All Questions
441 questions with no upvoted or accepted answers
11
votes
0
answers
1k
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 ...
- 51.8k
4
votes
0
answers
379
views
How to increase Compression Memory for ECW Opacity Builder
I am attempting to build opacity within an ECW file using ECW_Opacity_Builder.exe from APOLLO Essential Utilities 2014, which has worked flawlessly many times before.
When attempting to build opacity ...
- 25.7k
4
votes
0
answers
756
views
How to remove black pixels in Landsat image
Does anyone know how I can remove these black pixels around the edge of this Landsat image? They appeared when I layer-stacked the bands in ERDAS IMAGINE - they were not there in the separate band ...
- 861
4
votes
1
answer
384
views
Is r.cost equivalent to diffusion interpolation with barriers?
I want to perform interpolation using cost distances rather than euclidean distances similar to Greenberg et al. (2011). In that paper they use r.cost in GRASS to compute cost distances for each ...
- 49
3
votes
0
answers
166
views
ArcPy raster Reclassify not covering all cells in raster
I am trying to use Reclassify on 240 rasters using ArcPy within the Python window in ArcMap 10.7. My original raster has continuous decimal probabilities ranging from 0 to 1, and my goal is to change ...
- 523
3
votes
0
answers
507
views
Using RemapRange for Reclassify in ArcPy gives ERRORS 000622 and 000628?
I am trying to reclassify a raster, "Conifer_Focl", which lives in inputData.gdb. The max value for "Conifer_Focl" is 33.217064. I'm looking to reclassify as:
I am following the instructions from ...
- 916
3
votes
0
answers
273
views
Extracting cells from raster by attribute in ERDAS Imagine
I have a raster file that gives me the slope of all the hills and mountains in an area in degrees (0-90) and I need to extract all the cells which are >= 45 with an operator in the model builder. I ...
- 113
3
votes
0
answers
57
views
Need to run a Groundwater Analysis Based on Points to a Raster
The title sounds daunting, but this task really isn't. I have well samples over a decade in certain locations through an area. These samples contain a value of that element at that point in time. I ...
- 4,387
3
votes
0
answers
149
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 ...
- 31
3
votes
0
answers
498
views
How to extract NetCDF raster values to time enabled shapefiles?
Does anyone know a good way to extract NetCDF raster values to each data point from a time enabled shapefile at the correct time?
I have tried using a python script tool and a loop that steps ...
- 33
3
votes
1
answer
2k
views
Using Python script to stack layers from multiple directories and produce multiple outputs in ERDAS?
I am using ERDAS Imagine 2013 and am trying to create a Python script that takes lists created in another script containing the path to each scene's raw data folder and base image ID's (for example ...
- 151
3
votes
0
answers
354
views
Calculating surface elevation from DEM of pit and known volume with which it is being filled using ArcMap
I am using ArcMap 10.1.
I have a DEM of a pit.
I have a known volume of material that I want to put in the pit.
I want to know what the elevation of the flat surface of this material will be once it ...
- 449
3
votes
0
answers
3k
views
Interpreting 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 ...
- 659
3
votes
0
answers
503
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 = ...
- 4,229
3
votes
0
answers
158
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 ...
- 31
3
votes
0
answers
1k
views
Performing Multicriteria Analysis Using Distance Along 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, ...
- 22k
2
votes
0
answers
174
views
Iterate over a list of raster with Arcpy and apply Con() to each raster
I would like to iterate a list of raster objects and apply Con() to each raster. The rasters are in a specific order in the list. That's important. All I want to do is to write the value of the ...
- 527
2
votes
0
answers
44
views
ArcPy producing wrong slope map using Spatial Analyst with ArcMap
I wrote a Python script which is supposed to produce a slope map with 6 classes each one being from 0-3.99, 4-9.99, 10-15.99, 16-30.99, 31-60.99, 61+ (Although for testing purposes the max is 789.54). ...
- 45
2
votes
1
answer
218
views
Zonal Statistics as table on population raster does not produce correct regional population figures using ArcGIS Pro
I have a population raster (from Worldpop.org) with data on the population count of Philippines. It is unconstrained data from 2020, 100m resolution.
Link to raster: https://www.worldpop.org/geodata/...
