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

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48
votes
12answers
93k views

What ratio scales do Google Maps zoom levels correspond to?

Can anyone provide me with a link (or some details) on the actual ratio to "zoom level" figures for Google Maps? e.g. Google Maps Level 13 = 1:20000
13
votes
3answers
4k views

Changing symbology at different scales in ArcMap?

I am using ArcMap 10 and I want to display my village parcel symbology differently at given scales. I have one idea to copy and paste same layer. But my question is that in a single layer, is it ...
12
votes
1answer
463 views

Scale in printed map (mxd) is different in code to manual printing

This question is related in part to a previous question I have asked. I have tried printing an A3 mxd with the Print Active View code as published by ESRI and have changed only one line of code and ...
11
votes
4answers
487 views

How to generalize coastlines?

I have a large set of data points that essentially represent the coastline of the world. I don't know the exact resolution but I'd say it's in the neighbourhood of 5-10m. Imagine a set of points ...
10
votes
2answers
1k views

Surface distance on DEM between two coordinates

Given two coordinates on a digital elevation model (DEM), how do I compute the actual distance traveled between the two locations, assuming a straight line route? How will changing the resolution of ...
9
votes
0answers
172 views

How do ESRI and QGIS calculate scale values of geographic projections? [closed]

Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections? The only thing I've noticed is that QGIS is changing scales when you pan ...
8
votes
6answers
1k views

Maps zoomed around specific locations (magnifying glass effect)

How do I create a static map where the scale varies based on location? Example: to drive from a specific location X in Albuquerque to a specific location Y in Chicago, I want to "zoom" around X and ...
8
votes
5answers
5k views

What are standard scales, or zoom levels, for map applications?

I am working on an ArcEngine program that is restricted to a set of scales. It currently has: 1:187.5 1:375 1:750 1:1500 1:3000 1:6000 1:12000 1:24000 1:50000 1:100000 I don't think there's ...
7
votes
2answers
14k views

OpenLayers: Use scales instead of resolutions

Venturing around in the OpenLayers source code, it seems like everything related to zoom-levels is done using resolutions. Fair enough since this related directly to screen space. I would like ...
7
votes
2answers
3k views

How to create a vertical scale bar in ArcMap?

Wondering if anyone out there knows how to create a vertical scale bar in ArcMap? With text I can adjust the angle. Is this possible with a scale bar as well?
7
votes
3answers
2k views

Using GIS for Interactive Floor Plan

GIS is brand new to me, but I've spent a couple of days researching so that I can at least ask somewhat intelligent questions. I've decided to use QGIS I need to do an interactive floor plan on the ...
7
votes
1answer
2k views

How to automatically generate useful scales for data driven pages in ArcGIS desktop

I have been tasked with creating several hundred maps of properties that intersect a long pipeline. The maps will zoom to the part of the property which shows the intersection. The lengths of ...
7
votes
3answers
393 views

How to handle display of nested polygons (census, county/state, etc) for a given map extent

My question is how best to decide which layer (from a set of nested, aggregated census polygons) to display for any given map extent in an online map. Australia's census boundaries are built from ...
7
votes
2answers
331 views

What does map scale refer to in map making / field survey metadata?

If I have, say, a printed map at the scale of 1:20000 and the legend says that it was mapped at a scale of 1:10000 does this simply mean, that the surveyors/cartographers made drafts & sketches or ...
6
votes
1answer
331 views

How to fix distortions in rendered OpenStreetMap maps?

I use OpenStreetMap in order to generate maps and add some cool stuff in it. Actually I have good results but I seem to have a problem with reporting a good image ratio when I create my generated ...
6
votes
2answers
1k views

Scale and Z factor have no effect on hillshade analysis in QGIS

I used an SRTM DEM to create a hillshade in QGIS 2.2.0. However, the resultant hillshade seems to be vertically exaggerated. Also, changing the settings for scale and z-factor does not have any effect ...
6
votes
1answer
4k views

How to calculate the bounding box by a given center and scale in Android?

Given these conditions: a scale like 1:50000 the center of the viewport is 100°E, 20°N the size of the viewport is 400x600 How can I calculate the bounding box of the viewport? Update after ...
5
votes
3answers
288 views

How to know if shapefile is georeferenced?

