Coordinate Systems Flashcards
(33 cards)
what does the Equinoctial System of Coordinates define?
the position of a celestial body - relative to the Equinoctial + the Greenwich Celestial Meridian
where can you find the Equinoctial System of Coordinates?
Nortical Almanac
what is Declination (Dec)?
the angular distance of a body North or South of the Equinoctial
what is Declination equivalent to?
Latitude
what is Polar Distance?
the angular distance from the pole to the body
what is the complement of Declination?
Polar Distance
what is the Greenwich Hour Angle?
angular distance of a body west of the Greenwich celestial merridian
what does GHA stand for?
Greenwich Hour Angle
what is the GHA approximately equivalent to?
westerly Longitude
what does SHA stand for?
Sidereal Hour Angle
What is the SHA?
angular distance of a body west of the 1st point of Aries
how do you find the GHA of a star?
adding GHA Aries to SHA of the star
what is the Geographical Position of a body?
point on Earth’s surface directly below the body
what does Latitude equal?
Declination
What does Westerly Longitude equal?
Greenwich Hour Angle
what does LHA stand for?
Local Hour Angle
what is Local Hour Angle?
angular distance of a body west of the observer’s celestial meridian
what does the Horizontal System of Coordinates define?
the position of a celestial body relative to the observer
what is the PZX triangle?
a spherical triangle on celestial sphere formed by the observer’s meridian PZ, of a body PX and vertical circle through observer’s Zenith + body ZX
what are the apexes of the PZX triangle?
- pole P
- observer’s Zenith Z
- body X
what are the coordinates of Z in PZX triangle?
Latitude + Longitude
what are the coordinates of X in PZX triangle?
Declination + Local Hour Angle
what is PZ the complement of in PZX triangle?
Latitude
what is PX in PZX triangle?
Polar Distance
