Re: [TASS] photometric vs. non-photometric

[Herbert R Johnson <hjohnson@PLUTO.NJCC.COM>]

On         Thu, 9 Sep 1999 00:22:18 GMT, Andrew Bennett <andrew.bennett@NS.SYMPATICO.CA> wrote:
*>On Tue, 7 Sep 1999 10:08:41 -0400, Herbert R Johnson
*><hjohnson@pluto.njcc.com> wrote:
*>
*>>... My impression from your original question was that you were interested
*>>in an explanation for why some "surveyed" parts of the sky did not make
*>>"the TASS catalog". As you've stated the problem here, you propose defining
*>>a section of the sky, asking for ALL the images taken and processed of
*>>that section, and then somehow "comparing" those images and processed
*>>data to the corresponding section of the TASS "catalog" to see what was
*>>missed.
*>>
*>>I've put a number of words in quotation marks, because I think the issues
*>>are not quite as you have implied in your proposed methods.
*>
*>What I actually wrote, following on a remark of yours:

First, my apologies: I did not intend to imply that I was quoting YOUR WORDS
when I used the above quotation marks; I was trying to emphasise that your
questions depended on the meaning of the words I put in quotation marks.
Sorry that flat-text email lacks underscores or italics, but I thought I
was clear that this was about impressions, those words were emphasised
but not your quotes.

*>No, I don't intend to write a dissertation on the quoted
*>words and phrases, particularly as they are "quoted" only
*>in the sense that they have "" round them. Instead, I will expand
*>on what I meant by:
*>
*>>A lot of the gaps in tenxcat are like this

..and so you did.

Well. I had two points. One, the issue is not just about raw data, it
is also about the process of analysis that contributed to the apparent
scarcity of observations in the database.
Two, my own experiences in asking these sort of questions led ME to
review the process of Mark III data reduction, which led me to my recent
Tech Note on the Mark III software and data process. So I provided some
background as a result of that work, and suggested a more specific
question would be a good idea. Apparently it was, you re-posed the question,
and some answers are appearing. As for the length of my reply, well
chalk that up to the problem of a quick but complete reply in real
time email.

*>But my personal opinion is that the scatter in the
*>number of accepted magnitude determinations is too
*>great and extends to sources which are too bright
*>to be accounted for by variations in seeing. If
*>you can think of a way to check on this without
*>going to the original images, please tell us.
*>
*>Andrew Bennett

I'll leave it to my colleages who are doing the work to respond in
detail. Again, I suggested you consider the methods
before requesting the data, as that seems to me to be a reasonable
course of action. I did not say it was unnecessary to look at the original
images, at worst I said it was untimely.

Also, please note: I don't speak for TASS, no one does. I am speaking
to the issues behind your previous and current question, because I've
seen those issues before. I have tried to gather some of these issues
into some Tech Notes for persons like yourself with these kinds of
questions.

Herb JOhnson

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