I have a shapefile which is located in province in indonesia. it contains many sub-province if i removed sub regions inside a shapefile, and it leaves a small region, and my question is that small ...
5
votes
2answers
986 views

What does Scale mean in the reference of Desktop GIS or WebGIS?

I'm having trouble understanding the meaning of the concept of scale when it comes to maps on screen, i.e. either in a Desktop GIS or in a WebMap. When it comes to paper maps, the idea is very clear. ...
5
votes
1answer
722 views

Georeferencing a jpeg in QGIS but the scale is way off

I've gone through the really helpful walk-through(s) of how to georeference a jpeg in order to make it a layer, but after inputting the coordinates (either by typing in actual coordinates or clicking ...
5
votes
2answers
1k views

Custom scalebar units in ArcMap?

Is it possible to create a scalebar in ArcMap that shows distances in custom units? I understand how to do this manually, but it would be great if I could define a custom unit of measurement (let's ...
5
votes
2answers
675 views

Can you print cross-hatch area fills like they appear on screen?

I'm trying to use a cross-hatch symbol on polygons in QGIS. When displayed on screen, they look just fine - both in the map and in the composer. The problem is when they are rendered to an image ...
4
votes
1answer
758 views

Clarification of Map Scale

I need some clarification. I have a map the is set to the scale of 1:6000. In Settings>Project Properties, under the General tab I have the Layer Units set to feet. Therfore I assume that means the ...
4
votes
2answers
10k views

Arcmap 10 feature with undefined coordinate system projects incorrectly when projecton is defined

I'm fairly new to GIS, and am slowly feeling my way through ArcMap 10. I have run across a problem defining the Geographic Coordinate System and projection for a feature (the feature currently has an ...
4
votes
2answers
64 views

Map scale based on altitude

I'm either missing something or failing at some basic math here, but is it possible to calculate the map resolution (map units/pixel) based on altitude (from sea level)? I have center coordinates and ...
4
votes
4answers
130 views

How do I create a map that is not to scale in QGIS?

I want to make a map that isn't to scale and I'm so used to being pedantic about CRS and scale that I don't know where to start. The map that I need to make is a simple guide for people to get to a ...
4
votes
2answers
146 views

“GIS” Mapping on Monument - Scaling

I have a Baroque tombstone for which I have to map the damage phenoma. Normally one can use a vector drawing programm but one has always two boundaries between the different polygons. Questions: Is it ...
4
votes
2answers
134 views

Measuring scale for small scale maps

A cartography question: you open an atlas and usually at the beginning of it there are some world maps showing various thematics. Let's say the world map uses Robinson projection and it says it has a ...
4
votes
1answer
371 views

how does arcmap calculate scalebar inside a WGS84 layout?

ArcMap lets you put a scalebar inside a layout referncing a WGS84 data frame. How is the scale calculated? Is it a "mean" scale? And, in case it's right, what "mean" scale could mean?
4
votes
1answer
1k views

Changing the scale (generalisation) in ArcGIS 10

I have 2 polygon layers, accordingly 1:10 000 and 1:500 000. I want to generalize the first layer from 1:10 000 to 1:500 000. I tried using Simplify polygon tool, and since these scales relate to ...
4
votes
1answer
402 views

Why do base and overlay only match at scale 1:1000 and 1:2000?

We are using GEOSERVER 2.1.4 to overlay WMS on GoogleMaps V3 with Openlayers . The problem we have is at different zoom levels the scale of the WMS overlay is different from the scale of the base ...
4
votes
1answer
2k views

How can I change the display name of the “Scale” control?

Here is the thing. I added the Scale control to my web and is displayed in a div at the bottom. I need to translate the "Scale" text to other language but I can't find how to do it. I searched in the ...
4
votes
1answer
143 views

Is there a way to change the scale bar interval and other settings on individual Data-Driven Pages?

Sometimes I'll have a MXD set up as a mapbook using Data Driven Pages, but I'd like to display certain pages at a different scale than others in the same mapbook. I can do that using the Data Driven ...
4
votes
1answer
1k views

Finding suitable font size for map scale in ArcGIS Desktop?

