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Navigation. Sight Folder Requirements. hs between 15 º and 75 º ; LOP with 3.0nm. Line of Position (LOP) using the Sun from run of at least three qualified sights Line of Position (LOP) using the Moon from run of at least three qualified sights
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Sight Folder Requirements hs between 15º and 75º; LOP with 3.0nm Line of Position (LOP) using the Sun from run of at least three qualified sights Line of Position (LOP) using the Moon from run of at least three qualified sights Line of Position (LOP) using a Star from run of at least three qualified sights Line of Position (LOP) using a Planet from run of at least three qualified sights Meridian Transit of the Sun from run of at least three sights with one sight within 10 sec of MT 2-body Fix using any two bodies from a run of at least three qualified sights each; taken within 20 mins and intersection of LOP’s not less than 45º 3 Any one of these sights must be reduced and plotted by the Nautical Almanac Sight Reduction (NASR) method. One sight from each of the other three must be reduced and plotted using the Law of Cosines (LOC) method. 3 APPENDIX D 3 3 Sight within 10sec of calculated MT reduced using the Meridian Transit SR form. 3 Selected sights must be reduced and plotted by both the NASR and LOC method. 6 Minimum of 21 sights 7 SR Form / 6 CLS SAP
Navigation Chapter 1 View of our Solar System Chapter 2 Sunrise … Sunset
Apparent motion ‘First Point of Aries’ Sidereal Hour Angle (SHA) Difference between solar & sidereal time Difference between LMT & ZT Determine ZT Sun/Moon rise/set Determine ZT civil & nautical twilight Learning Objectives 5
Jun 21 Sep 22 Dec 21 Mar 20 Night Sky -21.3sec +29.9sec +31.1sec -18.1sec Solar Time Orbit time: 31,536,000 SI seconds 86,400.002 seconds/day 6
Night Sky SUMMER SOLSTICE NP Jun 21 Dec 23º 26.1’ N SP 7
Night Sky AUTUMNAL EQUINOX NP Sep 22 Dec 0º 00.0’ SP 8
Night Sky WINTER SOLSTICE NP Dec 21 Dec 23º 26.1’ S SP 9
Night Sky VERNAL EQUINOX NP Mar 20 Dec 0º 00.0’ SP First point of Aries () 10
Night Sky Sidereal Time 23hr 56min 4.0916sec 11
Celestial Equator Ecliptic Aries 12
GHA = SHA + GHA Dubhe SHA 193° 51.3’ Celestial Equator N P Aries NA1800 GHA 88° 25.8’ Aries G 13
Sight Reduction Form 19 Mar 20xx Dubhe 13-00-00 00-03 45 00 0 + 13-00-00 92 30 0 5 + 18-00-00 20 Mar 20xx g ? 193 51 3 G 18 88 25 8 ? 0 00 0 00 - 00 ? 282 17 1 92 30 0 – ? 189 47 1 14
Night Sky VENUS MARS JUPITER MOON SATURN 15
Navigator’s Solar System Sun – Moon – 4 Planets – 57 Stars -26.7 -13.2 NA South Declination 1st Magnitude North Declination 1st Magnitude Sirius (-1.5) Canopus (-0.7) Rigil Kentaurus (-0.3) Rigel (0.1) Achernar (0.5) Spica (1.0) Antares (1.0) Fomalhaut (1.2) Acrus (1.3) Adhara (1.5) Gacrux (1.6) Shaula (1.6) Arcturus (0.0) Vega (0.0) Betelgeuse (0.1) Capella (0.1) Procyon (0.4) Altair (0.8) Aldebaran (0.9) Regulus (1.1) Pollux (1.1) Deneb (1.3) Bellatrix (1.6) 16
Betelgeuse Bellatrix Alnilam Capella Rigel 17
Horizon, planets and brightest stars visible Morning Sights Between beginning of CT and sunrise Evening Sights Between sunset and end CT 0643 – 0712 29min 1923 – 1952 29min 18
Solar P-hen-omen-a • Sunrise (SR) • Sunset (SS) • Twilight • Civil Twilight (CT) • Nautical Twilight (NT)
Local Mean & Zone Time Local Mean Time (LMT) – based on the mean sun with reference to the local celestial meridian. DLo – difference between your Lo and referenced meridian. Zone Time (ZT) – based on the nearest meridian with a longitude exactly divisible by 15°.
Local Mean & Zone Time 1814 ZT 1814 LMT 92.5° W ? 97.5° W ZM 90° W 82.5° W ZD +6
Local Mean & Zone Time Zone Time: 1814 Location: Lo 92° 42.6’ W • FIND ZM: • FIND DLo: • DLo to TIME: • LMT: 92° 43’ – 90° = 2° 43’ = 2.7° 2.7° x 4min = 10.8min; rounded 11min (15° in 1hr; 1° in 4min) 1814 - 11min = 1803
Predicting Phenomena Location: L 48° 20.7’ N Lo 92° 42.6’ W Find LMT for beginning of morning CT. Tab Lat LMT CT 50° 0718 45°0704 5°14min Latitude: 48° 20.7’ N 45° 00.0’ N 3° 20.7’ = 3.35°
Predicting Phenomena Diff Tab Lat: 5° Diff LMT: 14min Diff Lat: 3.35° LMT CT L 45° N 0704 Corr for L 48° 20.7’ N 9min LMT CT L 48° 20.7’ N 0713 +
Predicting Phenomena LMT CT L 48° 20.7’ N 0713 DLo = DR Lo – ZM Lo 92° 43’ W ZM 90° 00’ W DLo 2° 43’ W = 2.7° 2.7° x 4min = 10.8 rounded 11min LMT 0713 DLo (W) + 11 LMT for CT 0724
Predicting Phenomena How would I use this skill?
Predicting Phenomena ABOARD MOVING VESSEL “First Estimate” ZT 0000 GPS Position L 45° 26’ N; Lo 11° 39’ W Course 115° T; Speed 9.0kn Tab L 45° N NT = 0627 (Lo 15° W) When do you need to be on deck for morning sights?
Predicting Phenomena ABOARD MOVING VESSEL “First Estimate” 0627-0000 = 6hr 27min = 387min How far will you travel by tab LMT NT? Plot projected 0627 DR position
Predicting Phenomena 0000 GPS 0000 GPS L 45° 26’ N Lo 11° 39’ W C 115 S 9.0 20’ 10’ Projected L 45° 01.5’ N Lo 10° 46.4’ W 0627 45°N 50’ 50’ 40’ 30’ 20’ 10’ 11° W 40’
Predicting Phenomena ABOARD MOVING VESSEL “First Estimate” Projected DR L 45° 01.5’ N - Lo 10° 46.4’ W Tab L LMT NT 50° N 0637 45° N0627 5°10min 45° 01.5’ N – 45° 00.0’ N = 1.5’ What’s are the differences in Tab Lat & LMT NT? What’s the difference between EP Lat & Tab L?
Predicting Phenomena ABOARD MOVING VESSEL “First Estimate” What’s the LMT NT at projected Lat? LMT NT: 0627 + 0 = 0627
Predicting Phenomena ABOARD MOVING VESSEL “First Estimate” LMT Projected Lat = 0627 DLo: 15° 00.0’ W – 10° 46.4’ W 4° 13.6’ W = -4.2° What’s the LMT NT at projected DR? What’s the arc to time conversion? 4.2° x 4min = 16.8min rounded 17min What’s your DLo? LMT NT: 0627 – 17min = 0610
Navigation Next week bring your calculator or abacus CHAPTER 6 SIGHT PLANNING