BSM_South transformation coefficients

Thu, 08/18/2016 - 11:56

Here are the transformation coefficients for BSM_S (BSM South) for 2016, using 5 photometric nights and Landolt standards near the beginning of the year.

Tb_bv = 0.0817

Tv_bv = 0.0102

Tr_vi = 0.0061

Ti_vi = -0.0382

Tbv = 0.9970

Tvi = 1.0387


American Association of Variable Star Observers (AAVSO)
BSM_S transform error values

What is the error value for these coefficients?


transform error values

Hi George,

Here are the errors.

Tb_bv = 0.0817 +/- 0.0281

Tv_bv = 0.0102 +/- 0.0081

Tr_vi = 0.0061 +/- 0.0071

Ti_vi = -0.0382 +/- 0.0130

Tbv = 0.9970 +/- 0.0374

Tvi = 1.0387 +/- 0.0077


American Association of Variable Star Observers (AAVSO)
Updated BSM_S Transformation Coeffs 190217

BSM_S transformation coefficients were updated on 190217 using NGC1252 images taken on 181014. The VPhot coeffs have also been updated.

description= TG - Version TG_V7.3 beta 5, Telescope= BSM_S, Time created (UT) = 2019_02_18_00:56:49
Tbv= 1.014
Tb_bv= 0.005
Tv_bv= -0.008
Tvr= 0.977
Tv_vr= -0.011
Tr_vr= 0.042
Tri= 1.017
Tr_ri= 0.049
Ti_ri= 0.012
Tvi= 0.992
Tv_vi= -0.004
Ti_vi= 0.005
Tr_vi= 0.015
Tbv= 0.022
Tb_bv= 0.012
Tv_bv= 0.010
Tvr= 0.027
Tv_vr= 0.019
Tr_vr= 0.016
Tri= 0.043
Tr_ri= 0.017
Ti_ri= 0.021
Tvi= 0.019
Tv_vi= 0.010
Ti_vi= 0.010
Tr_vi= 0.012
[R Squared Values]
Tbv= 0.985
Tb_bv= 0.007
Tv_bv= 0.022
Tvr= 0.976
Tv_vr= 0.010
Tr_vr= 0.182
Tri= 0.951
Tr_ri= 0.221
Ti_ri= 0.011
Tvi= 0.989
Tv_vi= 0.005
Ti_vi= 0.007
Tr_vi= 0.043

American Association of Variable Star Observers (AAVSO)
TA ini file

Yes, that is why I have been attaching this file recently. If you have some recent images you may want to use this ini for all, but that may be annoying?? Up to you.


American Association of Variable Star Observers (AAVSO)
Feedback for BSM_S


Thanks for the latest (July 2020) BSM_S transforms.  I've  reduced most of the BSM_S images that have been waiting for transforms.  ...just a couple more nights remain.  I'm very happy to be back on Berry for the GU Sgr and ASAS-RCB-8 projects.

BSM_S worked well in most regards, and it kept the data flowing while Berry was down.  I was happy to have it.   There is one problem that decreases the efficiency of BSM_S, at least for my targets: tracking.

I don't think I'm particularly picky about tracking.  For 30s exposures BSM_S does fine.  For 60s exposures there are tracking problems, but most of the images are still usable.  For 80s exposures, I couldn't use (stack) about ~40% of the images.  Either the tracking was just too bad, or the images didn't solve (probably because of poor tracking).


BSM_S tracking

Hi Phil,

The CGEM is supposed to be ok at the 60-80second range, but this one is getting old.  Poor tracking is one of the big reasons that we are upgrading all BSMs to Paramount ME mounts (except for BSM_TX, which already has a MyT).  With the ME and the largish pixels of the BSMs, we should be able to do 300second exposures without noticeable elongation.  With the E180 OTAs, exposures will be ~6x shorter as well.

Be a little careful with BSM_Berry.  If you look at the flats, they look terrible.  So far, things flatten pretty well as the pattern seems stable, but I'll be happy when we can switch over to the CMOS camera.


American Association of Variable Star Observers (AAVSO)
FY Lib Problems

Problem 1 (may not be a problem): Report shows tiny measuring apertures on the target (first image on the attachment. This may simply be a visualization artifact. The analysis was set for 1.5xFWHM.

Problem 2: All images I checked received from BSM-S and BSM_S2 fail to recognize FY Lib (note small red circle in second image on the attachment) but does recognize the check and comp. Also, there appears to be no transformation coefficients. These images are piling up in my account. Should I simply delete them as unanalyzable?


American Association of Variable Star Observers (AAVSO)
Problem 2


I've had similar problems, but this looks to be a bit more difficult.  If you share with me one of the images and the saved sequence you use for this star, I'd like to see if I can fix it.



American Association of Variable Star Observers (AAVSO)
Re-created Sequence

We got it straightened out two days ago. Deleted sequence and created it again. Found the target.


American Association of Variable Star Observers (AAVSO)
unfound targets question


This seems to happen fairly often.  You and I use the same work-around, but I don't understand why enlarging the "search radius" doesn't seem to work.  That would be a lot quicker.  Have you tried that?  Has enlarging the search radius ever worked for you?