking for some kind of Open source GIS library which can perform spatial analytic functions same as ArcGIS. My use case is : I am processing GeoTIFF file provided by USGS and performing ...
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2answers
389 views

How to create a raster (topo to raster) with non-rectangular shape?

I'm using Arcmap 10, I need to create a raster from contour lines. These contour lines were clipped out with a certain shape with the purpose to modify them only within that shape and then create the ...
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1answer
101 views

How to make a new raster out of two other rasters [duplicate]

I have two raster images, one is the Corine Land Cover for the year 2000 and another one which is the anthropogenic effect on land. The first image reclassified in 9 categories: Artificial surfaces ...
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0answers
157 views

ArcGIS Spatial Analyst “Sample” returns Null values

Using "sample" to join raster values onto point data, some of my points get assigned a Null raster value. The raster does not contain Null values and definitely looks like it has a value at the ...
4
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1answer
220 views

Shortest raster path

I am trying to create a path from the blue square to all the green dots. The blue square represents an existing road and the green dots represent centroids of forest stands. The total path distance ...
3
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2answers
357 views

scratch files left behind by arcpy.sa.Con

I have a Con() statement that creates two "extra" scratch files during it's processing, but that do not get cleaned up once the operation is over and the output is saved. r=arcpy.sa.Con(elv, ...
2
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2answers
816 views

Arcmap 10 restrict Flow Accumulation

I am working with the Flow Accumulation tool in ArcMap 10's spatial analyst hydrology tools. This tool calculates the total number of raster cells that flow into a given cell. However, for my ...
1
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1answer
358 views

How to run a shortest path analysis for DEM-derived streams and pour points?

I have a .shp for streams and another for pour points. Those features were extracted from a DEM by using the Hydrology package from the Spatial Analyst Tools of ArcGIS 10. I want to know the distance ...
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1answer
75 views

Near / Near Table creates -1 values

I have two feature classes. Point feature of hand-sampled GPS locations Line feature of terrace walls digitized from aerial photograph. Because of the less than perfect ways I generated these ...
0
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1answer
415 views

How to run a ZTV (ZVI) on ESRI ArcGIS 10 for a 3m high object?

What tool in the spatial toolbox would you use to run a ZTV (ZVI)? or is there a better way of carrying this type of query out using Arc? Also what other information would I need to do this type of ...
3
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0answers
189 views

Determine 3 and 6 minute fire response times

I'm expecting to get an Excel file with data on previous fire and emergency response times. I was told it will have incident addresses and the response time for each incident (~ 12K incidents). I also ...
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1answer
605 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
3
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3answers
2k views

How can I reclassify a raster to floating point values?

I have a raster of landuse values that I need to reclassify into pollution concentration values. I have the pollution values in a separate table. They are decimal values (ex. 0.0056), and my landuse ...
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0answers
245 views

How to create backlink raster for Cost Distance tool?

I have two polygon shapefiles and one cost surface. I need to estimate accessibility to these two sets of destinations. The part that I don't understand is whether I have to use an output backlink ...
2
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2answers
291 views

Tabulate Area crashes Python and ArcGIS

I have a script that runs Tabulate Area on a single feature class multiple times with different rasters. In total Tabulate Area runs 5 times. 2 of the input rasters are provided as arguments to the ...
2
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0answers
139 views

Different results from Spatial Analyst GP Tool and Python

I am writing a script that has to subtract one raster from another. The rasters I have represent 1) Parking Lots (1 = Parking Lot, 0 = not Parking Lot) and 2) a buffer around the Parking Lot (1 = ...
2
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2answers
77 views

Solar analysis; Are there any issues with splitting large DEM

I am trying to run Solar analysis in ArcGIS and it is an enormous DEM of a very mountainous region. I'm obviously going to have to split the DEM, but I was wondering if there are any issues with ...
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1answer
90 views

territory analysis

I want to determine the territories in which customers to a bank has the shortest path. It can be done with desktop software packages or programming if it is needed. Does anybody has idea on how to ...