Explain the meaning of latitude and longitude expressed in decimals as in Google Maps.?

Latitude and longitude was expressed in degrees (example 55 44 N). After Google Maps came into existence, a new representation came up and that was the decimal representation (example 38.706089,-103.198244). Please explain what is this decimal representation? Is it the radians obtained from degrees by dividing it by 57.2958? On this website http://www.meridianworlddata.com/Distanc鈥?/a> they have calculated the distance between 2 points as



Approximate distance in miles:



sqrt(x * x + y * y)



where x = 69.1 * (lat2 - lat1)

and y = 53.0 * (lon2 - lon1)



Just wanted to know that the units of lat1, lat2, lon1, lon2 in above formula is in degrees representation or decimal representation?Explain the meaning of latitude and longitude expressed in decimals as in Google Maps.?
Decimal degrees has nothing to do with radians. In your example, 55 degrees 44 minutes = 55 + 44/60 = 55.733 degrees. Decimal degrees is not new with Google Maps, it was used for hundreds of years before that.



The link you gave doesn't work, and that distance formula is all wrong and will give wrong answers. (Unless the latitude is close to 39.9 degrees north or south, and the the latitude and longitude differences are small). Even at 38.706089 degrees north, the error is 0.32 miles out of a distance of 87 miles. But if you use the formula anyhow, the units are degrees.Explain the meaning of latitude and longitude expressed in decimals as in Google Maps.?
The ancient Babylonians thought the year was 360 days and, therefore, divided the circle into 360 degrees, one degree being the sun's right ascension. They also used fractions of one sixtieth. That is why we still, today, divide the degree into 60 minutes, each divided into 60 seconds.



On the scale of the latitudes, the nautical mile is defined as one minute of latitude or 1,852 meters.



But adding angles in degrees/minutes/seconds can be complicated. I did that, many years ago, when navigating with a sextant. That is why the current position notation for aviators and seafarers is the degree, minute and decimal of minute, although that AIP (national aviation publications) still use the second.



Using signed degrees and decimal of degrees has nothing to do with Google Maps, it has existed for a long time and as I wrote my first navigation program in the mid 1980s, I was already converting everything by that, internally in the program. It is the only way to add of subtract in a sensible way.



By convention, signed geographical position is positive on the east of Greenwich and on the north of the equator. That gives a position in the US to be positive latitude and negative longitude (west of Greenwich).



To convert minutes into fraction of degrees, you simply divide it by sixty and add it to the degrees. This is what you should do before doing mathematical operations on your position.