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1 NavigationNavigation
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2 Chapter 6 Sight Planning NavigationNavigation
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Set up star finder for any location & time Plot planets, sun & moon on star finder Use “Sight Planner “ in Celestial Tools Select suitable bodies for fixes Identify unknown celestial body 3 Learning Objectives
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4 NavigationNavigation
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5 Sight Considerations Stars & Planet Sights: Usable observation period - 15 to 45 min Morning: maybe an hour before sunrise Evening: brightest until no longer see horizon Moon Sights: Daytime: 2-body fix with sun Twilight: 2/3-body fix with sun/star/planet
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6 Sight Considerations Twilight Sights: Predict altitudes & Zn Morning - bodies to the west first Brightest bodies first Take sights on any bright body Daylight Sights: Sun near MT, bearing changes rapidly Moon/Venus occasionally visible Sun-Moon after/before 1 st & last quarter
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7 Sight Considerations Ideal LOP separations for fix: 90° for 2-body, minimum 45° 120° for 3-body, minimum 30° Sun 0830 Moon 0845 Sun 0830 Moon 0845 Venus 0850 MPP
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8 Sight Planning Internet & App’s Computers – Celestial Tools Star Finder Nautical Almanac
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Manual Tool – backup For any given time & location, determine: Approximate altitude & Zn of bodies Navigational stars, sun, moon & navigational planets 9 Star Finder
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10 Star Base (white disc) Red Template Blue Template Star Finder
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11 Star Base Celestial Sphere Northern Hemisphere Southern Hemisphere Poles at center of disc Celestial Equator 4” circle Shows Navigational Stars Relative magnitude LHA scale, Aries at 0° Right Ascension (RA) Star Finder RA: 24° SHA:336° Total:360°
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12 Overlay Plot planets, sun & moon North/South side Declination circles Meridian angle scale Plotting slot Star Finder Red Template
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Blue Template 13 Overlay 10° intervals, 5° - 85° Nearest your DR North/South side Blue grid visible area (mount & align LHA 310°) Center cross is zenith Outer ring is horizon Radial lines are azimuth Curved lines are altitude Star Finder
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Blue Template 14 LATITUDE 45°N overlay Mount on Star Base Align arrow with LHA 259° 7 - 1 st Mag stars visible? Star Finder Exercise Antareshs 18Zn 192 Spicahs 14Zn 240 Arcturus hs 45Zn 252 Capellahs 2Zn 179 Denebhs 55Zn 70 Vegahs 75Zn 115 Altairhs 42Zn 125 What are their hs & Zn? What about the sun, moon, Venus, Mars, Jupiter, & Saturn?
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15 Star Finder Exercise 4/1445 25.6N45.492 30.0W6 45.4 45.0 0.4 50N 45N 5 0435 0446 -11 0.180446 92.5 90.0 2.5 1004460456 +5 0956 9 56 337 42.1 14 02.3 351 44.4 -92 30.0 259 14.4 259 314 56.3 269 42.0 333 17.0 336 34.0 287 09.7 142 14.4 314.9 269.7 333.3 336.6 287.2 142.2 351.7 36.8 82.0 26.7 23.4 72.8 217.8 9.5N 19.9N 10.1N 9.4N 22.1N 12.0S Morning CT 14 02.3 1. Determined LMT for DR Lat. 2. Adjust LMT for DR Lo. 3. Compute UT.4. Determine LHA of Aries. 5. Look up GHA, SHA and Dec. 6. Enter the GHA for Aries. 7. Determined RA for bodies.
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16 Star Finder Exercise Mount Red Template on Star Base Align arrow with RA for Sun Using slot on template, place dot at 10° N Dec and label with symbol (use pencil) Repeat for other bodies RA 37° 82° 27° 23° 73° 218° Body Sun Moon Venus Mars Jupiter Saturn Dec 10° N 20° N 10° N 09° N 22° N 12° S
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17 Star Finder Exercise ħ Replace with LATITUDE 45°N overlay Align arrow with LHA 259° What are the hs & Zn for these bodies? Saturn: hs 22° Zn 223°
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Take bearing of body Set star finder for time of sight Altitude & approx. bearing Bodies on star base located in vicinity Reduce sight If correct, intercept close to DR If star is not very bright, may not be nav. star List of stars, pg 268 - 273 NA Estimate SHA & Dec; look it up in star list 18 Star Identification Hudson WiMar 24, 2013 10:05 PM
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19 Celestial Tools
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20 Next week bring your calculator or abacus CHAPTER 3 LHA, Dec, Ho NavigationNavigation
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21 The End Sight Planning
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