2
votes
1
answer
155
views
Getting the percentage of points within an area
I'm new to ArcGIS and trying to gather the number of points and a percentage of those points within a somewhat small area. How would I do this or what would this be called? Spatial query? I have ...
- 21
2
votes
2
answers
820
views
Finding longest flow path in multiple basins at once using ArcGIS Pro and Spatial Analyst
In my watershed I have around 400 basins. I need to find the max flow length in each basin. The "Flow Length" tool creates the flow length for the entire watershed, not for each individual ...
- 166
2
votes
0
answers
54
views
Using LiDAR-Derived DEM to Identify Aerial Sewer Lines
I am trying to come up with the best process for identifying aerial sewer lines (typically over streams) using the pipe inverts and a LiDAR-derived DEM. In other words, locate the lines where the Z ...
- 41
2
votes
1
answer
1k
views
Calculating spatial correlation between two datasets using ArcMap and Spatial Analyst
I am using ArcMap and the Spatial Analyst extension.
I am trying to find a correlation between my raster datasets. For example, for Net Primary Production (NPP) model I used too many input datasets ...
2
votes
0
answers
118
views
Do PNG files suffer performance for scaled read over ERDAS Imagine (.img) files?
So I have a 20 GB in size Raster Image in .img format. Though I will be examining the code, to find out why, I am AMAZED at how quickly QGIS renders the entire file in a scaled format, and prior to ...
- 21
2
votes
0
answers
31
views
Find Optimal Subset of Feature Layer Based on Spatial Criteria & Attributes
I'm using a Census tract shapefile with their corresponding attributes of interest within ArcMap 10.7.1.
My project goal is to identify the subset of tracts that share a line segment while:
...
2
votes
0
answers
172
views
Choosing observer points for Viewshed tool in ArcMap to identify visibility of landform
I am using ArcMap 10.8.
I want to create a polygon that shows all the areas within a region from which an observer could see a specific mountain.
I created a polygon around the mountain, and I'm going ...
- 101
2
votes
0
answers
470
views
Understanding units in Kernel Density analysis using ArcMap
I'm having trouble understanding the units from a Kernel Density analysis in ArcMap.
The Context: I am analyzing how many structures will be damaged by sea-level rise in a coastal community. I have ...
- 21
2
votes
0
answers
128
views
Contour lines from AutoCAD to QGIS: how to automatically assign the right value to the Z
I have a plate of contour lines made on AutoCAD (contour lines do not have a Z). The Z is indicated only for some curves but in a text format.
If you import the table in QGIS the situation is this (...
- 648
2
votes
0
answers
66
views
Solving color correction of LISS IV Multispectral image
I have a LISS IV multispectral images (radiometric resolution of 10 bit per pixel) taken in different months 4 tile in January and 2 tiles taken in February.
While mosaicing, I got a different color ...
- 21
2
votes
0
answers
388
views
Spatial similarity between polygons
I am using PostGIS and python3. I have a table with polygons objects, the polygons have year as an attribute. I need to identify the uniqueness of the polygons trough time. For instance I need to ...
- 21
2
votes
0
answers
727
views
Error 999999, Table name is invalid - Zonal Stats as table
I am attempting to run a model that iterates rasters and computes zonal statistics returning a table. The raster's statistics are computer across all polygons in a specific shapefile. This model ...
- 452
2
votes
0
answers
694
views
Layer stacking Multispectral reflectance imagery in ERDAS Imagine 2016
I have Green, red, Red edge and Near infra-red reflectance maps captured with a Parrot Sequoia camera and post processed with Pix4D.
They are all Single Float Tiff files, around 500Mb in size.
I ...
- 65
2
votes
1
answer
581
views
Multiple buffer ring area analysis using ArcGIS Pro
I have some sites what I've created multi ring buffers for in one shape file, each ring is 50m from the center up to 1000m. The file is one shapefile with many polygons and each ring is the full size (...
- 21
2
votes
0
answers
114
views
Writing Raster Calculator Expression?
I use ArcMap 10.3.
How do I create an expression in RasterCalculator that allows me to sum up 4 rasters (every pixel has an associated value) and the result to be 0 if any of the 4 values is 0?
