Вычисление азимута и расстояния между двумя точками

http://gis-lab.info/qa/great-circles.html

Python

import math
 
 #pi - is pi - 3.1415..., rad - earth sphere radius
 rad = 6372795
 
 # Points coordinates:
 llat1 = 77.1539
 llong1 = -120.398
 
 llat2 = 77.1804
 llong2 = 129.55
 
 # in radians:
 lat1 = llat1*math.pi/180.
 lat2 = llat2*math.pi/180.
 long1 = llong1*math.pi/180.
 long2 = llong2*math.pi/180.
 
 #cosinus and sinus of latitude and longitude differences
 cl1 = math.cos(lat1)
 cl2 = math.cos(lat2)
 sl1 = math.sin(lat1)
 sl2 = math.sin(lat2)
 delta = long2 - long1
 cdelta = math.cos(delta)
 sdelta = math.sin(delta)
 
 #calculating the length of a large circle
 y = math.sqrt(math.pow(cl2*sdelta,2)+math.pow(cl1*sl2-sl1*cl2*cdelta,2))
 x = sl1*sl2+cl1*cl2*cdelta
 ad = math.atan2(y,x)
 dist = ad*rad
 
 #initial azimuth calculation
 x = (cl1*sl2) - (sl1*cl2*cdelta)
 y = sdelta*cl2
 z = math.degrees(math.atan(-y/x))
 
 if (x < 0):
     z = z+180.
 
 z2 = (z+180.) % 360. - 180.
 z2 = - math.radians(z2)
 anglerad2 = z2 - ((2*math.pi)*math.floor((z2/(2*math.pi))) )
 angledeg = (anglerad2*180.)/math.pi
 
 print 'Distance >> %.0f' % dist, ' [meters]'
 print 'Initial bearing >> ', angledeg, '[degrees]'