Is there a website that suggests suitable font sizes for each scale level in the layout? I am currently using ArcGIS 9.3 but pretty soon will upgrade to 10.
4
votes
1answer
1k views

Dimensional analysis/conversion problem: Map scale to image resolution (dpi)

Given a map scale of 1:17,200 and a raster whose cell size is 6 inches, what resolution (dots per inch) should I choose when exporting the map to an image in order to maintain the raster's native ...
4
votes
3answers
120 views

Layer Extent NOT Set When Bringing In ArcGIS Server map service?

I published a mapping service on ArcGIS Server 10.3, set the layer to 'Don't show layer when zoomed' 'in beyond' to 1:577,791, prior to publishing. When I bring in the mapping service into ArcMap, ...
4
votes
1answer
876 views

How to use scale -rule based renderer in QGIS?

I wish to render a shapefile of builindings such that at scales below 1:5000, they have a border, and above 1:5000, they do not have a border. For this, I went into layer properties, selected ...
4
votes
2answers
281 views

The scale in Qgis is not setting to feet

I am working in QGIS 2.4. I have changed the CRS of all the layers and in the project properties to EPSG:102739 - NAD_1983_StatePlane_Texas_Central_FIPS_4203_Feet. I am in print composer trying to ...
4
votes
0answers
3k views

How to use Scale tool when Georeferencing Raster in ArcMap?

I'm georeferencing a bunch of maps in ArcMap 10.0. The Shift and Rotate commands are pretty easy to use, no problems there. But whenever I use the Scale command, the image completely changes ...
3
votes
1answer
1k views

How to get correct scale values?

The scale of my map is wrong, no matter what coordinate system I use in my project. The map and all objects show the correct coordinates but the scale of the map shows nonsense and the measurement ...
3
votes
1answer
583 views

What are some examples of model-based upscaling of raster data?

Remotely-sensed raster data may be too fine-grained for many purposes. A typical approach to coarsen the grain is to upscale by reducing the resolution. If the data are continuous (e.g elevation, ...
3
votes
2answers
5k views

Why does QGIS scalebar show a wrong scale?

I'm using QGIS 1.7.1 and have added a scalebar. The scalebar usually displays in degrees, unless I switch the map's projection to meters, in which case the units are display in cm. This is not ...
3
votes
1answer
762 views

QGIS Shapefiles have the same CRS but dont line up. (Census Tiger Data & State Data)

I have the Census Tiger data for Oregon from http://www.census.gov/geo/maps-data/data/tiger-data.html Then the bottom one of 2010 Census Population & Housing Unit Counts — Blocks. The shp ...
3
votes
1answer
3k views

Dynamic scale bar, coordinates and grid for map frame in Mapinfo map layout

I am looking for a dynamic scale bar and coordinates (grid) for map frame in the map layout of Mapinfo. To make it clear I am talking about separate scale bar in layout which is not part of map ...
3
votes
2answers
667 views

Silverlight Map with ESRI Imagery

I have a map service which is using data from a local repository, viewed using the ESRI Silverlight API. I am dynamically adding a tiled map service for imagery from ESRI. The map service can be ...
3
votes
1answer
102 views

How to automatically assign current map scale to a shape created in QGIS?

In QGIS, would it be possible to automatically assign the current map scale to a feature created during an edit session and save it into a field in the attribute table? I have a series of OS maps of ...
3
votes
1answer
87 views

Equatorial Scale

I have seen Equatorial Scale written along with the RF on the World Map in many Atlases, for eg., "Equatorial Scale 1:95 000 000". What does this Equatorial Scale mean and what is the significance of ...
3
votes
1answer
5k views

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

I have an image and detect two points in the image. I want to calculate the distance between these two points. I'm using Google map and Bing map. I have x,y pixel values for both two points zoom ...
3
votes
2answers
2k views

How do I know the vertical/horizontal units of my DEM? I'm creating a slope using gdaldem

I'm using gdaldem to create a slope map. I can apply a scale. The default is 1. The notes say: Ratio of vertical units to horizontal. If horizontal unit of source DEM is degrees (e.g WGS84 ...
3
votes
2answers
2k views

Figuring out map scale when you know the spatial resolution of a Satellite Image?

I'm interested in figuring out how map scale and satellite pixel size (spatial resolution) are related. For example the TM or ETM+ has roughly 30m ground resolution, then, what could be the finest ...