[Difx-users] Question - correlate near field sources ie Spacecraft

Thu Feb 27 01:29:26 EST 2020

Hi Stuart, 

in case of VDIF files you need to run 

vsum -s /raid0/etransfer/wa/* > filelist.wa (no need to specify the format) 

Cheers, 

Simone 

Am 2020-02-27 04:05, schrieb Stuart Weston via Difx-users:

> Well two of you asked for updates �� Progress so far ... 
> 
> DIRECTORY2FILELIST: 
> 
> First issue, directory2filelist doesn't like VDIF files (Which I have for Wa and Ti) : 
> 
> oper at ww-flexbuf-01 DiFX-2.5.2 vygr2> directory2filelist /raid0/etransfer/wa/vygr2_wa_no0108 VDIF_8000-128-2-2 
> 
> VDIF Warning: Changing frameheadersize from 32 to 16 
> 
> VDIF Warning: Changing databytesperpacket from 8000 to 124473216 
> 
> Segmentation fault 
> 
> It is even more unhappy with "vbs_fs" for merging jive5ab vdif chunks into one logical file at the fuse mount point (PS: I now use "vbs_fs" for DSPSR with Williem for VDIF Single Dish pulsar data). 
> 
> V2D : 
> 
> Also for v2d ephemFile has to be either tle (Two-Line elements) or bsp (which I assume means BaryCenter on 399 Earth, our observing platform). Now NASA HORIZONS doesn't seem to produce a valid file acceptable to SPICE. So goto NASA NAIF which has some "old" archived bsp files but nothing current. 
> 
> I was trying to use the HORIZONS ID "Voyager_2" , that didn't work : 
> 
> ================================================================================ 
> 
> Toolkit version: N0066 
> 
> SPICE(IDCODENOTFOUND) -- 
> 
> The target, 'Voyager_2', is not a recognized name for an ephemeris object. The 
> 
> cause of this problem may be that you need an updated version of the SPICE 
> 
> Toolkit. Alternatively you may call SPKEZ directly if you know the SPICE ID 
> 
> codes for both 'Voyager_2' and '399' 
> 
> A traceback follows.  The name of the highest level module is first. 
> 
> spkezr_c --> SPKEZR 
> 
> Oh, by the way:  The SPICELIB error handling actions are USER-TAILORABLE.  You 
> 
> can choose whether the Toolkit aborts or continues when errors occur, which 
> 
> error messages to output, and where to send the output.  Please read the ERROR 
> 
> "Required Reading" file, or see the routines ERRACT, ERRDEV, and ERRPRT.
> 
> Anyway under the NAIF archive there is a "voyager_2.ST+1992_m05208u.merged.bsp" which goes to "2021 JAN05". Now you need NAIF ID 3 for the Earth Barycenter (our observation platform) and NAIF ID -32 for Voyager 2 
> 
> SOURCE VGR2 { 
> 
> ephemObject = -32 
> 
> ephemFile   = voyager_2.ST+1992_m05208u.merged.bsp 
> 
> } 
> 
> Now v2d works, there are some warnings about stop/start times for the vdif files. 
> 
> oper at ww-flexbuf-01 DiFX-2.5.2 vygr2> vex2difx --force vygr2.v2d 
> 
> Warning: Filelist file vygr_atca.filelist was a listing with no start/stop times. 
> 
> Note: Future versions of vex2difx may stop allowing file lists without start/stop times.  Filelists for VDIF and Mark5B files with start/stop times can be generated with "vsum -s" and "m5bsum -s" respectively.  These times allow vex2difx to properly assign data to jobs and is especially important in cases where multiple jobs are generated per project. 
> 
> Warning: Filelist file vygr_dss.filelist was a listing with no start/stop times. 
> 
> Warning: Filelist file vygr_wa.filelist was a listing with no start/stop times. 
> 
> start date: 2020y015d08h00m00s 
> 
> stop date: 2020y015d12h00m00s 
> 
> Warning: no clock values for antenna AT . 
> 
> Warning: no clock values for antenna WA . 
> 
> Warning: no clock values for antenna TI . 
> 
> Note: Proceeding even though there were 3 warnings. 
> 
> Warning: Job vygr2 1: no clock offsets being applied to antenna AT 
> 
> Unless this is intentional, your results will suffer! 
> 
> Warning: Job vygr2 1: no clock offsets being applied to antenna TI 
> 
> Unless this is intentional, your results will suffer! 
> 
> Warning: Job vygr2 1: no clock offsets being applied to antenna WA 
> 
> Unless this is intentional, your results will suffer! 
> 
> Warning: Job vygr2 2: no clock offsets being applied to antenna AT 
> 
> Unless this is intentional, your results will suffer! 
> 
> Warning: Job vygr2 2: no clock offsets being applied to antenna TI 
> 
> Unless this is intentional, your results will suffer! 
> 
> Warning: Job vygr2 2: no clock offsets being applied to antenna WA 
> 
> Unless this is intentional, your results will suffer! 
> 
> 2 job(s) created. 
> 
> I'll come back to the CLOCK OFFSETS next as I do have those to add, I'll append a $CLOCK section shortly. 
> 
> I am just working my way through step by step, where each step will have several iterations to sort things out. 
> 
> Stuart Weston 
> 
> Mobile: 021 713062
> 
> Skype: stuart.d.weston
> Email:  stuart.weston at aut.ac.nz
> 
> http://www.atnf.csiro.au/people/Stuart.Weston/index.html
> 
> Software Engineer
> Institute for Radio Astronomy & Space Research (IRASR)
> School of Engineering, Computer and Mathematical Sciences
> Faculty of Design and Creative Technologies
> Auckland University of Technology, New Zealand.
> 
> http://www.irasr.aut.ac.nz/ 
> 
> FROM: Stuart Weston 
> SENT: Thursday, 27 February 2020 1:51 PM
> TO: difx-users at listmgr.nrao.edu
> CC: Oleg Titov <Oleg.Titov at ga.gov.au>
> SUBJECT: Question - correlate near field sources ie Spacecraft 
> 
> I have some VLBI on Voyager to correlate. 
> 
> So had a read of : 
> 
> https://www.atnf.csiro.au/vlbi/dokuwiki/doku.php/difx/spacecraft 
> 
> I have setup SPICE 
> 
> Anyone done this before and any tip's, help or suggestions ? 
> 
> The ephemFile as that as obtained say from https://ssd.jpl.nasa.gov/horizons.cgi [1] ? 
> 
> Stuart Weston 
> 
> Mobile: 021 713062
> 
> Skype: stuart.d.weston
> Email:  stuart.weston at aut.ac.nz
> 
> http://www.atnf.csiro.au/people/Stuart.Weston/index.html
> 
> Software Engineer
> Institute for Radio Astronomy & Space Research (IRASR)
> School of Engineering, Computer and Mathematical Sciences
> Faculty of Design and Creative Technologies
> Auckland University of Technology, New Zealand.
> 
> http://www.irasr.aut.ac.nz/ 
> 
> _______________________________________________
> Difx-users mailing list
> Difx-users at listmgr.nrao.edu
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-- 
Dr. Simone Bernhart
Reichert GmbH / Bundesamt für Kartographie und Geodäsie
c/o VLBI Korrelator
Max-Planck-Institut für Radioastronomie
Auf dem Hügel 69
53121 Bonn
GERMANY
phone: +49 228 525 479
fax:   +49 228 525 229
email: simone at mpifr-bonn.mpg.de 

Links:
------
[1] https://ssd.jpl.nasa.gov/horizons.cgi
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