wcs.ps and scs.ps

[Arnold Rots]

Eric Greisen wrote:
> Michael Nolan writes:
>  > Comments on the wcs paper (1999 April 9 version):
>  > 
>  > In table 4, adu means A/D converter.  Do you mean converter (as in
>  > physical device), or do you mean DN?  I can see a value in both, and
>  > have a specific need for the former, since we have four parallel IF
>  > chains simultaneously sampled.
> 
>     I am also unfamiliar with these units.  Can Francois or one of the
> units gurus at OGIP comment on this?

adu is the (pseudo-)unit of the raw numbers as they come out of the
A/D converter device - to be transformed into energy.
In HEA, it typically (but nor exclusively) refers to the output of A/D
converters that process CCD read-outs,

  - Arnold

> 
> 
> Eric W. Greisen

--------------------------------------------------------------------------
Arnold H. Rots                                         AXAF Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 81                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head-cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
--------------------------------------------------------------------------