[daip] DELZN questions

[Leonia Kogan]

George,

I have put the modified version of DELZN yesterday. It is available this 
morning from 'tst' AIPS version.

Look the following comments to your suggestions:

George Moellenbrock wrote:

>
> Hi Leonia-
>
> A couple of quick questions about DELZN:
>
> 1. What are the units of the "SQRT of variance of the residuals"
> that is reported at the end of execution (for PRTLEV=2)?  I assume
> it is in millimeters, but the value reported seems rather larger than
> the rms implied by the data in the plots.  In fact, it looks like
> a plausible estimate of the rms from the plots is something like
> the sqrt of the value reported.  (Has the sqrt of the variance
> actually been taken?)


You are right. This has been fixed

>
> 2. Why does DELZN insist on writing a txt file at more than just the 
> single reference timestamp used in the solution?  My CL table has a 
> large number of entries, and DELZN fails complaining about more than 
> 10000 rows. I need both to update my CL table and create the txt file 
> because I have to use the solution in the original dataset, and 
> transfer it to another dataset.  But I am forced to turn off the CL 
> update to get a txt file. It seems to me that a single set of 
> coefficients per antenna---i.e., those reported during execution--- is 
> all that is really required in the txt file.  (This makes the txt file 
> more useful in record-keeping and
> external analysis, too.)


Number of rows at the output file increased to 100000

>
> 3. A couple of suggestions:
>
>   a. Why not do the plots in time units, since this will make comparison
>      with plots of the input MBDs easier?

I have not done it because it may contradict with other people who 
prefer milimeters!

>
>   b. Why not have an option (e.g., APARM(1)=3) to create all 3 types of
>      plots in a single run?

I have not done it. I do not think it is required. As I remember you 
agree with me.

>
>   c. Why not have an option to plot the residuals corresponding to
>      each type of current plot?

It has be done under control of APARM(9)

>
>   d. Why not have APARM(2)=0 force no atm solution (clock only)?  (This
>      would be useful for diagnostic purposes when trying to decide
>      what orders to use for atm and clock.)

It's done

>
>   e. It would be good to have a REFANT parameter that would be used
>      to force the solution to use only input MBDs that share the 
> specified
>      reference antenna.  I have found that just a few MBDs with a
>      different ref ant can yield DELZN solutions differing wildly from
>      what you get with a consistent refant.  It took me awhile to 
> discover
>      that I had a few MBDs with differing refant lurking in my input
>      SN table, and things improved tremendously when I avoided them.
>      In any case, DELZN should complain in this case that it is using
>      solutions with differing refants.

You are agrre that is not required

>
> I am really finding DELZN an interesting task.  With data carefully 
> observed to provide good leverage to separate the clock and the atm, I
> think I am getting very good zenith delay solutions.


:)

>
> Thanks,
> George


Thank you George for the valuable comments

Leonia