AppInventor: Menghitung Jarak dan Arah dari GPS

Sumber: https://sites.google.com/site/appinventor/distance-based-on-lat-long

Menghitung Jarak

Jarak:

distance = sqrt(x^2 + y^2)

Dimana:

x = 69.1 * (lat2 - lat1)
y = 69.1 * (lon2 - lon1) * cos(lat1/57.3)

Arah Kiblat

PI = Math.PI;
phiK = 21.4*PI/180.0;
lambdaK = 39.8*PI/180.0;
phi = lat*PI/180.0;
lambda = lon*PI/180.0;
psi = 180.0/PI*Math.atan2(Math.sin(lambdaK-lambda), Math.cos(phi)*Math.tan(phiK)-Math.sin(phi)*Math.cos(lambdaK-lambda));
return Math.round(psi);

Ref: http://www.islamicsoftware.org/qibla/qibla.html

Menghitung Arah

Arah:

β = atan2(X,Y),

Dimana

X = cos θb * sin ∆L
Y = cos θa * sin θb – sin θa * cos θb * cos ∆L

Referensi

• https://sites.google.com/site/appinventor/distance-based-on-lat-long
• http://www.igismap.com/formula-to-find-bearing-or-heading-angle-between-two-points-latitude-longitude/