Dithers missing or masked for tile_id=1027985

[gblancm]

tile_id=1027985 is an important tile, right at the kinematic center of the LMC, inspecting it in LVM-vis it looks like it is missing dithers, or some dithers are masked

[ivan-katkov]

I am thinking about regenerating the HiPS images while rejecting outlying exposures. That should remove the artifacts in the HiPS images. During this process, I can compile a list of bad tiles that need to be reviewed to understand the issues in them.

[gblancm]

I think that would be super valuable on both fronts. That's a great idea Ivan, thanks!

…

On Thu, Apr 10, 2025 at 11:19 AM Ivan Katkov ***@***.***> wrote: I am thinking about regenerating the HiPS images while rejecting outlying exposures. That should remove the artifacts in the HiPS images. During this process, I can compile a list of bad tiles that need to be reviewed to understand the issues in them. — Reply to this email directly, view it on GitHub <#202 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AIOKNYYHQYOPIRDYRE7H4RT2YYZSPAVCNFSM6AAAAABXCNCPYKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJSGEYDQNZQGU> . You are receiving this because you authored the thread.Message ID: ***@***.***> *ivan-katkov* left a comment (sdss/lvmdrp#202) <#202 (comment)> I am thinking about regenerating the HiPS images while rejecting outlying exposures. That should remove the artifacts in the HiPS images. During this process, I can compile a list of bad tiles that need to be reviewed to understand the issues in them. — Reply to this email directly, view it on GitHub <#202 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AIOKNYYHQYOPIRDYRE7H4RT2YYZSPAVCNFSM6AAAAABXCNCPYKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJSGEYDQNZQGU> . You are receiving this because you authored the thread.Message ID: ***@***.***>

--

------------------------------------------------------------------ Guillermo A. Blanc Associate Director of Strategic Initiatives Observatories of the Carnegie Institution for Science and Las Campanas Observatory (LCO) 813 Santa Barbara St, Pasadena, CA, 91101, USA ***@***.*** ***@***.***>

------------------------------------------------------------------ *I believe in the importance of personal time. I do not expect a response to this email outside of your normal working hours.* *Creo en la importancia del tiempo personal. No espero una respuesta a este correo fuera de su horario laboral normal.*

[ivan-katkov]

To compile a list of exposures with likely incorrect flux calibration, which should be ignored for HiPS generation, I filtered them out using the median values of FLUX + SKY (SFrame).

The histogram of these values:

I filtered out 160 exposures using the condition median_fluxsky'] > 1e-10. The full list of exposure numbers is:

3481 3482 3483 3484 3616 3683 3684 3805 3806 3807 3808 3810 3811 3877 3925 3926 4426 4427 4435 4436 4437 4553 4554 6695 6816 7355 7395 7529 7530 8289 8290 8315 8318 8374 8673 8674 9176 10750 13697 14959 14967 15359 15638 15639 15640 15754 17220 19476 19940 19941 19943 19944 19948 20013 20014 20015 20018 20184 20300 20940 21144 21288 21414 21638 21691 21692 21693 21694 21695 21696 21697 21698 21699 21958 21959 22084 22085 22092 22158 22226 22227 22229 22231 22232 22233 22310 22312 22314 22316 22317 22356 22358 22917 23072 23083 23144 23287 23473 23815 23887 23888 23897 23953 23958 23959 23962 23963 24117 24198 24204 24205 24206 24207 24208 24209 24210 24211 24212 24213 24284 24285 24491 24495 24706 24755 24991 24995 25207 25271 25341 25343 25344 25946 25948 25961 26128 26229 26362 26363 26364 26365 26430 26624 26625 26809 27354 27424 27486 28133 28562 28566 28883 28955 28991 29358 29566 30296 30477 30503 30519

You can also verify the spectra in lvmvis:

https://data.sdss5.org/lvmvis/?q=expnum+in+(3481,3482,3483,3484,3616,3683,3684,3805,3806,3807,3808,3810,3811,3877,3925,3926,4426,4427,4435,4436,4437,4553,4554,6695,6816,7355,7395,7529,7530,8289,8290,8315,8318,8374,8673,8674,9176,10750,13697,14959,14967,15359,15638,15639,15640,15754,17220,19476,19940,19941,19943,19944,19948,20013,20014,20015,20018,20184,20300,20940,21144,21288,21414,21638,21691,21692,21693,21694,21695,21696,21697,21698,21699,21958,21959,22084,22085,22092,22158,22226,22227,22229,22231,22232,22233,22310,22312,22314,22316,22317,22356,22358,22917,23072,23083,23144,23287,23473,23815,23887,23888,23897,23953,23958,23959,23962,23963,24117,24198,24204,24205,24206,24207,24208,24209,24210,24211,24212,24213,24284,24285,24491,24495,24706,24755,24991,24995,25207,25271,25341,25343,25344,25946,25948,25961,26128,26229,26362,26363,26364,26365,26430,26624,26625,26809,27354,27424,27486,28133,28562,28566,28883,28955,28991,29358,29566,30296,30477,30503,30519)