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HomeworkQ & A

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Chapter 8Chapter 8

Plotting Celestial Plotting Celestial LOPsLOPs

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Objectives:

■ Set up a USPS Constant Latitude Scale (CLS) Small Area Plotting Sheet (SAPS).

■ Plot a single celestial LOP.

■ Plot a celestial running fix.

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Practical Exercise

1. Follow the Student Manual for guidance.

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2. Plot the following data. Use a different CLS sheet for each plot. Establish the EP and record its coordinates to the nearest minute in the lower part of the plot.

DR L DR Lo ZT a Zn Body

a. 23°19.6'S 67°14.2'W 0524 3 nm A 101° Sun LL

EP: L 23° 19.2'S, Lo 67° 17.2'W rounded to L 23° 19'S, Lo 67° 17'W

b. 14°19.5'N 152°49.8' E 1810 4 nm T 228° Sun UL

EP: L 14° 16.9'N, Lo 152° 46.6'Erounded to L 14° 17'N, Lo 152° 47'E

Ref.: ¶ 15 - 23

Solution: CLS Plot – Click to view Figure IM08-2a

Solution: CLS Plot – Click to view Figure IM08-2b

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3. Refer to the USPS SR96 Forms you started in Chapter 6, Homework #6a & #6b, and completed in Chapter 7, Homework #15a & #15b. Plot the data that resulted from these calculations. Use a different CLS sheet for each plot. Establish the EP and record its coordinates to the nearest minute in the lower part of the plot.

a. EP: L 30° 07.1'N, Lo 85° 41.7'W rounded to L 30° 07'N, Lo 85° 42'W

b. EP: L 41° 16.4'N, Lo 73° 04.8'Wrounded to L 41° 16'N, Lo 73° 05'W

Ref.: ¶ 15 - 23

Solution: CLS Plot - Click to view Figure IM 8-3a

Solution: CLS Plot - Click to view Figure IM 8-3b

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4. Plot the following data using a CLS sheet for the plot. Reduce each sight of the sun by calculator method and plot the 0800 EP and the 1200 Running Fix positions. Record the 1200 RFix coordinates to the nearest minute in the lower part of the plotting sheet.

Refer to Appendix B, Excerpts from the Nautical Almanac. Date is 06 December. The course is 140° True; speed is 15 knots. Height of eye is 8.0 feet. Index correction is +2.2'. Watch error is 1 second fast.

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Problem 4. Continued from previous slide

Data for the 0800 Sun LOP is:

DRL DRLo Watch Time hs body4°54.6'S 45°10.3 'E 08-00-09 31°36.3' Sun LL

At 1020, you change course to 015° True, Speed is maintained at 15 knots. Data for the 1200 Sun LOP is:

DR L DR Lo Watch Time hs body(determine from CLS plot) 12-00-25 71 °52.3' Sun LL

Solution: SR by calculator method and CLS Plot.Click to see Figures IM 8-4a, 4b & 4c

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4. Continued from previous slide

RFix (Sun LOPs) L 4°54.2'S, Lo 45°45.1'E; rounded to L 4°54'S, Lo 45°45'E;

0800 Sun intercept 4.0nm T, Zn 114°;

1200 Sun intercept 3.9 nm A, Zn 189°

[1200 DR L 4°57.3', Lo 45°39.4'E]

Ref.: ¶ 15 – 20 & 29 - 32

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Chapter 8Chapter 8

Plotting Celestial Plotting Celestial LOPsLOPs