All Questions

0
votes
0answers
2 views

Difference between a GNSS receiver and GNSS antenna

I´m relative new using GNSS data and I would like to understand a little more about the instruments that I´m planning to use in my future research. I was looking information on the UNAVCO website ...
1
vote
0answers
5 views

Earth Engine image export sets masked pixel values to 0 rather than NA

I'm using Earth Engine to preprocess and download some NDVI data. I used a region of interest to clip the imagery to a geometry, and values from the Summary QA layer to mask out pixels that were of ...
0
votes
0answers
6 views

Eliminating superfluous raster values

I have used the raster calculator in ArcMap to calculate the salinity index (RED-NIR/RED+NIR Khan et al.) over a portion of land which was disturbed by the construction of a solar farm. Landsat 8 ...
0
votes
0answers
5 views

Google Earth Engine:how to add date to property of images?

I mosaic images in different area. However I lost the time which is really essential to my study.
0
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0answers
9 views

Use list of attributes to create layers

I have a very long list of values (over 2000 rows) in the following format: 1: TAY100, AB60, EM10 2: CA40, 9, UT26, 24 3: YO56, YE I have a layer with features each with a distinct attribute called ...
1
vote
0answers
9 views

Finding Raster Pixel Neighbors using GDAL?

I'm new to GDAL Python, and I'm working on a little recursive algorithm which requires finding the neighbors of a a pixel on a DEM raster. I've been able to do this by creating a little PixelLite ...
0
votes
0answers
5 views

Labeling when using qgis2web

I'm having trouble getting labels to appear in a web map, both Leaflet and OpenLayers, using qgis2web. I can't get either label buffers or backgrounds to show up and even a Bold style only works in ...
0
votes
0answers
7 views

How do I crop a TIFF down to a specific region?

I have two TIFFs that have the same pixel size. One of them is geolocated inside the other. I would like to crop the larger one down to the exact same extent as the smaller one. Is this possible with ...
0
votes
0answers
5 views

self.iface.mapCanvas().destinationCrs() Replacement in QGIS 3

I need to store the map canvas' destinationCrs in a variable, but when using the following line: self.iface.mapCanvas().destinationCrs() I get the error: 'QgsMapCanvas' object has no attribute '...
0
votes
0answers
7 views

Calculate canopy openness using RGB mosaic from UAV orthorectified aerial images

Canopy openness of trees was obtained easily from digital photographs processed with Gap Light Analyzer. Image processing involves the transformation of image by the division of pixel intensities into ...
1
vote
1answer
13 views

View attribute (/field) names of a geopackage table without opening the whole file

I have a large geopackage file (15gb) for which I'd like to see the attribute (/field/column) names. Is this possible without loading the whole file? Edit: It would be ideal if there was a command ...
0
votes
1answer
15 views

Seeking CSMapMaker (QGIS Plugin) equivalent for ArcGIS Desktop?

I'm looking for a tool or script or set of operations to mimic the output from a certain QGIS plugin called CSMapMaker, wherein curvature, slope, and a gaussian filtered DEM are overlain one another ...
0
votes
0answers
11 views

QGIS: RGB image file to Y'CbCr and other Luma+Chroma Representations

is it possible using QGIS on windows to convert an RGB image file to Y'CbCr and other Luma+Chroma Representations format. I've seen various formulas for this written in MATLAB and R. I am looking to ...
0
votes
0answers
10 views

Save pictures from different files to one file

This is my code: imagePatches = glob('C:/Users/Touati/Documents/cancer_dataset/Dataset/**/*.png', recursive=True) imagePatches.save("C:/Users/Touati/Pictures/test/{}.png".format(item),"png") I get ...
0
votes
1answer
23 views

How to perform Spatial Query to remove features that intersect/touch/overlap in QGIS?

I have two polygon layers and many of the features are identical (or should be identical). I want to isolate only the features that are in one layer but not the other. I'm using QGIS 3 and I tried ...
2
votes
1answer
35 views

How to identify unknown coordinate type and convert to lat/lon?

I have some coordinates from an old Oracle database (AMANDA) and I don't recognize the format. For example, converting these coordinates: 3109020, 10114224 Should result in a point near latitude, ...
0
votes
1answer
20 views

The Add Feature Button is not present on toolbar in QGIS 3.6

This may sound crazy, but I do not have an Add Feature button on my toolbar in QGIS 3.6. Am I missing something?
1
vote
0answers
27 views

Grid rendering in QGIS?

