Calculating Geographic Distance

Any geographical analysis almost invariably involves calculating distance between two points on the surface of the Earth (or two geographic coordinates). Below are four different options/formulas to calculate geographic distance. Each formula makes different assumption about the Earth’s shape and thereby has different accuracy and computational complexity.
Formula 1: Pythagorus’ distance formula
distance = ( (lat2 – [...]

A point about Latitude/Longitude

With the increasing proliferation of GIS Technology and GPS enabled devices, it is increasingly getting common for everyone to deal with latitude/longitude (lat/lon) on a daily basis. However, a simple, yet important, about lat/lon is often missed by users of GPS devices and also by the developers of mapping application. Most users and developers assume [...]

‘Save to My Map’ – A missing (hyper)link

Today, while trying to help one of my friend plan his Yellow Stone trip, I created a Google Map of one of my most memorable road trip (image below). For long, I have been thinking of creating a map of this road trip and today, finally, I got a chance and reason to do it.
Creating the map of my [...]

Garmin Forerunner (301) to Google Maps

Yesterday I did my first 10 Mile run. I was very excited about this and wanted to share with everyone. However, I couldn’t find single webservice or software that could have turned my GPS data from Garmin Forerunner 301 into a nice simple Google Map as show below.

 

Google Map showing route information of my 10 [...]

Interesting World Population Distribution Cartogram

 
Source: WorldMapper  (Link to Map)
Geographers always find innovative ways to display geographic data and at the same time amuse people. One such map technique that I always find very interesting is cartograms.  I was just checking about India’s population and came across this cartogram.
The funniest thing was that as soon as my friend saw the above map, he compared India to [...]