Alignment Class Reference

The Alignment class This converts between the mount axis angles and the sky hour angle and declination angles. Initially for equatorial fork and GEM mounts. To start with there is a unity mount model. The axis zeros correspond to the declination and hour angle zeroes and the directions match in the Northern henisphere For the GEM the normal pointing state is defined as positive hour angles, ie. with the mount on the East, looking West Both axis directions are mirrored in the South. More...

#include <scopesim_helper.h>

Public Types
enum	MOUNT_TYPE { ALTAZ , EQ_FORK , EQ_GEM }

Public Member Functions
	Alignment ()
void	mountToApparentRaDec (Angle primary, Angle secondary, Angle *apparentRa, Angle *apparentDec)
	mountToApparentRaDec: convert mount position to apparent Ra, Dec
void	apparentRaDecToMount (Angle apparentRa, Angle apparentDec, Angle *primary, Angle *secondary)
void	setCorrections (double ih, double id, double ch, double np, double ma, double me)
	setCorrections set the values of the six corrections
void	setCorrections (double *coeffs)
void	setFlipHourAngle (double deg)
const char *	getDeviceName ()
double	ih ()
double	id ()
double	np ()
double	ch ()
double	ma ()
double	me ()
void	instrumentToObserved (Angle instrumentHa, Angle instrumentDec, Angle *observedHa, Angle *observedDec)
void	observedToInstrument (Angle observedHa, Angle observedDec, Angle *instrumentHa, Angle *instrumentDec)
void	mountToApparentHaDec (Angle primary, Angle secondary, Angle *apparentHa, Angle *apparentDec)
	mountToApparentHaDec: convert mount position to apparent Ha, Dec
void	mountToInstrumentHaDec (Angle primary, Angle secondary, Angle *instrumentHa, Angle *instrumentDec)
	mountToInstrumentHaDec: convert mount axis positions to instrument (encoder) HA/Dec without applying the Wallace pointing-model corrections.
void	instrumentHaDecToMount (Angle instrumentHa, Angle instrumentDec, Angle *primary, Angle *secondary)
void	apparentHaDecToMount (Angle apparentHa, Angle apparentDec, Angle *primary, Angle *secondary)
	apparentHaDecToMount
Angle	lst ()

Public Attributes
Angle	latitude = 0
Angle	longitude = 0
MOUNT_TYPE	mountType = EQ_FORK

Detailed Description

The Alignment class This converts between the mount axis angles and the sky hour angle and declination angles. Initially for equatorial fork and GEM mounts. To start with there is a unity mount model. The axis zeros correspond to the declination and hour angle zeroes and the directions match in the Northern henisphere For the GEM the normal pointing state is defined as positive hour angles, ie. with the mount on the East, looking West Both axis directions are mirrored in the South.

This uses a simple mount model based on Patrick Wallace's paper. this is at http://www.tpointsw.uk/pointing.htm

Terminology is as defined in figure 1:

Apparent Ra and Dec - what is (incorrectly) called JNow. positions are apparentRa and apparentDec apply local sidereal time Apparent Ha and Dec, positions are apparentHa and apparentDec ignore diurnal effects ignore refraction (for now) Observed Place These are the mount coordinates for a perfect mount, positions are observedHa and observedDec apply telescope pointing corrections Instrument Place these are the mount coordinates for the mount with corrections, values are instrumentHa and instrumentDec for a GEM convert to axis coordinates ( this isn't in the paper). Mount Place these give primary (ha) and secondary (dec) positions

At present AltAz mounts are not implemented

Definition at line 409 of file scopesim_helper.h.

Member Enumeration Documentation

MOUNT_TYPE

enum Alignment::MOUNT_TYPE

Enumerator
ALTAZ
EQ_FORK
EQ_GEM

Definition at line 414 of file scopesim_helper.h.

Constructor & Destructor Documentation

Alignment()

Alignment::Alignment ( )

inline

Definition at line 412 of file scopesim_helper.h.

