search

ratt-ru / simms

Creates empty measurement sets using the the CASA simulate tool.
GNU General Public License v2.0
7 stars 8 forks source link

-date parameter handling error #24

Closed TariqBlecher closed 7 years ago

TariqBlecher commented 8 years ago

So I run

simms -T VLBA -t casa -n timetest2.MS -dec 0.216265686869rad -ra 3.27608481687rad -st 2 -dt 100 -f0 87GHz -df 1GHz -stl -el 0.17 vlba_antenna/ -date 2013/06/04/00:20:22

and in the output there is the line

015-11-15 19:36:35 INFO NewMSSimulator::observe()+ Full time range: 04-Jun-2013/10:42:55.0 -- 04-Jun-2013/12:42:55.0 TAI with int = 100

The incorrect time is also written in the MS column TIME.

rdeane commented 7 years ago

This bug still seems to be there I'm afraid.

simms -T VLBA -t casa -n SgrA40muas.MS -dec -29.007810556deg -ra 266.416837083deg -st 24.000000 -sl 24.000000 -slg 0.000000 -dt 10 -f0 228.000000GHz -df 0.250000GHz -nc 16 -date UTC,2017/04/01/00:00:00.00 ../input/EHT_ANTENNAtable

results in an MS with date/time start time of 31-Mar-2017/15:31:06.6 (UTC), as reported by CASA v4.7.

rdeane commented 7 years ago

something very strange going on here, check out the attached table. Using simms, I've simulated 8 MSs in 3 hour increments, starting at 2017/04/01/00:00:00.

Using the listobs task (CASA v4.7), I grab the date time info which is listed in the second column. Does this give an additional clue as to the problem here?

screen shot 2017-02-21 at 9 39 20 am

SpheMakh commented 7 years ago

I think something is going wrong with the way I'm parsing the date to CASA simulator.

SpheMakh commented 7 years ago

Fixed in the release (0.9.4). Update (pip install simms --upgrade) and it should simulate the observation at the specified time instead of trying to start the observation at transit.

rdeane commented 7 years ago

Great, all seems to be working. Out of interest, why does CASA arbitrarily add an extra 37 seconds to the start time? I tried it for a start time in April 2017 and July 2017, and both start 37 seconds later than specified. Just curious...

SpheMakh commented 7 years ago

I was wondering about the same thing. I'll play around with this a bit more, and maybe I can figure it out.

TariqBlecher commented 7 years ago

It might be to do with leap seconds which I think are mild calendar alterations between TAI and UTC.. But just guessing On Mon, 27 Feb 2017 at 11:09 Sphesihle Makhathini notifications@github.com wrote:

I was wondering about the same thing. I'll play around with this a bit more, and maybe I can figure it out.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/radio-astro/simms/issues/24#issuecomment-282664954, or mute the thread https://github.com/notifications/unsubscribe-auth/AJoWXY4Rzl2f8lG9l7clWpyYyFPfwG3sks5rgpKzgaJpZM4Gimak .