Definition of a FITS table providing the transformation between photometric systems.
The table is created by munipack phfotran action and used by phcal action.
This specification has been developed for internal use in Munipack and backward compatibility is not guarantied.
The file has first HDU dummy without any machine-readable information and just a short description and reference in comments.
| HDU | EXTNAME | Description |
|---|---|---|
| 0 | Dummy | |
| 1 | FOTRAN | The transformation table |
The second HDU is a table with the transformation matrix. EXTNAME is set to FOTRAN. The header contains identifiers of input (instrumental) and output (standard) photometry systems in keywords PHOTSYS1 and PHOTSYS2. Amount of both columns and rows will generally variable and non-equal.
| Keyword | Value | Description |
|---|---|---|
| EXTNAME | FOTRAN | mandatory extension identifier |
| PHOTSYS1 | instrumental photometry system | |
| PHOTSYS2 | standard photometry system | |
| FILTERi | i-th standard filter |
Columns of the table are named as instrumental filters. Rows are equivalent filters. Lets elements of tables are Ci,j than the values in the standard system (PHOTSYS2) are derived from the instrumental system (PHOTSYS1) as
c'i = Σj Cij cj
where i,j = { B,V ...} points on all available filters.
| Column | Type | Description |
|---|---|---|
| FILTER | 12A | Filter designation |
| Ci1 | D | a coefficient |
| Ci2 | D | a coefficient |
| .. | D | a coefficient |
| Cij | D | a coefficient |
| .. | D | a coefficient |
| CiN | D | a coefficient |
The table can be created by hand, but the structure must be respected and all identifiers included.