Rendering a grid in QGIS causes problems: The outmost grid line is not drawn on different zoom-levels: Here it is ok: While here it is not ok: I have tried to change these rendering-settings, but ...
0
votes
0answers
7 views

Cannot deploy geoserver.war on Apache Tomcat

I'm very new to this so bear with me. I am trying to deploy geoserver.war through Apache Tomcat, but I keep getting the following page whenever I do: I have tried moving geoserver.war into the Tomcat ...
3
votes
1answer
32 views

Customizing QGIS plugins

Is a user legally allowed to make changes to available plugins according to his needs? e.g. changing UI, code etc but not the licenses and other info.
0
votes
1answer
15 views

Trying to use a SelectByAttribute_mangement after I made the XY Event layer

I imported a CSV file using the MakeXYEventLayer_management and trying to use the SelectlayerByAttribute_management function, but I am getting error message saying on "Object ID(OID)" is present.. Is ...
0
votes
0answers
5 views

Wrong layer analysis using GRASS v.clean tool

I am using QGIS version 3.6 in macOS Mojave, version 10.14. I am trying to fix the topology of a vector layer using the GRASS tool v.clean. The first time it worked well. I forgot to save the ...
4
votes
0answers
30 views

Python Script Performance as an ArcGIS Tool Versus Stand-Alone

Has anyone studied the difference in running a Python script in ArcToolbox versus as a stand-alone script? I had to write a quick-and-dirty script to convert a set of RGB images to single band by ...
0
votes
0answers
8 views

How to use the reducer.mean function to average multiple data points?

I am trying to figure out GDD over a period of multiple years given a period of time for each year, and the code provided below allows me to do that. Now that I have 10 years of data points, I am ...
0
votes
0answers
7 views

Mapbox Unity SDK not getting all correct building IDs from Openstreetmap

I'm developing a location based game and using the buildings as a part of the element of the game. I'm using the Mapbox SDK 2.0 in unity. Now I'm noticing on some part of the maps are loaded, but ...
0
votes
1answer
14 views

Identifying intersections in ArcPy

I have two shapefiles: one containing a single polyline feature, and the other containing a number of polygons. I'm trying to use ArcPy to identify which polygons are crossed by the line, and then ...
0
votes
1answer
12 views

QGIS Performing Table Joins returns NULL

I followed every step of this tutorial but when I join the distToRoads and distance in m I get a table distToRoads which contains just the null vaues, why is that? Tutorial: https://www....
0
votes
1answer
16 views

Replacement for legendInterface in QGIS 3

I am a novice to QGIS tasked with updating other developers' plugins from QGIS 2 to QGIS 3. Here's the code I need to replace: legend = self.iface.legendInterface() index = legend.addGroup('...
0
votes
1answer
27 views

Continuous buffer from individual polygons in QGIS

I have a stream segment for which I am trying to find a buffer around with criteria as 5m of elevation. So for each straight line within a stream segment, I have found buffer (polygon) for it. Now I ...
1
vote
1answer
31 views

Export road system to CSV file

I'm using QGIS to extract coordinates of a road network. Concretely, I downloaded a mbtiles file from Internet and loaded the file into QGIS like following: Then I tried to export the layer ...
1
vote
2answers
21 views

How to get just land and water layers in QGIS with QuickOSM?

How can I just get land and water layers that I can style with different fills and outlines? Really - Just "land is green, water is blue" layers (that I can then add other layers on top of) I'm ...
0
votes
1answer
20 views

Expression returning wrong value in QGIS Field Calculator?

My QGIS Field Calculator expression: case when "field_value" = '' or "field_value" <> NULL then (if( "field_value" = '', 'N', 'Y')) end returns null value even if "field_value" has something ...
0
votes
1answer
13 views

Defining nearest features within shapefile using ArcGIS Desktop?

In a shapefile I have around 17000 lines with different ID. I would like to give a same ID to the feature lines which are close to each other. for example in the picture : ID 306 and 305 should have ...
0
votes
1answer
37 views

Updating two or more fields in QGIS?