For ...
- 21
2
votes
0
answers
96
views
Least cost path from visibility
I use ArcGIS 10.1 and I am dealing with viewshed and least cost path analysis. I would like to generate a path on the basis of a cost surface taking into account the viewshed data as indicated in the ...
- 71
2
votes
0
answers
862
views
Choosing bandwidth and scaling factor for Kernel Density Estimate in ArcGIS Desktop?
I have some points that represent animal locations over the course of a few months at the scale of ~20 sqkm. I am emulating the work of previous researchers in this field, but I'm having trouble ...
- 61
2
votes
0
answers
77
views
Preventing ArcGIS Desktop from creating 64-bit rasters?
I've run into this issue recently wherein I run the Con tool on a 32-bit raster (TIFF format) to change some absurdly high/low values to 0 and I get a 64-bit raster (TIFF format) out the other side. ...
- 453
2
votes
0
answers
648
views
Why is Raster Calculator not honoring compression environment settings?
For some reason, the Raster Calculator isn't honoring any Raster Storage environments that I have set. Mainly, compression and pyramids. I am processing a large raster dataset through raster ...
- 448
2
votes
0
answers
359
views
Calculating indices such as NDVI or NDSI on Landsat 8 imagery whose pixel type is 16 bit signed integer?
I am trying to calculate an NDSI (Normalized Difference Snow Index) using Landsat 8 OLI level 1 imagery atmospherically corrected in ERDAS ATCOR using raster calculator in ArcMap. NDSI is used to to ...
2
votes
0
answers
81
views
Simple iterate SetNull in ArcPy not working
For a large number of rasters, I need to define a pixel value less than zero as being Null and output the rasters. However, my simple SetNull loop (below) only processes the first raster in my list as ...
- 21
2
votes
0
answers
36
views
Adding small-extent rasters to DEM
My goal: create viewsheds for observers which also incorporate the heights of buildings which could block observer view. This is using archaeological data, and is representing time change -- so I need ...
- 81
2
votes
0
answers
82
views
Obtaining a smoothed DTM?
I am use AcGIS 10.1 and have a DTM with an 8 m grid resolution. Which tool could I apply to smooth the surface?
- 71
2
votes
2
answers
832
views
Projection shapefile
I created a shapefile of Sundarban area Bangladesh. Here it is:
Here is the projection information about it:
I want this shapefile to project upon an image which is here [I downloaded it from ...
- 129
2
votes
0
answers
44
views
Cost back link tool
I am trying to use cost path analysis to create a least cost path from ports around the UK to various offshore locations. To do this I have created a cost raster grid with values of 0 for land and 1 ...
- 21
2
votes
0
answers
81
views
Combining Rasters
I am working on making a dual density map currently in ArcMap. I've conducted kernel density for my two sets of points, one of which contains incidents, the other residencies. What I want to do is ...
- 31
2
votes
0
answers
77
views
ArcGIS Visibility <NoData> / 0 when observer point in raster cell center
As I discovered, the ArcGIS Visibility tool seems to produces a vertical line from the observer point northwards in the above ground level raster and a 0 value in the visibility Raster, if the ...
2
votes
0
answers
367
views
Raster calculator: Missing areas in output using two mosaics
I'm doing a simple DEM minus DSM to get tree canopy heights. However my results are missing most of the data (no data).
I've used the Minus tool and Raster Calculator achieving the exact same result. ...
- 79
2
votes
0
answers
67
views
Focal statistics using geodesic distance in ArcGIS Desktop?
I need to compute focal statistics (sum, mean etc.) for raster data spanning the whole globe. I want to use a constant radius e.g. 100km around each cell.
However the data are geographic (WGS84), so ...
2
votes
0
answers
68
views
How to create a surface area that interpolates and visualizes trends in physical activity in ArcGIS?
I have a dataset that contains several hundred telemetry points for my focal species around twilight hours. Attached to these points are mean values that represent how active the animal was 10 ...
- 117
2
votes
0
answers
204
views
Create Gaussian dispersal kernel raster
In ArcMap 10.4.1 I would like to make a raster with a simple Gaussian distribution away from a central point - as in the image below. It does not need to be 3D, simply higher values at the centre and ...
- 31