120 likes | 132 Views
Explore the Newtonian viewpoint in astrometry and learn about spatial coordinate systems, reference frames, and coordinate transformations. Gain insights into inertial reference frames, parallel shifts of origin, and rotations. Discover the various spherical coordinates and their applications in astrometry.
E N D
Space • Newtonian Viewpoint • Spatial Coord. System = Reference Frame • Inertial Reference Frame • Spatial Coord. Transformation • Parallel Shift of Origin • Rotation Lecture Notes on Astrometry
Inertial Reference Frame (IRF) • RF where Law of Inertia is valid • Law of Inertia: No Force = Linear Motion • Galilei’s Principle of Relativity Physics are the same in any IRF • Parallel Shift of Linearly Moving Origin: IRF to IRF Lecture Notes on Astrometry
Spatial Coordinates • Rectangular Coord. • Spherical Coord. • Spheroidal Coord. Lecture Notes on Astrometry
Rectangular to Spherical Lecture Notes on Astrometry
Spherical to Rectangular Lecture Notes on Astrometry
Various Spherical Coordinates • Horizontal • Ecliptic • Equatorial • Galactic Lecture Notes on Astrometry
Horizontal Coordinates • Distance: r • Zenith Distance: z • Altitude=Elevation: a = Alt = El = 90°–z • Azimuth(al angle): A = Az Lecture Notes on Astrometry
Units of Angle • radian = rad • degree = deg = ° • minute = min = arc minute = ' • second = arc second = " = arcsec = as Lecture Notes on Astrometry
Units of Angle (contd.) • 1° = 60 ' = 3600 " • 180° = p radian • 1" ~ 4.848 mrad • 20" ~ 0.1 mrad = magnitude of aberration • 0.001" = mas, 0.000001" =mas, … Lecture Notes on Astrometry
Ecliptic Coordinates • Ecliptic = Mean Orbital Plane of Earth • Obliquity of Ecliptic: e • Solar System Bodies • Radius (Vector): r • (Ecliptic) Longitude: l • (Ecliptic) Latitude: b Ecliptic e Equator Equinox Lecture Notes on Astrometry
Equatorial Coordinates P • Basic Expression • Right Ascension: R.A. = a • Declination: Decl. = d • Parallax: p p r S AU E Lecture Notes on Astrometry
Units of Length • SI meter Speed of Light: c = 299792458 m/s • Astronomical Unit of length (AU) Rough: Mean radius of Earth’s orbit Precise: AU = c t, t = 499.00478353… s • Parsec (pc), Light Year (ly) 1 pc = AU/sin 1” ~ 30.9 Pm ~ 3.26 ly 1 ly = c x 1 jy ~ 9.5 Pm Lecture Notes on Astrometry