Questions tagged [scale]

The ratio between distances on a map and distances in the world

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23 views

QGIS 2.18 Scale not being set up correctly

I'm working on adding scale based visibility on different layer. I'm currently using : canvas.setDestinationCrs(crs) crs.createFromUserInput(name) crs = QgsCoordinateReferenceSystem() to set ...
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1answer
29 views

How to calculate pixel size on image of map?

I have to save to .png file with part of map from app. I've got information about PPI, easting/northing, print resolution, map scale and map coordinate system and using this information I have to ...
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38 views

Adding QGIS coordinate, scale, magnifier and rotation toolbar into custom PyQGIS canvas

I was wondering if it is possible to add a toolbar with coordinate, scale magnifier, and rotation such as the one in QGIS Desktop to a custom PyQGIS canvas on a standalone application. below is a ...
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2answers
79 views

Insert a “scale box” of given side length in the QGIS layout?

QGIS allows displaying a scale bar, indicating distances. I would like to complement it with a box showing a given area, e.g. 1 hectare. How can I display this in a layout, ideally as an extension of ...
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35 views

Sentinel-3 scaling factor in Google Earth Engine

Does anybody know how to use the scaling factors from Google Earth Engine with Sentinel-3 dataset? The band values provided in ee.ImageCollection("COPERNICUS/S3/OLCI" by default (GEE, orange)...
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12 views

After export the clipped Landsat image, it's distorted

I clipped square(polygon) of NDVI and Aster GED dataset and select the scale of 100 and set CRS to native projection and Exported to drive. But when I am Opening this dataset in QGIS it's showing ...
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1answer
33 views

QGIS 3x problem with rescaling vector (shapefile) layer

I would like to rescale my shapefile layer in a particular location on my map in QGIS. Unfortunately every time my layer is rescaled in completely different location. According to this query Resizing ...
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1answer
27 views

Why is scale of image different in QGIS 3.10 than created?. CAD import and twf world file seems correct

I created an image by taking a picture of a tape measure(ruler). I rotated this image to north and made a world file .tfw for the tiff image. to get the pixel width for the twf file, I divided the ...
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48 views

Creating custom scale measurement for QGIS project

I started to make a map based on a raster (a scanned paper map). The map obviously has not geographic coordinates or a projection. The map comes with its own scale, and I would like to somehow make my ...
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25 views

Making Symbology Scales same in ArcMap

I am using two sets of data, 'Part' and 'Total'. The part set is what you would think, a fraction of the total. Part = 13 , Total = 29. I want to overlap this data on a map using Graduated Symbols but ...
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45 views

Display Features based on Zoom Level using OpenLayers

I want to display roads(linestring) on the map using OpenLayers.currently, I manage to assign styling based on road type but when I run the server I can see all the data displayed. I want to change ...
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1answer
100 views

Wrong scale in ggplot2 map

I am trying to create a political map of Morocco with regions, using ggplot2, but the scale seems to be wrong. This is the map: And below is the code I used: library(ggplot2) library(ggspatial) YK = ...
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1answer
67 views

Google Earth Engine: Converting raster to vector in the same resolution as the original image

I am using Google Earth Engine to reduce a raster region to polygon vectors. What I want to achieve is: Obtain a set of polygons each of which matches the grid of measurement in the raster dataset. ...
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1answer
40 views

Are there a list of locations or features with known dimensions?

I'm plotting lines and objects on a map and want to verify scales with real, physical objects on the map. Is there a list of physical features that are known distances? Perhaps like the runway at ...
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1answer
91 views

Min and max zoom levels/scales for a QGIS project

We've built a qgis project for use in education and we want to set up a min. and max. zoom level (or scale) for the whole project. In the project properties, we can specify some "project predefined ...
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1answer
180 views

How to calculate scale from zoom level in Google Earth Engine?

