Projects:EASA PPL/Navigation: Difference between revisions

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* Earth:
== Earth ==
** Earth tilt angle: 23,44°
* Earth tilt angle: 23,44°
** Rhumb line: cutting all meridians at the same angle
* Rhumb line: cutting all meridians at the same angle
** circumference: 21600 NM / 40000km
* circumference: 21600 NM / 40000km
* Sun:
 
** rise above the horizon: top and low latitude at summer and winter: 66°
== Sun ==
** be at 90° above horizon: 23°
* Rise above the horizon: top and low latitude at summer and winter: 66°
** civil twilight: sun 6° below horizon
* Be at 90° above horizon: 23°
* Civil twilight: sun 6° below horizon (30min before/after sunrise/sunset)
* Seasons:  
* Seasons:  
** Due to inclination of the polar axis with the ecliptic plane
** Due to inclination of the polar axis with the ecliptic plane
*Time:
*Time:
**Twilight duration: longer at high latitudes
**Twilight duration: longer at high latitudes
*Magnetic:
 
**CDMVT: Compass - Deviation - Magnetic - Variation - True
== Magnetic ==
**Compass check swing: measure the angle between magnetic north and compass north
*CDMVT: Compass - Deviation - Magnetic - Variation - True
**Agonic line: positions on line have 0° variation
*Compass check swing: measure the angle between magnetic north and compass north
**Isogonic line: positions on line have same variation
*Agonic line: positions on line have 0° variation
**Aclinic line: zero magnetic dip
*Isogonic line: positions on line have same variation
*Sphere / Latitude / Longitude:
*Aclinic line: zero magnetic dip
**Latitude: angular distance along meridian from equator to a parallel of the latitude
 
**Longitude: arc at equator between greenwich meridian and location meridian  
== Sphere / Latitude / Longitude: ==
**Distance on great circle: diff angle * 60NM = distance NM
*Latitude: angular distance along meridian from equator to a parallel of the latitude
**Distance: diff longitude * 60NM * cos latitude = distance NM
*Longitude: arc at equator between greenwich meridian and location meridian
**parallels of latitude: = rhumb lines (constant direction)
*Distance on great circle: diff angle * 60NM = distance NM
*Direct Mercator
*Distance: diff longitude * 60NM * cos latitude = distance NM
**great circle: curve concave to equator
*parallels of latitude: = rhumb lines (constant direction)
**rhumb line: straight line
 
**parallels of latitude: are parallel straight lines unequally spaced
== Direct Mercator ==
**Meridians: parallel, equally spaced, vertical straight lines
*great circle: curve concave to equator
*Lambert conformal conic chart:
*rhumb line: straight line
**convergence of meridians is same as earth convergency at the parallel of origin
*parallels of latitude: are parallel straight lines unequally spaced
**convergency: most accurate at parallel of origin
*Meridians: parallel, equally spaced, vertical straight lines
**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
== Lambert conformal conic chart: ==
**straight line on lambert chart: is approximately a great circle
*convergence of meridians is same as earth convergency at the parallel of origin
**parallels: represented by arcs of concentric circles
*convergency: most accurate at parallel of origin
*GPS
*scale: quoted scale is correct along the two parallels, correct along a parallel of latitude
**Minimum satellites: 4 (without RAIM)
*great circles: are curves concave to the parallel of origin
**Minimum satellites safe: 6 (with RAIM)
*straight line on lambert chart: is approximately a great circle
**Orbit: Circular / 12 hours
*parallels: represented by arcs of concentric circles
**Satellites: 6 orbital planes with 4 sats in each plane (Total 24)
 
**Height above MSL: 20200km / 10900 NM
== GPS ==
**RAIM (Receiver Autonomous Integrity Monitoring): verify integrity of navigation data
*Minimum satellites: 4 (without RAIM)
**Frequency: UHF
*Minimum satellites safe: 6 (with RAIM)
**Accuracy: ICAO average 95%: 13m horizontally
*Orbit: Circular / 12 hours
**Decrease accuracy: satellite clock, satellite ephemeris, atmospheric propagation
*Satellites: 6 orbital planes with 4 sats in each plane (Total 24)
**Civil aviation: L1 coarse acquisition with selected availability (C/A) (1575 MHz, 2 codes)
*Height above MSL: 20200km / 10900 NM
**Coordinate system: WGS 84 (ellipsoid)
*RAIM (Receiver Autonomous Integrity Monitoring): verify integrity of navigation data
**Segments: control, space, user
*Frequency: UHF
**Height: above WGS-84 ellipsoid
*Accuracy: ICAO average 95%: 13m horizontally
**Inclination: angle between orbital plane and equatorial plane
*Decrease accuracy: satellite clock, satellite ephemeris, atmospheric propagation
**Orbital plane: inclined 55° to the equatorial plane
*Civil aviation: L1 coarse acquisition with selected availability (C/A) (1575 MHz, 2 codes)
**PRN (Pseudo random noise): code to identify satellites
*Coordinate system: WGS 84 (ellipsoid)
**Navigation message: Almanac data, satellite status
*Segments: control, space, user
*VOR
*Height: above WGS-84 ellipsoid
**Phase difference
*Inclination: angle between orbital plane and equatorial plane
*DME
*Orbital plane: inclined 55° to the equatorial plane
**colocated with VOR: DME ident can be heard once every 40s
*PRN (Pseudo random noise): code to identify satellites
*Transponder
*Navigation message: Almanac data, satellite status
**2 modes, 4096 codes each
 
== VOR ==
*Phase difference
 
== DME ==
*colocated with VOR: DME ident can be heard once every 40s
 
== Transponder ==
*2 modes, 4096 codes each

Latest revision as of 17:45, 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 (30min before/after sunrise/sunset)
  • 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