SMA Quick Links
DR home
Convert format
Using CASA
Tutorials
FAQs

Updating SMA Baselines


All data directories contain an 'antennas' file which lists the positions of the antennas in the array; these positions are used to derive the baseline information. After a configuration change, a baseline track is run to determine the new positions of the antennas. These new, correct positions are applied to future science tracks, but earlier tracks (after the antenna moves but before a successful baseline track) are not corrected. This must be done by hand during data reduction.

Often, achieving a good solution to the antenna positions may take a few days or even weeks if the weather is poor. In many cases data has been taken with a reasonable solution, but would benefit from using an even better fit.

See the effects of a poor baseline solution here.

If you have any questions or concerns just email smarequester@cfa.harvard.edu.

To implement these changes, see the MIR Cookbook (sec. 6.4) or the MIRIAD User's Manual (task:uvedit).

NEW - The table below lists data sets which require a baseline solution following antenna moves. However, at later dates further baseline tracks are usually taken to refine these solutions. You can find a comprehsive list of all the baseline solutions at Complete List of SMA Antennas Files. This list can be checked to see if revised antenna positions exist for your data set. Remember to confirm that the antennas are still on the same pads. The values are positions given in meters and the adjustments are tiny; you should expect the new value to be only micrometers from your existing value.


2024
Configuration New antenna file Track range to update
Compact 240426_10:20:40 240419_14:32:37 - 240425_15:23:17
Compact 240418_15:10:00 240418_04:44:24
Extended 240128_05:29:49 240125_12:34:39 - 240126_12:31:36
Extended 240128_05:29:49_not5 240124_13:20:11 - 240124_13:26:19

2023
Configuration New antenna file Track range to update
Compact 231109_02:20:01 231104_03:58:54 -231107_04:00:37
Extended 231005_03:57:35 230928_10:57:08 - 231002_12:37:20
Extended 230927_11:29:56 230927_11:29:56

2022
Configuration New antenna file Track range to update
Very Extended 221215_03:55:34 221212_04:25:07 - 221214_04:08:35
Extended 221101_08:10:28 221022_02:37:33 - 221030_04:00:18
Compact 221018_02:19:46_fix7 221018_02:19:46 - 221019_04:26:35
Compact 221012_02:29:32 221003_04:33:40 - 221009_04:26:03
Subcompact 220905_07:00:25 220904_07:00:08
Compact 220720_04:32:50_fix52 220720_04:32:50
Extended 220606_14:51:34 200603_03:32:21 - 220606_05:01:55
- 220514_03:53:59 220513_08:57:15
Extended 220322_04:49:55 220321_01:32:37 - 220303_08:59:35 (ant 2)
Extended 220306_07:27:10 220303_08:59:35
- 220227_08:06:54 220227_08:06:54 - 220228_07:30:20 (ant 8 only)

2021
Configuration New antenna file Track range to update
- 211015_03:40:54 211014_04:27:26
Subcompact 210828_04:30:08 210826_09:29:38 - 210827_03:37:22
Compact 210818_03:54:15 210813_02:59:04 - 210817_03:11:52
Compact 210707_02:56:57 210701_06:14:43 - 210706_08:51:44
Compact 210331_02:18:00 210319_05:02:07 - 210324_08:02:30
210325_03:20:56 - 210329_01:58:36*
Compact 210306_02:43:28 210211_11:01:42 - 210305_13:28:45*
Compact 210223_05:07:46 210211_11:01:42
210213_03:06:12 - 210222_01:31:28
Compact 210210_11:05:29 210210_11:05:29
Extended 210116_05:58:31 210114_04:31:11 (ant 7)

2020
Configuration New antenna file Track range to update
Subcompact 200918_02:51:38 200824_03:25:59 - 200914_03:22:21*
Compact 200810_03:27:23 200626_03:40:17 - 200807_04:00:35
Extended 200616_03:44:52 200313_04:29:47 - 200612_07:01:54
Compact 200215_04:28:36 200131_11:06:40 - 200212_03:19:35

2019
Configuration New antenna file Track range that needs updating
Subcompact 191217_02:52:35 191213_03:38:36-191216_04:47:42/
Subcompact 191126_11:01:08 191115_03:17:20-191118_07:30:01/
Extended 191108_06:29:29 191102_04:42:21-191106_17:35:07
Extended 191023_05:25:03 191018_01:52:41-191022_04:58:28/
Subcompact 190911_06:12:11 190908_06:01:14-190909_06:13:05
Extended 1906-07_extended 190629_02:27:57-190710_04:52:47
Very Extended 190612_05:05:29 190531_04:43:31-190610_04:24:53
Very Extended 190530_antennas 190530:05:04:49-190530_11:25:25
Compact 190427_02:38:33 190420_02:43:24-190426_09:04:12
Compact 190410_02:31:12 190405_03:37:20-190409_15:48:57
Compact 190405_03:37:20 190404_05:25:46
Extended 190328_03:41:58 190321_03:16:04-190325_20:00:08
Very Extended 190305_05:30:07 190302_01:58:15-190304_16:55:16

