Re: Photometry in VO Spectrum Model

From: Tim Jenness <t.jenness-at-jach.hawaii.edu>
Date: Mon, 23 Oct 2006 09:31:40 -1000 (HST)


On Mon, 23 Oct 2006, Anita Richards wrote:

>
>
> On Mon, 23 Oct 2006, Doug Tody wrote:
>>
>> I can see that one might want to plot a spectrum in magnitude units in
>> a standard system. A good question to consider however, is whether this
>> feature belongs in the user interface, where the spectrum is plotted in
>> whatever units the user prefers, or in the protocol. This is similar to
>> displaying RA/DEC in sexagesimal units, while we use decimal degrees in
>> the protocol. This sort of conversion is easily handled in the user
>> interface.
>>
>
> Unfortunately it is not easy, that is the problem. At least, I am assured by
> optical astronomers that for highly accurate conversion you need a raft of
> metadata and even to know the nature of the object. That is also the case
> for converting X-ray counts to physical units.

and antenna temperature in all its many forms (TA*, TR* etc) where people can't even agree on a standard nomenclature for all the efficiency terms that need to be known to convert kelvin to Jy.

-- 
Tim Jenness
James Clerk Maxwell Telescope
Received on 2006-10-23Z21:32:59