stella.acquire

Interface Horizontal

All Known Subinterfaces:

RayPath

All Known Implementing Classes:

AbstractHorizontalGeometry, CoudeFocusGeometry, DerotatorGeometry, NasmythFocusGeometry, PrimeFocusGeometry

public interface Horizontal

Provides horizontal coordinate system values, in particular azimuth, altitude, and parallactic angle. The three other values in the defining spherical triangle, latitude, hour angle and declination are *not* part of this interface.

To permit undefined values, we return Number objects rather than primitives.

Author:

wooz

Method Summary

Modifier and Type	Method and Description
Number	getAltitude() Returns the altitude of an predefined object or telescope pointing.
Number	getAzimuth() Returns the azimuth of an predefined object or telescope pointing.
Number	getParallacticAngle() Returns the parallactiv angle in degrees.

Method Detail

getAltitude

Number getAltitude()

Returns the altitude of an predefined object or telescope pointing.

Returns:

The height of the target in degrees. Null if undefined.

getAzimuth

Number getAzimuth()

Returns the azimuth of an predefined object or telescope pointing. Azimuth is zero at the meridian and counted positive to west.

Returns:

The azimuth of the target in degrees, starting S to W. Null if undefined.

getParallacticAngle

Number getParallacticAngle()

Returns the parallactiv angle in degrees. This is also the image rotation in a pure Gregorian focal plane.

Returns:

The parallactic angle η in degrees.