Google Maps is a web mapping service application and technology provided by Google free (for non-commercial use),

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37
votes
5answers
8k views

Why is the 'straight line' path across continent so curved?

This is the result of mapping the straight line path from a point in US to Poland using Distance Measurement Tool. Also, planes from Asia to US would travel almost over North Pole. Why is the path ...
10
votes
4answers
714 views

Suggestions for simple mapping platform for alumni web site

I'm working on a proof of concept alumni site with a WordPress backend. I want to have a very simple map that shows where alumni are living. I'm thinking something like the Bing API or a simple open ...
38
votes
3answers
21k views

EPSG 3857 or 4326 for GoogleMaps, OpenStreetMap and Leaflet

The discussion at What is the difference between WGS84 and EPSG4326? shows that 4326 is just the EPSG identifier of WGS84.. Wikipedia entries for Google Maps and OpenStreetMap shows that they both ...
28
votes
8answers
45k 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
16
votes
5answers
9k views

Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { ...
11
votes
2answers
8k views

What is the difference between EPSG:900913 and EPSG:3857?

I'm using the QGIS google layers plugin to digitize a parcel as a shapefile. Later I want to import it to PostGIS. I know that google maps use a special 'google mercator' projection. What is the ...
5
votes
1answer
9k views

Create drive time polygon around a map point

I'd like to create a 30 min drive time polygon around 400 separate points I have plotted to google maps. I have discovered http://www.freemaptools.com/how-far-can-i-travel.htm but this seems to freak ...
26
votes
3answers
32k views

How to add Basemaps from Google or Bing in QGIS?

Like ArcGIS Desktop has the option of using basemaps from ArcGIS online, does QGIS have any such options?
10
votes
9answers
14k views

Consuming Google Maps as background map through ArcGIS Server?

I am doing a (non commercial) project where the client doesn't have the budget for purchasing map data like that provided by TeleAtlas. They only need map data for a background map, and they'd like ...
5
votes
4answers
6k views

Can you make a travel region polygon with with Google Maps API?

I am working on a local design project and need to determine if someone is local to my area to allow them to participate. Local, as defined by the group, means that the person is within 2 hr driving ...
4
votes
2answers
950 views

Openlayers - Vector layer polygon doesn't move in-synch with Google V3 baselayers

When a polygon is drawn on the map and the map is dragged, the position of the polygon relative to the GM V3 base changes. function init() { var map = new OpenLayers.Map('map'); var gsat = ...
4
votes
2answers
4k views

How to display a PostGIS table on Google maps?

I am attempting to take a shape file and display it on a map: I can do something like this: SELECT ST_AsText((ST_Dump(the_geom)).geom) as the_geom FROM shapes; But the problem is I still have to ...
36
votes
3answers
12k views

What is the current Web Mercator projection code?

The web mercator projection, popularised by Google Maps, seems to be given a new EPSG code every couple of years. EPSG:900913 (Google in calculator text) was an unofficial code EPSG:3785 - is the ...
38
votes
4answers
6k views

Why has Web Mercator (auxiliary sphere) become the web map standard?

I understand what the difference is between the Web Mercator projection and Web Mercator Auxiliary Sphere (WMAS). I also understand that both Google and Esri have adopted this projection as their ...
13
votes
4answers
3k views

Geocoding API Comparison

Is there a good updated source for comparing existing Geocoding APIs (i.e. Google, Mapquest) and their features? I'm really interested in their language support as well. For example, Google has ...
12
votes
5answers
1k views

Quality of free geodata compared to commercial sources

What are the sources of excellent geo-location data as possessed by Google Maps ? I am wondering that, even with large amount of volunteer work involved, why is OSM data not comparable to theirs in ...
4
votes
2answers
8k views

Calculate bearing between two decimal GPS coordinates

I'm building a virtual tour application that uses custom panoramas in conjunction with Google's StreetView service. With StreetView, you can have 1 to n links at each particular location to move to, ...
10
votes
9answers
7k views

