[daip] DTSUM and DiFX data

[Walter Brisken]

Great to hear that.  Thanks!

-W

On Sat, 23 May 2009, Eric Greisen wrote:

> Walter Brisken wrote:
>>  DiFX, the new software correlator that is to replace the VLBA correlator
>>  in the next few months, can produce data with integration times that are
>>  not restricted to be multiples of 131072 microseconds.
>>
>>  DTSUM seems to assume that it is an exact multiple of this:
>>
>>  Data integration time (cross-power) =  2.000000 =   15 * 0.131072 seconds
>>  Data integration time (total-power) =  2.000000 =   15 * 0.131072 seconds
>>
>>  I'm not sure if displaying the "=   15 * 0.131072" is for information only
>>  or if internally it (or any other VLBI AIPS task) makes any assumption
>>  about the granularity of integration times in actual calculations.  I hope
>>  not!
>> 
>
> The 131072 number occurs 2 places in AIPS - this display function in DTSUM 
> which I think was part of the vlbi simulator set that Athol began but never 
> finished (DTSIM, DTCHK).  It also occurs in KRING as the default for CPARM(1) 
> a global integration time (16 * 0.131072).  It has no specific use in other 
> words.
>
> Eric Greisen
>