geolocation

Latitude Longitude Database

Where can one obtain an open source or licensable database of latitudes and longitudes for various cities? ...

What pre-existing services exist for calculating distance between two addresses?

I'd like to implement a way to display a list of stored addresses sorted by proximity to a given address. Addresses in the list will be stored in a database table. Separate parts have separate fields (we have fields for postal code, city name, etc.) so it is not just a giant varchar. These are user-entered and due to the nature of the...

Geolocated version control?

Much like it's possible to geotag pictures, I wonder if there is a way to automatically geolocate the code associated with a commit - or any changes - in a version control system like SVN? I couldn't find any information about this and I don't know if for example SVN stores the IP address used by the committers, which in most situation...

How do I limit which countries can view my website ( PHP )

In there an easy way to do this in PHP. I want to make sure that only web requests from certain countries are able to access my website. Any ideas? ...

Java, convert lat/lon to UTM

Does anyone know of a way, in Java, to convert an earth surface position from lat, lon to UTM (say in WGS84)? I'm currently looking at Geotools but unfortunately the solution is not obvious. ...

Geolocation web site for pictures

Not being a web developer myself, but having idea for a cool web site, how does one create such a web site? [The web site idea] I need to build a simple social web site where people can upload pictures, comment on the picture, and most importantly, log the actual location of what is in the picture with a google map view of it. Upon en...

Are there any better geolocation databases / technologies / services or has anyone done any work with improving the accuracy of existing systems?

I am working on integrating geolocation services into a website and the best source of data I've found so far is MaxMind's GeoIP API with GeoLite City data. Even this data seems to often be questionable though. For example, I am located in downtown Palo Alto, but it locates my IP as being in Portola Valley, which is about 7 miles away....

Testing IP based geolocation

We are implementing an IP based geolocation service, and we need to find some IP's from various markets (LA, NY etc) to fully test the service. Does anybody know of a directory where we could find what IP ranges are used where? EDIT: We have already implemented the system, it uses a 3rd party DB and a webservice. We just want some IP's...

How does a website know what city I'm in?

Many web sites know where I'm from. For example, visiting Yelp shows me restaurant listings from the nearest metropolitan area and searching for "maps" on Live Search shows me a map of my current city. My best guess is sites do this by using a large database mapping the user's IP address to city name. If this is true, where's the best...

Geolocation API on the iPhone

Does anyone know whether the iPhone supports or will soon support the W3C Geolocation specification? I'm looking to build an app for mobile users, but rather than spend the time developing apps for every different platform (iPhone, Android, etc...), I'd much prefer to create a web app that makes use of the W3C Standard. ...

Simple Geographic Data Sources for a Web App

For a web app I'm working on, I need to know the lat/lon of about 300 US cities. I also need to know the lat/lon for every US zip code. Does anyone know of a free source to get this information? ...

How do I use a state specific proxy?

I need to hit a website through a state specific IP Address. Any suggestions on how to do this? ...

Redirect depending on the Country?

We basically have 2 sites ( Java /JSP / Apache Webserver) : something.ca & something.com The .ca is canadian content, and the .com is american content. We need users to be redirected based on the ip addreess. We want US users to get the .com site and Canadian users get the .ca site. What is the best way to do this (at a webserver le...

Is there a formula to convert from Thomas Bros Map page & grid to a latitude/longitude?

I'm working on a project that contains Thomas Brothers Map page and grid numbers. Is there a way to programatically convert from this map page to a latitude & longitude? An Example would be for the intersection of the US101 & I405 freeways. ThomasBrothers: 561-3G (page-grid) ...

Is there an easy way to plot Polyline Area, i.e. service coverage area, and also check to see if visitor's address lies within that area using Google Maps API and PHP?

Hello. I am the owner of a business that is building a new website application. My partner is the programmer who is doing the development and neither one of us has any real in-depth experience with Google Map API or it's polyline/polygon area capabilities. We need an easy way to capture inputs within our user admin area where our locati...

Know a good IP address Geolocation Service?

I'd like to get your impressions on any ip geolocation (as in IP to location) service services you may have employed? I'm looking for something free or cheap, which shouldn't be unrealistic because I need to make a very small volume of requests. Anything with python bindings would be especially ideal. ...

Most efficient way for storing geolocations in a database.

I know postgres has a datatype for storing geographical coordinates. But I'm looking for a RDBMS agnostic solution. Currently I'm using Decimal(25,20) in MySQL. I may be using this data to lookup these locations based on a given distance from a given location later. Which would be the best approach to store this kind of data? ...

Where can I get postal codes for all countries?

I once read about an open source database for postal codes with geolocation data but now I can't remember its name. Can someone help? ...

Is there a way to get the users location without having the user install Google Gears?

I don't want to have the user install Google Gears so I can show him his guessed location. Is there a way to get the location without having to use Google Gears? I have found http://www.wipmania.com/de/blog/google-geolocation-api/ but it does not offer an example. ...

Determine the centroid of multiple points

Hello, I'm writing a mapping application that I am writing in python and I need to get the lat/lon centroid of N points. Say I have two locations a.lat = 101 a.lon = 230 b.lat = 146 b.lon = 200 Getting the center of two points is fairly easy using a euclidean formula. I would like to be able to do it for more then two points. Fund...