Hello! Wht's the equation to calculate distance between two locations using latitude and longitude?plz help me

Question

i m a beginner to learn GPS . Please answer as soon as possible! Thank you!!

Answer 1

I will give you the approach.

Basically it is solving in Spherical trigonometry.  Spherical trigonometry deals with spherical triangles, which are formed by three arcs of three great circles. Arc lengths are in radians.

2 points A & B, their lat/ long are made into one arc. Another formed by the segment of longitude from pole to point A (the line is long of A, hence the arc length is [pi/2 - lat. A] and the third similarly for B, [pi/2 - lat. B]. One formula is the ratios of

sin(arc)/sin(opposite angle) are mutually equal. There are some more formulae like Napier's rule, that one can get in any mathematical tables books. Once the arc lengths are obtained (in radians) these are converted to degrees.

Each (arc)degree = 60 nautical miles (each of 6080')

=69 statute miles (each 5280')

=111 km .

It implies that 1minute arc length is 1 nautical mile.

Another formula that is quite handy is that of great circle that cuts equator (reference for the whole spherical coordinate system), at inclination i on long. L

tan (lat) = tan (i) sin(long-L)

which gives the lat/long of a point on this great circle.

People follow their own methods; standard procedure in route planning for air-routes is best. S/W packages are available.

Answer 2

Equations are:

Tan (Course) = Departure / D'Lat.

where Departure = Difference in longitude x Cos ( Mean Latitude)

where mean latitude = (arrival latitude + departure latitude) /2

Cos (Course) = Departure / Distance.

Sin (Course) = D'Lat/ Distance.

D'Lat = Difference in arrival and departure latitude.