I found the following formula on the interwebs, including on some google group from someone claiming to work at Google: var scale = 156543.03392 * Math.cos(mapCenter.lat * Math.PI / 180) / Math.pow(2,...
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45 views

QGIS DXF measurements in AutoCAD are in Cartesian and not Ellipsoidal

I'm trying to export some land boundary polygons to AutoCAD using the Export to DXF function. The issue I am having is that the distance measurements in AutoCAD, of the exported DXF file, represent ...
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42 views

Map output with multiple “Zoom Levels” in QGIS 3 [duplicate]

Just wondered if it is possible to do BBC-style multiple "Zoom Levels" output in QGIS 3 like this: I used to use another app such as Adobe Illustrator to overlay the maps of different scales. ...
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2answers
64 views

How to make the display of a satellite image the same across users?

I have a group of users counting objects in a satellite image. To keep viewing conditions the same I wish each user to have the same display (e.g., the same scale). To do this, I have asked users to ...
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1answer
84 views

Scale feature in QGIS

I am trying to scale (up and down) feature(s), similar to ArcGIS where the first click specifies the scale reference point and the second click specifies the scale factor, but couldn't find a solution ...
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3answers
282 views

Re-scale and move vector layer manually in QGIS

I have imported a dxf file (site layout drawings for proposed development), but its scaling is too small and it does not line up with the google street maps. I want to re-scale the layer manually ...
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1answer
74 views

QGIS - Scale bar segments

Is it possible to divide a QGIS scale bar into different sized segments as you can in MapInfo (as with example given). Or is it possible to select different style of scale bars in QGIS? If it's not ...
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1answer
56 views

Too many pixels in Earth Engine, and scale parameter meaning

I am trying to calculate stadistics for burn areas based on the number of pixels. When running the code, GEE says too many pixels, I tried to solve it following the guides given by google developers ...
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40 views

Rescale 300 polygons within one shapefile, but keeping the original center position of each polygon

I have a shapefile type Fishnet in ArcMap, containing 300 or so polygons in it. Each polygon represent an area of interest containing plants. I have a model extracting the zonal stats of the shapefile ...
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121 views

Extracting Point data from MODIS with Sinusoidal Projection in Google Earth Engine? (crs:SR-ORG:6974)

I am using Google Earth Engine and my aim is to extract pixel values of MODIS land surface temperature (MOD11A1) at my points of interest with the best accuracy. MOD11A1 data has a pixel size of about ...
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1answer
26 views

QGIS different scale levels in rule-based styling - in one rule

I have a layer with 4 roadclasses. For this layer I created a rule based symbolization, with 4 rules. In every rule I filter another roadclass and set a different symbolization and scale for this rule....
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39 views

Raster merge in QGIS deletes scale

I try to merge 2 raster tiffs in QGIS 3.10 (Raster-Miscellaneuous-Merge). The merge is executed but the resulting map is just black, the scale is set to 0, i.e. all the information of the rasters is ...
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2answers
142 views

Printing to scale in QGIS

I want to print a map to scale on 11x17 paper. I understand you can change the scale bar to 'numeric' in print composer, and then set the scale under properties for the map. What I want to know is ...
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3answers
236 views

Export raster to PNG in 1:1 scale from QGIS?

The raster I have is 1m LiDAR data that's been patched and properly color corrected. The resolution of it should already be 1m/pixel. The coordinate system is properly set, the measure tool measures ...
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1answer
40 views

Is climate a small-scale or large-scale process? [closed]

This might sound like a stupid question but it bothers me anyway: We distinguish small-scale maps like world-maps and large-scale maps like a map of my local neighborhood. So far, so clear. However, ...
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0answers
72 views

How to have the same scale for two maps? [closed]

I'm using QGIS 2.8.1. I have one raster map with rainfall data with 1:3 scale when zoomed to layer. There's another vector map with points which in scale 1:221,691 when zoomed to layer. Both are ...
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2answers
149 views

Access QGIS rendering map context within QGIS Python function

I maintain the maps for my local Nordic ski trails. Each winter during the 'Tour de Soup' skiers travel from one soup station to another with the aid of a special event map. Because the map is ...
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107 views

QGIS 3.4 Layout manager, attribute table, scale of map

I am trying to produce maps faster than I currently do. I was thinking to use the "show only features visible within a map" option. I already use it for the coordinates table and I am trying to add ...
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1answer
280 views

