Examples for Qibla Calculation in Indonesia

In the previous post has been explained little about the formula of the direction of qibla for the region in Indonesia. so all places in Indonesia can use that formula to serve as a determinant of Qibla direction. Visit this Link. Qibla Formula for Indonesia

In this post, we will give 3 examples of calculations, first at Istiqlal Mosque-Jakarta, Baiturrahman Mosque-Semarang and al-Akbar Mosque-Surabaya.

Coordinate of Ka'ba in Google Earth

These 3 examples will be calculated by the coordinates of the Ka'ba that took from the Google Earth App. The coordinate of Ka'ba is 21˚ 25 '33,67" N and 39˚ 49 '33.27" E.

1. Istiqlal Mosque, Jakarta

Coordinate of Istiqlal in Google Earth

Qibla Calculation For Istiqlal Mosque :
a. Latitude: 6˚ 13' 00,97" S
b. Longitude: 106˚ 50' 11,54" E

Istiqlal Qibla Direction

c. λd = (λx - λx). = (106˚ 50' 11,54" -39˚ 49 '33.27") = 67˚ 0' 38,27"
d. Cotan QD = Tan φk * Cos φx / Sin λd - Sin φx / Tan λd.
Cotan QD = Tan 21˚ 25 '33,67" * Cos -6˚ 13' 00,97" / Sin 67˚ 0' 38,27" - Sin -6˚ 13' 00,97" / Tan 67˚ 0' 38,27".
QD = 64˚ 50' 23,85"
e. QA = 360 - QD
QA = 360 - 64˚ 50' 23,85"
QA = 295˚ 09' 36,15"

2. Baiturrahman Mosque, Semarang

Coordinate of Baiturrahman in Google Earth

Qibla Calculation For Baiturrahman Mosque:
a. Latitude: 6˚ 59' 00,23" S
b. Longitude: 110˚ 26' 45,67" E

Baiturrahman Qibla Direction

c. λd = (λx - λx). = (110˚ 26' 45,67" -39˚ 49 '33.27") = 70˚ 37' 12,4"
d. Cotan QD = Tan φk * Cos φx / Sin λd - Sin φx / Tan λd.
Cotan QD = Tan 21˚ 25 '33,67" * Cos -6˚ 59' 00,23" / Sin 70˚ 37' 12,4" - Sin -6˚ 59' 00,23" / Tan 70˚ 37' 12,4".
QD = 65˚ 30' 9,32"
e. QA = 360 - QD
QA = 360 - 65˚ 30' 9,32"
QA = 294˚ 29' 50,67"

3. al-Akbar Mosque, Surabaya

Coordinate al-Akbar Mosque from Google Earth

Qibla Calculation For al-Akbar Mosque :
a. Latitude: 7˚ 20' 10,95" S
b. Longitude: 112˚ 42' 54,29" E

Al-Akbar Qibla Direction

c. λd = (λx - λx). = (112˚ 42' 54,29" -39˚ 49 '33.27") = 72˚ 53' 21,02"
d. Cotan QD = Tan φk * Cos φx / Sin λd - Sin φx / Tan λd.
Cotan QD = Tan 21˚ 25 '33,67" * Cos -7˚ 20' 10,95" / Sin 72˚ 53' 21,02" - Sin -7˚ 20' 10,95" / Tan 72˚ 53' 21,02".
QD = 65˚ 56' 13,92"
e. QA = 360 - QD
QA = 360 - 65˚ 56' 13,92"
QA = 294˚ 03' 46,08"

From the 3 examples above can be concluded that true the direction of the Indonesia is North West, its value is about 294 degrees.
Additional added :
- Remember! that the value of North latitude and East longitude is positive and the value of South latitude and West longitude is negative. Visit Spherical Earth System.
- In the trigonometry formula above use Cotangen formula, if you using a calculator or excel program can use :
For Excel Atan (1/(Tan φk *......)) or Atan((Tan φk *.......)^-1)
For the Scientific calculator change "Atan" with "Shiftan".