[daip] Re: DELZN questions

[Leonia Kogan]

George,

The following is another comment to your request 3a
 
  a. Why not do the plots in time units, since this will make comparison
     with plots of the input MBDs easier?

First of all it is not soi simple to compare the value on the plot with 
the value of the MBD at CL table,
because DELZN does not plot directely MBD of the SN table. See the 
DELZN's explain .
Second,  DELZN plots are labeled at the part of days.
Using PRTAB to print out the SN table you can type DOHMS=0 and the time 
will be printed out at the part of the day also.

Leonia



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?)
>
> 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.)
>
> 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?
>
>   b. Why not have an option (e.g., APARM(1)=3) to create all 3 types of
>      plots in a single run?
>
>   c. Why not have an option to plot the residuals corresponding to
>      each type of current plot?
>
>   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.)
>
>   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.
>
> 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