The ratio between distances on a map and distances in the world
11
votes
4answers
343 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
809 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 ...
7
votes
6answers
509 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 ...
7
votes
2answers
6k 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
5answers
845 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
3answers
286 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
92 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 ...
5
votes
1answer
162 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 ...
5
votes
1answer
61 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
597 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 ...
5
votes
2answers
178 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 ...
5
votes
0answers
273 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 ...
4
votes
2answers
2k 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
393 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?
4
votes
1answer
192 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
156 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
339 views
Find a suitable font size for the map scale?
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.
Thanks !
4
votes
1answer
430 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 ...
3
votes
1answer
103 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
572 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 ...
3
votes
1answer
182 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
709 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 ...
3
votes
1answer
803 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 ...
3
votes
2answers
569 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
253 views
Different coordinate system for map project and scalebar?
Is it possible to specify a coordinate reference system (CRS) for the scalebar that is different to the project CRS?
Example: my project CRS uses geographic coordinates (lat/long), the reason being ...
3
votes
1answer
119 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 ...
3
votes
1answer
50 views
Is there a way to scale to 1:1 in QGIS Cloud?
Someone knows if with QGIS cloud Pro Plan, it's possible have a scale till 1:1. I use QGIS to draw small stuff on my gis (archaeological finds, as really small pottery's sherds) and I need a scale ...
3
votes
1answer
643 views
Openlayers + WMS layer. Use scale or resolution + DPI
I have a problem with displaying map with WMS layer in Openlayers. I'm able to display it but the image of the map is not sharp especially at higher zooms.
I have a documentation from the map ...
3
votes
1answer
858 views
MapInfo Bing Aerial resolution/scale
I am using MapInfo to display some Bing aerial photos. It seems as if it is using the wrong scale of imagery - they look blurred, as if the image has been enlarged.
Is there a way to force it to use ...
3
votes
0answers
143 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
2answers
165 views
What is the unit of measurement for scale?
Maybe this is standard across mapping engines, but in MapGuide if I set the scale to 7 million I can see about half the world. At about 4 million I can see a continent. What unit of measurement ...
3
votes
1answer
727 views
Mapserver, TMS, Scales zoom levels and how to deal with all of it
I have a whole bunch of data in my db that I need to draw at different zoom levels using Mapserver. Everything uses a 4326 SRID. My (custom) client, will fetch the data using 20 TMS zoom levels and ...
2
votes
1answer
113 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 ...
2
votes
2answers
698 views
MapServer computes wrong map scales — off by factor 0.77. Or is it just me?
I've noticed in a current project that MapServer seems to get the map scale wrong, or then I'm wrong, but don't see how.
My mapfile contains the following definitions:
RESOLUTION 72 # this is the ...
2
votes
1answer
58 views
importing coordinates via a csv file does not work
I tried to manually add point data via a CSV file to an empty project in QGIS 1.8.0. The points do show up all right with the correct coordinates, but already the scale is not correct (using the ...
2
votes
1answer
109 views
How to Determine to world map size in pixel given this data?
How to Determine the world map size in pixels given this data?
Map size of a particular area say, for example:
Makati city, Philippines with bounds:
Top-Right: 121.0281, 14.56497
Bottom-Left: ...
2
votes
2answers
2k views
ArcGIS javascript API - draw circle of a specified radius in meters
I am trying to add a circle of a specified radius (let's say 200 meters) to a map. My thought is to create a SimpleMarkerSymbol object. The constructor asks for a size of the symbol in pixels, but I ...
2
votes
2answers
2k 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 ...
2
votes
1answer
555 views
I have several layers (polylines and polygons) that are of the same area but they don't overlap in ArcMap as they should, what do I do?
For my GIS project for my class, I have downloaded several vector layers from different websites (polyline of the continental divide, a boundary polygon of New Mexico, a rivers and water bodies layer ...
2
votes
1answer
46 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 ...
2
votes
1answer
196 views
How to show labels depending on the zoom scale and save it forever in one project?
I have got a problem in showing labels for a polygon layer :
When I select "Show labels" in the layer's properties, then I select that I want to use the scaling to show or not my labels and I ...
2
votes
1answer
166 views
Python script for Data Driven Pages to run a series of DDP at once?
I have a several different polygon shapefiles that I am using to create individual maps for each polygon within the shapefile.
The layout is the same for each map, the only thing that changes is the ...
2
votes
0answers
43 views
Set a user scale to use QGIS for surfaces documentation
I would like to use QGIS for the documentation of mural paintings (so I don't need georeferecing) I would like to set my own scale from a raster file (measure a know distance and use it as reference). ...
2
votes
0answers
327 views
How to calculate the scale of map tiles accurately?
In web maps, there are two coordinate: wgs84 geographic coordinate and web mercator project coordinate. The displayed scale of a world map is the value at equator, and one 256*256 pic can contain the ...
2
votes
0answers
1k views
How to zoom exactly to a desired scale in Flex?
I am using ArcGIS API for flex 2.4 with ArcGIS server 10. I am trying to write the widget where user can define the map scale (type it in text box) and it will zoom to that scale. I successfully ...
1
vote
1answer
182 views
How can the scale be projected correctly in Quantum GIS when it is imported from google earth (KML) files?
While importing KML files from google Earth to Quantum GIS, the scale is not being projected properly and the area of a particular selected feature is not being calculated in the attribute table by ...
1
vote
2answers
82 views
What is the default unit for QGIS scales and how do I set it to KM?
I want to render a specific layer only between 0-12km but have no idea how to set it in QGIS because the scales dimensions are high numbers.
My project and layers CRS is EPSG:2039
Thank you .
1
vote
1answer
315 views
What do I need to change to get scale bar units other than degrees?
Measurements done in QGIS on my project are done properly using whatever unit is set in:
Settings > Options > Map Tools > Preferred measurements units
but the scale bar decoration and scale bar in ...
1
vote
1answer
237 views
displaying scale of dyamic map service layer using ArcGIS JS API
In ArcGIS JS API, I would like to know and display the scale of a dynamic service layer by using the onExtentChange event, but the LOD argument is only valid for tile map services. Is there an ...
1
vote
1answer
650 views
Dynamic scale bar, coordinates and grid for map frame in Mapinfo map layout
I believe dynamic scale bar and coordinates (grid) for map frame in map layout are BASIC things which Mapinfo (GIS software for thousands dollars) should allow me to do. To make it clear I am talking ...