Getting current map scale in PyQGIS

I'm trying to get the current map scale in PyQGIS, running outside QGIS, with: project = QgsProject.instance() root = project.layerTreeRoot() canvas = QgsMapCanvas() bridge = ...
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0answers
54 views

Different distance when using “Measure Line” tool and manually with scale in QGIS 3

Using QGIS's "Measure Line" tool I get a distance of 1.22km between two points. But if I use the scale indicated at the bottom of the screen, 1:50000, and measure with a ruler, the distance is 2.5km (...
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1answer
57 views

How to count pixels in patches of the Global Surface Water Layer (JRC)

I'm using the GlobalSurfaceWater-Dataset in GEE for creating a mask layer. The mask I do need should only contain water areas bigger than a certain threshold, so I need to get an information on the ...
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1answer
96 views

QGIS 3.4.12 print composer, cm distance

In print composer, I would like to syncronize the scale of the map with the Grid scale. For example, in print composer I am making a map in 1/1000 scale, so I go to grid,and insert "map units" x=100 y=...
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142 views

Understanding scale of Google Maps

I have found that the map section shown on one viewing is not the same as shown on a second viewing. The same designated scale produces different dimensions in the second viewing and places that are ...
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1answer
31 views

At what scale does the senitel 2a make the image? [closed]

I have to show scale in my reports, so I need to know. Please bother to tell me.
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0answers
108 views

Mean reducer changes scale in Google Earth Engine?

I am working with NOAA CFSV2 data trying to get an Image that is a one-year average of an ImageCollection. However, in the process the scale of an image changes: var uv = ee.ImageCollection('NOAA/...
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1answer
209 views

Difficulty with Scaled Visibility for Labels in QGIS 3.4.9

I am having great fun getting to grips with QGIS (fantastic). I have set myself a "project" to try to learn the techniques. This project refers to 2 Layers (geographic areas for Telephone Exchanges ...
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0answers
35 views

Log Scale Contouring in ArcMap?

I have a shapefile of concentration values, they range from 0 7000. I want to either contour or display these in log scale (0.1, 1, 10, 100 and 1000) what is the best way of doing this? I have about ...
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1answer
100 views

Dividing country into maps of scale 1:25000 (metres)?

I want to divide a country into a grid of maps that will be of 1:25000 scale. I am not sure how to approach this. Create fishnet seems like a good ending point. I have some old maps of the given scale....
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1answer
64 views

Keep the same image scale after mosaicking

I am trying to keep the same original image scale after creating a mosaic with the same images. But when I try to add in a map this image I can´t configure the visualized parameters. The problem is ...
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1answer
65 views

Converting stream definition threshold to extract drainage network to metric scale?

I extracted two drainage networks from a DEM of 30 meters resolution with two stream definition thresholds: 1000 pixels and 500 pixels. Can you tell me what this thresholds represent in terms of ...
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1answer
50 views

Locating date, scale, and coordinate system of shapefile in ArcMap?

I am trying to locate the date, scale, and coordinate system/projection of a shapefile in ArcMap but when I right click on the file in the table of contents and go to properties, I don't see the date ...
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1answer
118 views

Increase max zoom for large scale raster with GeoServer

I'm serving a large scale raster (warehouse map) with GeoServer. I consume the WMS in a Leaflet web client and coordinates are projected according to EPSG:3857. But it seems that maximum zoom is ...
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0answers
89 views

Scaling WGS84 coordinates?

I know this is a weird question, but I would like to know if it is possible to construct a proj4 string so that I can use proj4 to convert from WGS84 to a "scaled" WGS84 system. For example with a ...
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1answer
268 views

Scale of shape in a Print Layout

I am making an atlas with a fixed scale, and want to include circles with a fixed radius (in scaled kilometers) about the center point in the atlas (see image below). I was able to do this by ...
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0answers
32 views

Creating Scale field based on polyline length (ArcMap)(Python)

I'm playing around with data driven pages, and have a polyline feature class that I'm using as my index. Now, because the lines are all of variable lengths I can't just use the default settings as ...

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