stella.acquire

Interface CcdReference

All Known Subinterfaces:

RayPath

All Known Implementing Classes:

AbstractHorizontalGeometry, CoudeFocusGeometry, DerotatorGeometry, NasmythFocusGeometry, PrimeFocusGeometry

public interface CcdReference

Defines methods for the reference frame of the CCD with respect to right ascension-declination and horizontal systems. In figure A

the reference frame is depicted, where

• Δα and Δδ is difference in right ascension and declination to proposed pointing center
• η (red) is the parallactic angle.
• θ (blue) is getHorizontalAngle(). For many systems this will be either zero or fixed.
• χ (green) is getEquatorialAngle().

If the chirality of the CCD is negative, the x axis points to left. The center of the CCD (center of the coordinate system) is the pivotal point in Pivoting, it coincides with the pointing center in Pointing.

Author:

wooz

Method Summary

Modifier and Type	Method and Description
double	getArcsecPerPixel() Arcseconds per pixel guider scale.
double	getChirality() Chirality of CCD system, -1 for left-handed, +1 for right-handed.
Number	getEquatorialAngle() Returns the angle between the y-axis of the CCD and the declination axis.
Number	getHorizontalAngle() Returns the angle between the y-axis of the CCD and the elevation axis.

Method Detail

getEquatorialAngle

Number getEquatorialAngle()

Returns the angle between the y-axis of the CCD and the declination axis. If the CCD has negative chirality, this is also the angle to the right-ascension axis.

getHorizontalAngle

Number getHorizontalAngle()

Returns the angle between the y-axis of the CCD and the elevation axis. Refer also to the figure A. If the CCD has positive chirality, this is also the angle to the azimuth axis.

getArcsecPerPixel

double getArcsecPerPixel()

Arcseconds per pixel guider scale.

getChirality

double getChirality()

Chirality of CCD system, -1 for left-handed, +1 for right-handed. Right ascension and declination is the most prominent left-handed coordinate system in astronomy.