Saturday, January 3, 2009

LOP Altitude and Azimuth Questions

Line of Position - Sun (Computed Altitude and Azimuth)
1. At 0600 ZT, on 24 July 1981, your DR position is LAT 22°37.0' N, LONG 32°45.0' W. You are steering 185°T at a speed of 20.0 knots. Determine the computed altitude (Hc) and azimuth (Zn) for an observation of the Sun's lower limb taken at 1030 ZT. At this time the chronometer reads 00h 30m 16s and is 0m 31s slow.
A. Hc 64°27.5' - Zn 092.3°
B. Hc 64°30.8' - Zn 090.1°
C. Hc 64°41.7' - Zn 087.8°
D. Hc 64° 44.2' -Zn 094.7°

2. On 18 August 1981, at 0600 ZT, morning stars were observed, and the vessel's position was determined to be LAT 19°48'N, LONG 108° 34'W. Your vessel is steaming on course 166°T at a speed of 16 knots. An observation of the Sun's lower limb is made at 1036 ZT. The chronometer reads 05h 34m 48s and is slow 01m 24s. What is the computed altitude (Hc) and azimuth (Zn) for this 1036 ZT observation using the assumed position method?
A. Hc 65°18.5' - Zn 102.1°
B. Hc 65°14.8' - Zn 100.4°
C. Hc 65°11.3' - Zn 099.4°
D. Hc 65° 07.2' - Zn 101.2°

Line of Position - Sun (Observed Altitude and Azimuth)
3. On 8 August 1981, at 0545 ZT, morning stars were observed, and the vessel's position was determined to be LAT 26°16.0'S, LONG 94°16.0'E. Your vessel is steaming at 20.0 knots on a course of 346°T. A sextant observation of the Sun's lower limb is made at 0905 ZT. The chronometer reads 03h 02m 52s, and the sextant altitude (hs) is 38°07.5'. The index error is 5.2' off the arc, and the chronometer error is 2m 17s slow. Your height of eye on the bridge is 72 feet (22.0 meters). What is the observed altitude (Ho) and azimuth (Zn) of this sight using the assumed position?
A. 38°19.4' -048.4° T
B. 38°19.4' - 131.6° T
C. 38°54.9' -048.4° T
D. 38°54.9' -131.6° T

4. On 9 November 1981, at 0426 ZT, your position was LAT 25°17.0'S, LONG 154°16.0'E. Your vessel is steaming at 14.0 knots on course 066°T. A sextant observation ofthe Sun's lower limb is made at 0837 ZT. The chronometer reads 10h 35m 21s, and the sextant altitude (hs) is 50°26.9'. The index error is 1.5' on the arc, and the chronometer error is 01m 48s slow. Your height of eye on the bridge is 56.0 feet. What is the observed altitude (Ho) and azimuth (Zn) of this sight using the assumed position?
A. 50°18.1' - 086.3° T
B. 50°18.1' - 093.7° T
C. 50°33.5' - 085.9° T
D. 50°33.5' - 093.7° T

Line of Position - Sun (Azimuth and Intercept)
5. On 12 April 1981, at 0515 ZT, morning stars were observed, and the vessel's position was determined to be LAT 21°05'S, LONG 16°30'W. Your vessel is steaming at 19 knots on a course of 278°T. A sextant observation of the Sun's lower limb is made at 0930 ZT. The chronometer reads 10h 28m 25s, and the sextant altitude (hs) is 40° 15 .9'. The index error is 2.5' off the arc, and the chronometer error is 2m 15s slow. Your height of eye on the bridge is 57 feet. What are the intercept (a) and azimuth (Zn) from the assumed position of this sight?
A. Zn 057.7° - a 15.4' Towards
B. Zn 057.0° - a 17.7' Away
C. Zn 122.3° - a 17.7' Away
D. Zn 123.0° - a 22.7' Away

6. On 4 June 1981, at 0630 ZT, morning stars were observed, and the vessel's position was determined to be LAT 26°15'S, LONG 121°20'W. Your vessel is steaming at 13.0 knots on a course of 246°T. A sextant observation ofthe Sun's lower limb is made at 0915 ZT. The chronometer reads 05h 14m 27s, and the sextant altitude is 25°57.8'. The index error is 2.1' off the arc, and the chronometer error is 0m 53s slow. Your height of eye is 39.0 feet. What is the intercept (a) and azimuth (Zn) of this sight using the assumed position method?
A. Zn 044.6° - a 1.7' Away
B. Zn 044.6° - a 2.5' Towards
C. Zn 135.1° - a 1.7' Away
D. Zn 135.1° - a 2.5' Towards
 
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