Member Function Documentation

apparentHaDecToMount()

void Alignment::apparentHaDecToMount	(	Angle	apparentHa,
		Angle	apparentDec,
		Angle *	primary,
		Angle *	secondary
	)

apparentHaDecToMount

Parameters

ha
apparentDec
primary
secondary

Definition at line 376 of file scopesim_helper.cpp.

apparentRaDecToMount()

void Alignment::apparentRaDecToMount	(	Angle	apparentRa,
		Angle	apparentDec,
		Angle *	primary,
		Angle *	secondary
	)

Definition at line 407 of file scopesim_helper.cpp.

ch()

double Alignment::ch ( )

inline

Definition at line 472 of file scopesim_helper.h.

getDeviceName()

const char * Alignment::getDeviceName ( )

inline

Definition at line 455 of file scopesim_helper.h.

id()

double Alignment::id ( )

inline

Definition at line 464 of file scopesim_helper.h.

ih()

double Alignment::ih ( )

inline

Definition at line 460 of file scopesim_helper.h.

instrumentHaDecToMount()

void Alignment::instrumentHaDecToMount	(	Angle	instrumentHa,
		Angle	instrumentDec,
		Angle *	primary,
		Angle *	secondary
	)

Definition at line 337 of file scopesim_helper.cpp.

instrumentToObserved()

void Alignment::instrumentToObserved	(	Angle	instrumentHa,
		Angle	instrumentDec,
		Angle *	observedHa,
		Angle *	observedDec
	)

Definition at line 417 of file scopesim_helper.cpp.

lst()

Angle Alignment::lst

(

)

Definition at line 233 of file scopesim_helper.cpp.

ma()

double Alignment::ma ( )

inline

Definition at line 476 of file scopesim_helper.h.

me()

double Alignment::me ( )

inline

Definition at line 480 of file scopesim_helper.h.

mountToApparentHaDec()

void Alignment::mountToApparentHaDec	(	Angle	primary,
		Angle	secondary,
		Angle *	apparentHa,
		Angle *	apparentDec
	)

mountToApparentHaDec: convert mount position to apparent Ha, Dec

Parameters

primary
secondary
apparentHa
apparentDec

Definition at line 238 of file scopesim_helper.cpp.

mountToApparentRaDec()

void Alignment::mountToApparentRaDec	(	Angle	primary,
		Angle	secondary,
		Angle *	apparentRa,
		Angle *	apparentDec
	)

mountToApparentRaDec: convert mount position to apparent Ra, Dec

Parameters

primary
secondary
apparentRa
apparentDec

Definition at line 288 of file scopesim_helper.cpp.

mountToInstrumentHaDec()

void Alignment::mountToInstrumentHaDec	(	Angle	primary,
		Angle	secondary,
		Angle *	instrumentHa,
		Angle *	instrumentDec
	)

mountToInstrumentHaDec: convert mount axis positions to instrument (encoder) HA/Dec without applying the Wallace pointing-model corrections.

Definition at line 297 of file scopesim_helper.cpp.

np()

double Alignment::np ( )

inline

Definition at line 468 of file scopesim_helper.h.

observedToInstrument()

void Alignment::observedToInstrument	(	Angle	observedHa,
		Angle	observedDec,
		Angle *	instrumentHa,
		Angle *	instrumentDec
	)

Definition at line 445 of file scopesim_helper.cpp.

setCorrections() [1/2]

void Alignment::setCorrections ( double *  coeffs )

inline

Definition at line 444 of file scopesim_helper.h.

setCorrections() [2/2]

void Alignment::setCorrections	(	double	ih,
		double	id,
		double	ch,
		double	np,
		double	ma,
		double	me
	)

setCorrections set the values of the six corrections

Parameters

ih
id
ch
np
ma
me

Definition at line 561 of file scopesim_helper.cpp.

setFlipHourAngle()

void Alignment::setFlipHourAngle ( double  deg )

inline

Definition at line 449 of file scopesim_helper.h.

Member Data Documentation

latitude

Angle Alignment::latitude = 0

Definition at line 416 of file scopesim_helper.h.

longitude

Angle Alignment::longitude = 0

Definition at line 417 of file scopesim_helper.h.

mountType

MOUNT_TYPE Alignment::mountType = EQ_FORK

Definition at line 419 of file scopesim_helper.h.

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The documentation for this class was generated from the following files:

• scopesim_helper.h
• scopesim_helper.cpp