neclib.coordinates.pointing_error.nanten2#

Aliases#

PointingError

Calculate pointing error offset.
class NANTEN2(*, model=None, **kwargs)[source]#

Bases: PointingError

Pointing model used in NANTEN2.

\[\begin{split}\Delta x =& \chi_{Az} \sin ( \omega_{Az} - Az ) \sin ( El ) \\ &+ \epsilon \sin ( El ) \\ &+ \chi_{2, Az} \sin ( 2 ( \omega_{2, Az} - Az ) ) \sin ( El ) \\ &+ \mathrm{d}Az \cos ( El ) \\ &+ \mathrm{d}e \\ &+ cor_\mathrm{v} \cos ( El + cor_\mathrm{p} ) \\ &+ \mathrm{d}e_\mathrm{radio} \\ \Delta Az =& \Delta x / \cos ( El ) \\ \Delta y =& - \chi_{El} \cos ( \omega_{El} - Az ) \\ &- \chi_{2, El} \cos ( 2 ( \omega_{2, El} - Az ) ) \\ &+ g_1 \cos ( El ) + g_2 \sin ( El ) \\ &+ \mathrm{d}el \\ &+ g_{ 1,\mathrm{radio} } \cos ( El ) + g_{ 2,\mathrm{radio} } \sin ( El ) \\ &- cor_\mathrm{v} \sin ( El + cor_\mathrm{p} ) \\ &+ \mathrm{d}el_\mathrm{radio} \\ \Delta El =& \Delta y\end{split}\]
Parameters:

  • dAz – Azimuth (not X) offset of encoder reading.

  • de – X collimation error.

  • chi_Az – Magnitude of tilt of azimuth axis.

  • omega_Az – Phase (azimuth direction) of tilt of azimuth axis.

  • eps – Skew angle (lack of orthogonality) between azimuth and elevation axes.

  • chi2_Az – Same as chi, but the period is 180deg in azimuth axis (harmonic component).

  • omega2_Az – Same as omega, but the period is 180deg in azimuth (harmonic component).

  • chi_El – Magnitude of tilt of elevation axis.

  • omega_El – Phase (azimuth direction) of tilt of elevation axis.

  • chi2_El – Same as chi, but the period is 180deg in azimuth axis (harmonic component).

  • omega2_El – Same as omega, but the period is 180deg in azimuth (harmonic component).

  • g – First order gravitational deflection coefficient.

  • gg – Second order gravitational deflection coefficient.

  • ggg – Third order gravitational deflection coefficient.

  • gggg – Fourth order gravitational deflection coefficient.

  • dEl (Angle = 0 << u.arcsec) – Elevation offset of encoder reading.

  • de_radio (Angle = 0 << u.arcsec) – Constant X (not azimuth) offset between optical and radio beam.

  • del_radio (Angle = 0 << u.arcsec) – Constant elevation offset between optical and radio beam.

  • cor_v (Angle = 0 << u.arcsec) – Amplitude of collimation error.

  • cor_p (Angle = 0 << u.deg) – Phase of collimation error, negative of elevation where the elevation component of collimation error is zero.

  • g_radio (float = 0) – First order gravitational deflection coefficient.

  • gg_radio (float = 0) – Second order gravitational deflection coefficient.

  • ggg_radio (float = 0) – Third order gravitational deflection coefficient.

  • gggg_radio (float = 0) – Fourth order gravitational deflection coefficient.

  • model (Optional[str]) –

apply_offset(az, el)[source]#

Compute the pointing error offset.

Parameters:

  • az (Quantity) – Azimuth at which the pointing error is computed.

  • el (Quantity) – Elevation at which the pointing error is computed.

Returns:

  • dAz – Offset in azimuth axis.

  • dEl – Offset in elevation axis.

Return type:

Tuple[Quantity, Quantity]

Important

The offset will be ADDED to encoder readings to convert it to true sky/celestial coordinate.

apply_inverse_offset(az, el)[source]#

Compute the pointing error offset.

Parameters:

  • az (Quantity) – Azimuth at which the pointing error is computed.

  • el (Quantity) – Elevation at which the pointing error is computed.

Returns:

  • dAz – Offset in azimuth axis.

  • dEl – Offset in elevation axis.

Return type:

Tuple[Quantity, Quantity]

Important

The offset will be ADDED to encoder readings to convert it to true sky/celestial coordinate.

fit(*args, **kwargs)[source]#

Fit the model to the measured pointing error parameters.