I have 5 layers: NAM_USA (It has four fields of our interest, named 'bare', 'sand', 'woody' and 'built' depicting feature counts in each of the below corresponding layers.) Baresoil Woodyland ...
1
vote
1answer
62 views

Exposing GRASS GIS add-on in QGIS Processing framework?

Having QGIS and GRASS GIS 7 installed, how can I expose a GRASS GIS add-on, which has been installed using g.extension, in QGIS' Processing framework?
0
votes
1answer
26 views

QGIS Join by location (summary) returns null

I am trying to count points within polygons (311 calls by Census tract). Both shapefiles are EPSG 4326, and I've done define projection just to double-check. Every time I run Join attributes by ...
3
votes
0answers
14 views

Python GeoPandas: How do I make a Shapely box larger

I'm creating a box that covers the the area of a GeoPandas GeoDataFrame, so that I can use it as an inverted map to later cover up unwanted spill-over data. import geopandas as gpd import geoplot as ...
1
vote
0answers
13 views

Spatial join for closest features and using a sum merge rule in QGIS

I am trying to perform a spatial join based on nearest neighbor ("CLOSEST") spatial relationship in QGIS, and by summing the results of the join where multiple matches occur. In ArcMap there is a way ...
2
votes
0answers
23 views

Measures of printed map in QGIS

I created a simple map with a point and a buffer (3 km) in QGIS2.18 (and also 3.4) with CRS WGS84 UTM33. With QGIS Composer I created the layout adding the scalebars (for 500 m and 3 km) and printed ...
3
votes
2answers
88 views

QGIS virtual layer functionality does not seem to support memory layers

I have a memory layer loaded in the QGIS virtual layer in the data source manager. I am trying to run a very simple query: select * from layer Here is a snapshot: While this works for the physical ...
0
votes
0answers
36 views

Making ArcPy script quicker?

The script below is used to update a shp which is missing values from another .shp using a spatial reference. It's taking about 19 minutes to run through ~53,000 rows. Any ideas on how I can make it ...
1
vote
0answers
10 views

How to apply smoothing filter only to way bigger than specified number of nodes, length, area?

I am try to smooth data obtained by vectorization of a raster image by applying a series of filters in GRASS GIS. Once of steps involves using the Douglas-Peucker filter. However, I need to apply it ...
1
vote
1answer
8 views

How to catch the event the mousePressEvent on Esri :: ArcGISRuntime :: Graphic?

All events mouse protected. I tried to do it via eventFilter and using QObject :: connect, but the result false. How do I catch a click event on Graphic? What I tried: ... void ViewshedGeoElement:...
1
vote
1answer
18 views

Extracting field value from Info table( .info ) in ArcGIS

I am working on a Python snippet try to use arcpy.da.SearchCursor() to extract value of certain field from a Info Table which generated by executing arcpy.Statistics_analysis().Here's my code: arcpy....
0
votes
0answers
11 views

Installing Psycopg2 module on linux server trough Cpanel [on hold]

I'm trying to get Psycopg2 installed on a remote server (AcuGIS) through Cpanel but I don't have root access. I found this documentation on installing the module, but can't seem to figure out how to ...
1
vote
0answers
10 views

Geo-Referencing level 1 AQUA data

I have a direct broadcast AQUA data. I used RT-STPS to extract the level 0 .PDS files and process them further to level 1A and level 1B using the modisL1DB software. These produce .hdf files. I can ...
0
votes
0answers
19 views

Can't spatial join polygons and points [on hold]

Struggling to spatial join a point layer (cell towers) with a polygon layer (states). The points layer is global, while the polygons are only within the United States. I need to eliminate all points ...
3
votes
1answer
27 views

Fixing self-connect polygon in QGIS 3.2

I'm trying to clip a soil map layer and am getting invalid geometry that affects my clip result. The problem appears to be a self-intersecting polygon. I've tried using the 'check geometries', and ...
1
vote
1answer
28 views

How can I select feature, except null values?

I want to select feature except NULL values. In the past, when I using ArcGIS, I used 'select by attributes', and type like 'NOT "field name"=NULL' But now, in QGIS, it doesn't work. Just like ...
0
votes
0answers
16 views

Comparing distance matrices in R

I am trying to compare a distance matrix of microbial communities to a distance matrix of geographic sample locations to understand if there is a distance decay relationship in my dataset. The end ...

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