Algorithm for finding irrregular polygon centroid (label point)

I need to find a centroid (or label point) for irregularly shaped polygons in Google Maps. I'm showing InfoWindows for parcels and need a place to anchor the the InfoWindow that is guaranteed to be on ...
8
votes
5answers
978 views

Buffers of public transportation transit times

I'd like to be able to create buffers/zones/rings of transit times using Denver's public transportation system. For an example of what I'm talking about, check out triptropnyc.com - I don't need it ...
6
votes
4answers
2k views

Point in polygon algorithm for multiple polygons

I've a Google map with bunch of polygons on it. Here is a problem I'm interested in: Given a lat,lng point, what's the best way to determine all the polygons that this point lies in? The obvious way ...
9
votes
1answer
6k views

Which is the correct projection in ArcGIS for EPSG:3857/900913?

I want to publish a mapservice in ArcGIS server, which will be overlayed on Google Maps or Bing Maps. For this, the Map Service needs to be in EPSG:3857/900913. The Google Maps projection is supposed ...
8
votes
4answers
5k views

Geocode address once in google maps, save in database, read geocoded result from there on

Is it possible to geocode an address, save the result in a database, then read that result from there on? I'm using a Google map that is geocoding hundreds of addresses which obviously hit the ...
5
votes
3answers
2k views

Does a national(USA) interstate rest stop/rest area dataset exist?

And I don't care about format--worry about that later! I found some maps in Google maps, usually per state. I also have one map made my someone else, that no longer appears in the Google Maps search ...
4
votes
1answer
8k views

How to highlight the area in google map on mouse hover

I want to implement a feature in my app (gmap powered) to highlight the area on mouse over. Much like the functionality in wikimapia. Check out the pic or url But i could't find any info on how ...
6
votes
1answer
1k views

What causes these shiny artifacts in Google Maps imagery?

Do you know what causes artifacts like this one: Source: ...
4
votes
1answer
156 views

How do you define rail network branch geocodes

As per the attached document I'm trying to define a rail network by providing geocodes for each rail stop, how would I define a 'stop' as a junction for a branch in the network without having to ...
3
votes
2answers
1k views

Openlayers using Google Maps as base layer: possible to zoom out farther than max extent?

See attached picture. This is how it is when the page loads. I'm currently using map.zoomToMaxExtent(); Everything is working pretty well but I'd like to zoom out more/see the whole world using ...
3
votes
1answer
339 views

What is the best API to use GeoTools or uDig (for the context of my application)?

I am trying to develop a java application that displays : Google maps, Openstreetmap and Bing Map Data. So which is the best SDK to use in this contet Geotools or uDig ?
3
votes
1answer
288 views

How to place markers on the outline of a circle in google maps?

I have the center of a circle and it's radius and I need to place variable amount of markers on the outline/stroke of the circle. The distance between this markers should kept same, so if I have 8 ...
2
votes
4answers
7k views

How to use Google Maps V3 Geocode with Openlayers

How to use Google Maps V3 Geocode with Openlayers. Below is my code but the function does not execute when I try to integrate it with Openlayers. This works with my original google v3 file. Below is 2 ...
0
votes
1answer
50 views

How to identify in googlemaps with below data [duplicate]

How to draw polygon in google maps with below point data?It should be plot in India Andhrapadesh startpoint endpoint startpoin xpos , Ypos endpoint xpos,ypos _0 _2 713.955, ...
0
votes
2answers
3k views

Where is Google Maps extension for ArcGIS?

I need to import Google Maps into ArcGIS for Desktop and apparently I need to activate a Google Maps extension. I'm working on ArcGIS 10.0 and there are no such extension. Do I have to install a new ...
16
votes
8answers
59k views

How to avoid Google map geocode limit?

