Projects:EASA PPL/Navigation: Difference between revisions

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(Created page with "* Units: ** 1NM = 1852m ** 1NM = 6080ft * Earth: ** Earth tilt angle: 23,44° ** Rhumb line: cutting all meridians at the same angle ** circumference: 21600 NM / 40000km * Sun: ** rise above the horizon: top and low latitude at summer and winter: 66° ** be at 90° above horizon: 23° ** civil twilight: sun 6° below horizon * Seasons: ** Due to inclination of the polar axis with the ecliptic plane *Time: **Twilight duration: longer at high latitudes *Magnetic: **CDMV...")
 
mNo edit summary
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* Units:
** 1NM = 1852m
** 1NM = 6080ft
* Earth:
* Earth:
** Earth tilt angle: 23,44°
** Earth tilt angle: 23,44°

Revision as of 17:42, 22 January 2023

  • Earth:
    • Earth tilt angle: 23,44°
    • Rhumb line: cutting all meridians at the same angle
    • circumference: 21600 NM / 40000km
  • Sun:
    • rise above the horizon: top and low latitude at summer and winter: 66°
    • be at 90° above horizon: 23°
    • civil twilight: sun 6° below horizon
  • Seasons:
    • Due to inclination of the polar axis with the ecliptic plane
  • Time:
    • Twilight duration: longer at high latitudes
  • Magnetic:
    • CDMVT: Compass - Deviation - Magnetic - Variation - True
    • Compass check swing: measure the angle between magnetic north and compass north
    • Agonic line: positions on line have 0° variation
    • Isogonic line: positions on line have same variation
    • Aclinic line: zero magnetic dip
  • Sphere / Latitude / Longitude:
    • Latitude: angular distance along meridian from equator to a parallel of the latitude
    • Longitude: arc at equator between greenwich meridian and location meridian
    • Distance on great circle: diff angle * 60NM = distance NM
    • Distance: diff longitude * 60NM * cos latitude = distance NM
    • parallels of latitude: = rhumb lines (constant direction)
  • Direct Mercator
    • great circle: curve concave to equator
    • rhumb line: straight line
    • parallels of latitude: are parallel straight lines unequally spaced
    • Meridians: parallel, equally spaced, vertical straight lines
  • Lambert conformal conic chart:
    • convergence of meridians is same as earth convergency at the parallel of origin
    • convergency: most accurate at parallel of origin
    • scale: quoted scale is correct along the two parallels, correct along a parallel of latitude
    • great circles: are curves concave to the parallel of origin
    • straight line on lambert chart: is approximately a great circle
    • parallels: represented by arcs of concentric circles
  • GPS
    • Minimum satellites: 4 (without RAIM)
    • Minimum satellites safe: 6 (with RAIM)
    • Orbit: Circular / 12 hours
    • Satellites: 6 orbital planes with 4 sats in each plane (Total 24)
    • Height above MSL: 20200km / 10900 NM
    • RAIM (Receiver Autonomous Integrity Monitoring): verify integrity of navigation data
    • Frequency: UHF
    • Accuracy: ICAO average 95%: 13m horizontally
    • Decrease accuracy: satellite clock, satellite ephemeris, atmospheric propagation
    • Civil aviation: L1 coarse acquisition with selected availability (C/A) (1575 MHz, 2 codes)
    • Coordinate system: WGS 84 (ellipsoid)
    • Segments: control, space, user
    • Height: above WGS-84 ellipsoid
    • Inclination: angle between orbital plane and equatorial plane
    • Orbital plane: inclined 55° to the equatorial plane
    • PRN (Pseudo random noise): code to identify satellites
    • Navigation message: Almanac data, satellite status
  • VOR
    • Phase difference
  • DME
    • colocated with VOR: DME ident can be heard once every 40s
  • Transponder
    • 2 modes, 4096 codes each