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74 votes

What ratio scales do Google Maps zoom levels correspond to?

I found this response - written by a Google employee - this would probably be the most accurate one: This won't be accurate, because the resolution of a map with the mercator projection (like Google ...
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22 votes
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Different layer styles at different scales in QGIS?

Yes, it is possible. What you need is rule-based Styling with a scale rule as shown in the image (sorry for german layout) It looks like this when you zoom in and out : keep in mind, that when you ...
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  • 3,881
20 votes

On a map of the globe that is 1920x1080px, how big would each pixel be?

Assuming you are talking about a map of the world in Mercator Projection, Something like this: Then, You should know that not all pixels will represent the same area. There is a large amount of ...
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15 votes
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Putting scale bar labels below scale bar in QGIS?

I don't think there's an option yet which allows you to put the units below the scalebar. An alternative could be to: Modify your current scalebar and set its Font colour to match the background ...
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  • 72.5k
13 votes
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How to get current scale of a Leaflet map?

You can get the current zoom level using getZoom(). Assuming that you're using the tile layer system as used by Google Maps, Bing, Open Street Map and Esri, you can use that to infer the scale - see ...
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13 votes
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Is it possible to set different scale dependent visibility for one layer classifications?

You need to use Rule based style to set the scale for primary, secondary and tertiary network, as you can see below (but with different data): You can double-click each styled label to get more ...
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  • 36.5k
10 votes
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QGIS Print composer scale problems

EPSG:3857 doesn't conserve distances so this will depend on where on the earth you are mapping - I think the scale is calculated at the Equator. The easiest fix for this is to switch to an ...
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  • 75.5k
10 votes
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What is WMTS' ScaleDenominator?

Standard linked by @user30184 (portal.opengeospatial.org/files/?artifact_id=35326) explicitly and precisely defines ScaleDenominator in section 6.1 "Tile matrix set – the geometry of the tiled ...
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  • 151
9 votes
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Locking the scale while resizing the panels in QGIS

That's what the lock icon next to the scale does.
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  • 372
8 votes

Calculate scale of a raster

Rasters don't really have a scale, they have a resolution, which in your case is 200m. You can calculate an appropriate viewing scale for a given raster resolution based on the ability to distinguish ...
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  • 53.3k
8 votes

How to change units and scale of a shapefile?

If you want to increase the size of a feature, you can use the Scale tool in ArcMap. It's an Editor tool but it's not on the toolbar by default, you'll need to add it using the Customize option for ...
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  • 12k
7 votes

Digitizing Map To Scale?

Not at all. When you have some data that was digitized at 1:100,000, it excluded smaller features, which were smaller than the Minimum Mappable Area. For example, suppose you are dealing with ...
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7 votes

Zoom map to a scale in Leaflet

First, a note about map scales. A map scale represented as a unitless factor (e.g. 1:50000) means that a map unit represents X map units (e.g. a meter in the map = 50 km in reality). This kind of ...
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  • 9,410
7 votes
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Data defined label position for more than one scale in one layer

I have to say that what you are requesting is complicated a little bit because you want the labeling to be visible at small scale clearly as well as at large scale (best fit). So, the idea here is how ...
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  • 36.5k
6 votes

How to calculate pixels per meter ratio, according to Google or Bing map zoom level?

I have written this on Android and it works. Google map tiles are 256 device independent pixels. So this first line calculates a tile size in device dependent pixels. The second calculates the number ...
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6 votes
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Geoserver SLD for min-max scale range display

Below SLD code works for scale range: <NamedLayer> <Name>grid</Name> <UserStyle> <FeatureTypeStyle> <Rule> <MinScaleDenominator>300000</...
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  • 459
6 votes
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Zoom Scale in OpenLayers 3

I have test it a bit and seems to work correct. Inspired from this var res = getResolutionFromScale(200000); alert(res); function getResolutionFromScale(scale){ var units = map.getView()....
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  • 3,498
6 votes

How to get current scale of a Leaflet map?

If you want just the label: // add a scale at at your map. var scale = L.control.scale().addTo(map); // Get the label. var metres = scale._getRoundNum(map.containerPointToLatLng([0, map.getSize().y ...
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  • 11.1k
6 votes
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Printing to Scale only works for PDF format

A PDF file has a controlled page size that can be used by the reader app (Adobe Reader or similar) to output a set page size when printed. Image files such as TIFF, PNG, BMP etc., are not a page at ...
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  • 29.2k
6 votes
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Georeferencing scale error

Because of Pseudo Mercator? Pseudo Mercator is not a proper Coordinate System to measure areas. Depending where you are on Planet Earth, there can be huge differences in area-size compared to other ...
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  • 1,165
6 votes

Scale feature in QGIS

You can use QAD Plugin which has a scale option, and you can enter a scale factor to scale your feature. If you are familiar with AutoCAD, this plugin works almost same, and it is very powerful. For ...
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  • 36.5k
6 votes
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Finding scale of map in QGIS

The solution You have defined a wrong CRS. To solve the problem: Right-click your layer, set CRS back to EPSG:4326. Now it is in the correct place: Always load a basemap in the background to check if ...
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  • 42k
5 votes

Measuring tool shows different measurements for same building in two different map documents?

The projection that you use will distort the properties of your objects. You can select your projection to preserve the shape, the area OR the distances but not all at the same time. If you want a ...
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  • 48.7k
5 votes
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Setting Scale Dependent Visibility for WMS in PyQGIS

You could try something like this (in QGIS v.2.8.1): miniScale = 'crs=EPSG:27700&dpiMode=7&featureCount=10&format=image/jpeg&layers=9&styles=&url=http://192.000.0.00:0000/...
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5 votes

Calculate scale of a raster

according to our good friend "Tobler," whom stated in order to calculate map scale, multiply the raster resolution (which should be in meters) by 2 multiplied by 1000. So in my above question my ...
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  • 121
5 votes
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When does a local system introduce errors in a map due to the earth's curvature?

This answer will derive a simple, useful rule of thumb. Its analysis suggests that within any region of diameter a, the relative error when using a suitably well-chosen map projection to measure ...
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  • 67.8k
5 votes

stack 10 modis ndvi geotiffs and scale them by 0.0001

In Windows (run OSGeo4W shell): Scaling: for %i in (*.tif) DO gdal_translate -scale -2000 10000 -0.2 1 %i outputs\%i You might find recalculating instead better: for %i in (*.tif) DO gdal_calc.bat ...
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5 votes

Map scale based on altitude

Map resolution is in no way related to the altitude, ESRI defines resolution as The detail with which a map depicts the location and shape of geographic features. The larger the map scale, the ...
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5 votes
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How to check my EPSG and units in R when it is not defined in proj4string?

The proj string does not contain an EPSG code. You can use EPSG:4269 or +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs. Some softwares try to guess the EPSG code from the string, and ...
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  • 75.2k
5 votes

QGIS Print composer scale problems

Generally speaking the UTM grids are a good place to start if measurements or scales are involved. In your particular case (Switzerland) this would be UTM 32N and I'd recommend the ED50 (European ...
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  • 702

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