I'm creating a custom google map that has 125 markers plotted via a cms. When loading the map I get this message: Geocode was not successful for the following reason: OVER_QUERY_LIMIT I'm pretty ...
23
votes
5answers
72k views

Display a local file in Google Maps

How can I get a KML/KMZ file to display on Google Maps without a public facing web server?
19
votes
6answers
12k views

What's next if our KML is too big/complex for the Google Maps API?

Our web app includes simple mapping capabilities (currently just markers and KML overlays on an embedded Google Map). This works pretty well; the only real limitation we face is KML overlays that go ...
15
votes
3answers
1k views

What is the wire format for Google's new vector map tiles?

Google recently released new vector cartography for their mobile maps. I'm curious if anyone here has any insight into the wire format they use for transmission? I've experimented with a few formats ...
8
votes
4answers
1k views

How to Geocode a City

First, a little disclaimer. I know that I can just call one of any number of geocoding APIs to perform this for me. This is more of a curiosity than anything else. With that aside, how does someone ...
9
votes
4answers
2k views

What is a “mashup”?

GIS users mix spatial data layers from an early age of GI science. What is new in the concept of "mashup"? Is it something really new, or only a trendy word?
7
votes
1answer
3k views

Output polygon data from postGIS and read it on Google Maps API

So, I have a group of polygons stored in PostGIS. I'm trying to build a web application with Google Base maps (using Google Maps API). Now, How do i output the polygons in the right format so that ...
6
votes
4answers
3k views

How to scrape data from a google map (in flash)?

I've contacted the author of this NYC homicide map from the NY Times several times to see if he could send me a spreadsheet of information the data is based off of, but I have not had any response ...
8
votes
4answers
1k views

Performance of google map tile creation processes

I know that question is rather vague but please bear w/me. I'm trying to get an idea of what sort of product performance - specifically timing - people have seen for various methodologies they have ...
6
votes
2answers
3k views

Generate a kml file from Google results

Is it possible to generate a kml file of searched items in Google Maps. For example: Search for highschools in Virginia Return the results as a kml file with the schoolname address and location
4
votes
1answer
4k views

Transforming EPSG:3857 to EPSG:4326

I am new to gdal and have a simple question. I want to transform an image from OpenStreetMap projection to Nasa Blue Marble projection. What I understand is that OpenStreetMap projection is EPSG:3857 ...
4
votes
3answers
5k views

Using the Proj4js library to convert from Google Maps to projected values

I'm using the proj4s javascript library (based on advice from this question I asked previously) to convert lat/long values on my webpage. This page receives the lat/long values from google maps and ...
2
votes
3answers
4k views

Which CRS to use for Google Maps?

I am trying to map a Shapefile (download) onto a Google Map using the Javascript API. The Shapefile describes the boundaries of NYC School Districts. The file's projection was Lambert Conformal ...
12
votes
8answers
5k views

What methods are there to produce map tiles for google maps?

newbie to stack exchange here. I'm currently using the automatic tile cutter found here to make the standard 256x256 tiles required to make a custom map type for my map. The map tile cutter script ...
8
votes
1answer
5k views

Using Drop Markers and MarkerClusterer together?

I want to create a rather visually appealing representation of time-series data (Costco Store Locations w/ opening dates). My idea was to plot them on a map, in time-series, but it seems that the ...
7
votes
5answers
10k views

How to Geocode 300,000 addresses on the fly?

I have a database which has 300,000 address, which are to be shown on map. I know if I geo-code all the address it will be too expensive for me. So I was wondering if it is possible to geo-code the ...
5
votes
2answers
5k views

Coordinate system and projection for georeferencing Google Maps image in ArcGIS Desktop?

I have saved Google Maps image (not Google Earth) of area at latlon(17.692437,83.218689) by some method in jpeg format. It is an exact snapshot of the Google Maps. Now I need to geo-reference it to ...
5
votes
4answers
1k views

What is a best practice way to display/feed US census/tiger data into Google Maps API?

Let's say I want to display age, income, etc based on census block groups on Google maps. What is the best practice or recommended way to do so and also to allow to do simple queries?