The following practice problems are Coast Guard celestial navigation exam questions. Compute the GHA, LHA, and Declination for the Sun, Stars, and Planets.
Sun Only
1. On 26 February 1981, your vessel's 1615 ZT position is Lat. 25° 14.0' S, Long. 57° 22.0' W, when an azimuth the of Sun is observed. The chronometer time of the sight is 8h 13m 19s. The chronometer error is 01m 46s slow.
Answers
GHA 120° 33.3'
LHA 63° 11.3'
DEC 8° 30.8' S
2. On 9 February 1981, your 0739 zone time DR position is Lat. 23° 31.0' N, Long. 143° 41.0' E. At that time you observe the Sun. The chronometer reads 09h 37m 12s, and the chronometer error is 01m 52s slow.
Answers
GHA 141° 12.2'
LHA 284° 53.2'
DEC 14° 47.9' S
3. On 6 August 1981, your 1552 zone time DR position is Lat. 24° 26.0' S, Long. 73° 19.0' E. At that time you observe the Sun. The chronometer reads 10h 55m 07s, and the chronometer error is 02m 38s fast.
Answers
GHA 341° 39.9'
LHA 54° 58.9'
DEC 16° 39.8' N
4. On 6 November 1981, your vessel's 0706 zone time DR position is Lat. 25° 30.0' N, Long. 85° 35.0' W, when the Sun is observed. The chronometer time of the sight is 01h 03m 30s. The chronometer error is 02m 30s slow.
Answers
GHA 20° 35.0'
LHA 295° 00.0'
DEC 16° 03.1' S
Stars Only
1. On 16 June 1981, your 0430 zone time DR position is Lat. 29° 24.0' S, Long. 36° 16.0' E. At that time, you observe Vega. The chronometer reads 02h 32m 06s, and the chronometer error is 01m 54s fast.
Answers
GHA 22° 44.7'
LHA 59° 00.7'
DEC 38° 46.0' N
2. On 15 October 1981, your 0325 zone time DR position is Lat. 26° 51.0' N, Long. 138° 17.0' W. At that time, you observe Canopus. The chronometer reads 00h 25m 36s, and the chronometer error is 00m 20s slow.
Answers
GHA 114° 32.6'
LHA 336° 15.6'
DEC 52° 40.9' S
3. On 25 August 1981, your 1926 zone time DR position is Lat. 24° 17.0' S, Long. 5° 47.0' W. At that time you observe Fomalhaut. The chronometer reads 07h 26m 52s, and the chronometer error is 00m 15s fast.
Answers
GHA 281° 27.6'
LHA 275° 40.6'
DEC 29° 43.1' S
4. On 22 April 1981 , your 0344 zone time DR position is Lat. 21° 16.0' N, Long. 107° 32.0' W. At that time, you observe Spica. The chronometer reads 10h 45m 16s, and the chronometer error is 00m 25s fast.
Answers
GHA 170° 33.9'
LHA 63° 01.9'
DEC 11° 03.8' S
Planets Only
1. On 11 December 1981. your 1816 ZT DR position is Lat. 26° 30.0' N, Long. 140° 35.0' E. At That time you observe Venus. The chronometer reads 09h 14m 52s and the chronometer error is 01 m 02s slow.
Answers
GHA 274° 34.3'
LHA 55° 09.3'
DEC 21° 47.2' S
2. On 27 June 1981, your 1905 ZT DR position is Lat. 24° 35.0' N, Long. 50° 15.0' W. At that time you observe Saturn. The chronometer reads 10h 04m 26s and the chronometer error is 01m 20s slow.
Answers
GHA 63° 15.4'
LHA 13° 00.4'
DEC 0° 51.1' N
3. On 6 October 1981 , your 0416 zone time DR position is Lat. 25° 16.0' N, Long. 130° 25.0' E. At that time you observe Mars. The chronometer reads 07h 16m 22s, and the chronometer error is 00m 10s fast.
Answers
GHA 159° 40.7
LHA 290° 05.7'
DEC 15° 45.6' N
4. At 2326 ZT, on 22 June 1981, your vessel's position is Lat. 28° 30.0' N, Long. 150° 04.0' W. The planet Jupiter is observed. The chronometer reads 09h 24m 36s and is 01m 12s slow.
Answers
GHA 231°01.4'
LHA 80° 57.4'
DEC 0° 37.7' N
