Conventions

• All angles or coordinates are stored internally in radians
• All angles or coordinates mostly are presented to the user in degrees (sexagesimal format for stars)
• double must be used as storage

Use cases

Observability of a source (or list of sources) for a given interferometer

Inputs	User format	internal format
Star coordinate	anything valid (name or any std coords)	RAJ2000,DEJ2000
Observing site location	selection of one supported observatory	observatory reference
Date of observation ( or period of time )	like DDMMYYYYHHMM	(Modified) Julian Day ( precise up to the second )

Plot outputs: TODO : How to represent the observability of a list of star onto multi-telescope

Is the source visible in the sky ?

Is the source over the horizon ?

outputs	Internal/User	Format
celestial coordinates	Internal	HA / delta ?? units TBC TBD
over the horizon	User	boolean

What is the AirMass value ?

Inputs	User format	internal format
Seeing	choice or value ?	TBD
Humidity / Temperature...	choice or value ?	TBD

outputs	Internal/User	Format
AirMass	User	double

What is the best method to get the airmass value?

Where are the sun / moon ?

Inputs	User format	internal format
twilight constraints	angle degrees GM: est-ce que ASTRO/NAVAL/CIVIL sont des valeurs discrites qui parlent ?	double radians

outputs	Internal/User	Format
sunrise sunset moonrise moonset	User	DateTime couples

Est-ce qu'il faut gerer d'autre planetes sources lumineuses ??? Quelles doit etre la precision pour les ephemerides?

Is the star still visible given to a shadowing ???

Inputs	User format	internal format
environment shadowing ( telescopes, mountains, building ....)	angle d'obstruction ( de 0 a 90 degres) en fonction de l'azimuth (repere a definir)	couples of Altitude / Azimuth points ( pointer ver la specification (a faire) )
telescope(s) min elevation	angle degree	angle radians

outputs	Internal/User	Format

What is the formulae of the observability given to the whole previous results?

A-t'on besoin de calculer l'AirMass par station? Est-ce que la voute celeste est la meme pour toutes les stations a un meme moment?

S'arrete-ton des le premier critere mauvais ou doit on faire un bilan de pertes...( par ex: une mauvaise airmass compensee par un configuration optique avec moins de pertes)

Comment gere-t'on l'observalité d'une liste d'etoiles? Est simplement la juxtaposition des resultats independants ou y-a t'il des contraintes de gestion par groupe?

Modelling of a source from a given interferometer

TBD

Various informations

Station Coordinates

The software handles station coordinates as described in the OIFITS (see OI_ARRAY table description).

VLTI configuration

Eso defines the coordinates in an propriatary maner. The right way to get the right informations is to read the data from an AMBER oifits ( may be generated by ASPRO ).

CHARA configuration

Chara expresses the station coordinates in the same format as OIFITS : TBD find URL

Java astronomy libraries

JSkyCalc = Java version of skycalc
AstroLib URLToBeDefined)?topicparent=Jmmc/Software.JmmcAsproProjectConception;nowysiwyg=0" rel="nofollow" title="PAL projet astrogrid (utilisé par APES et topcat) (this topic does not yet exist; you can create it)">PAL projet astrogrid (utilisé par APES et topcat)

Verifier : conversion coordonnees et ephemerid (au moins soleil et lune)

Various libraries

• http://jas.freehep.org/jas3/