2018
Configuration New antenna file Track range that needs updating
Compact 181108_03:17:08 181101_05:47:23-181107_03:55:19
Compact 181018_03:40:59 181004_02:56:25-181017_09:20:14
Subcompact 180815_03:13:27 180808_05:48:10-180814_14:51:31
Compact 180721_10:05:04 180706_03:54:06-180720_03:24:02
Compact 180610_03:22:22 180525_03:33:00-180605_13:23:17
Extended 180517_05:16:39 180412_10:20:02-180515_04:08:55
Subcompact 180323_09:19:02 180308_11:05:27-180322_09:59:14
Subcompact 180129_03:37:39 180119_03:48:39-180125_03:43:28

2017
Configuration New antenna file Track range that needs updating
Compact 171124_06:29:21 171118_02:56:00-171121_06:37:07
Compact 171111_06:19:29 171012_03:10:38-171108:02:35:44
Very Extended 170925_03:28:46 170919_03:45:57-170923_11:03:17
Compact 170810_05:35:47 170808_03:14:55
Compact 170704_02:11:11 170630_02:32:42 - 170703_10:29:42
Compact 170617_02:38:09 170615_08:09:53 - 170616_03:00:50
Subcompact 170518_12:09:53 170511_05:29:34 - 170517_05:05:14
Compact 170401_07:21:47 170331_04:09:12
Extended 170222_06:05:37 170217_11:28:27 - 170220_05:09:28
Subcompact 170123_05:09:20 170121_04:28:59 - 170122_14:18:47

2016
Configuration New antenna file Track range that needs updating
Compact 161217_09:32:12 161215_02:50:05 - 161216_13:01:35
Extended 161111_03:51:03 161105_05:38:52 - 161110_05:55:35
Extended 161014:02:25:12 160930_04:15:42 - 161013_03:47:59
Subcompact 160909_07:36:24 160907_03:16:18
Subcompact 160819_03:31:24 160812_03:34:52 - 160818_03:46:35
Very Extended 160723_03:12:33 160711_04:25:19 - 160719_18:06:07
Compact 160623_04:16:35 160611_05:06:45 - 160622_04:23:42
Compact 160428_08:44:51 160427_03:41:03
Extended 160402_02:58:29 160330_09:24:52 - 160401_09:37:19
Compact 160327_05:10:03 160325_10:55:28 - 160325_14:57:49
Compact 160211_03:16:35 160112_03:16:48 - 160210_03:29:40

2015
Configuration New antenna file Track range that needs updating
Compact 151224_04:37:19 151212_06:27:58 - 151223_07:05:13
" 151108:04:20:52 151104_03:14:41 - 151107_03:16:58
Subcompact 151021_02:46:50 151017_01:19:15 - 151020_06:20:03
Extended 150918_03:25:05 150912_03:41:30 - 150916_05:05:51
Compact 150827_04:06:59 150819_03:37:16 - 150823_05:03:51
" 150819_03:37:16 150812_03:28:13 - 150817_04:56:21
" 150807_06:15:50 150625_06:20:52 - 150806_07:11:41
Subcompact 150606_06:50:15 150605_07:09:09 - 150605_14:10:30
Compact 150530_07:02:12 150529_05:16:43 - 150529_09:35:53
" 150422_05:15:17 150410_04:06:43 - 150421_17:48:02
Extended 150404_03:12:17 150402_11:20:30 - 150403_08:30:25
" 150306_04:50:05 150225_03:21:49 - 150302_17:32:24
" 150203_03:40:05 150130_03:42:21 - 150202_13:45:43
Very Extended 150113_03:26:19 141218_03:15:38 - 150112_03:09:00

2014
Configuration New antenna file Track range that needs updating
Subcompact 141119_16:46:01 141118_02:15:14 - 141119_07:02:47
Compact 141001_06:03:07 140926_03:03:39 - 140929_08:56:23
Compact-north 140925_04:43:47 140912_03:43:31 - 140924_02:38:56
Extended 140829_04:14:04 140823_02:53:25 - 140828_10:27:11
Very Extended 140820_03:15:20 140811_03:13:00 - 140819_10:17:00
Subcompact 140723_03:25:40 140722_03:35:57 - 140722_03:35:57
Compact 140627_04:31:05 140606_07:26:32 - 140626_08:08:14
" 140516_03:53:10 140514_03:57:00 - 140515_04:05:29
Compact-north 140430_04:00:05 140419_04:58:39 - 140429_03:48:37
Extended 140408_02:56:19 140404_09:09:27 - 140406_04:22:19
Subcompact no corrections needed no corrections needed
Compact no corrections needed no corrections needed

2013
Configuration New antenna file Track range that needs updating
Extended 131119_03:20:13 131105_04:29:05 - 131118_13:32:02
" See Operations Log #27220 130915_08:08:27 - 130917_08:18:32
Subcompact See Operations Log #27220 130912_04:22:12 - 130914_03:08:29
" 130830_02:42:25 130822_03:41:28 - 130828_10:04:12
Compact no corrections needed no corrections needed
Extended 130607_04:09:07 130524_03:24:11 - 130606_06:16:01
Subcompact 130509_02:37:08 130426_02:37:09 - 130508_10:45:41
Compact 130209_01:44:55 130208_04:07:00 only
Very Extended 130201_01:49:25 130124_18:38:40 - 130128_04:49:35
Extended 121222_04:58:49 121221_03:14:19 only

2012
Configuration New antenna file Track range that needs updating
Compact 121031_02:24:42 121025_05:18:58 - 121030_16:20:35
Very Extended 121022_08:04:40 121013_03:47:42 - 121022_03:31:01
" 120928_06:40:32 120922_03:12:07 - 120927_03:42:36
Extended 120905_04:09:56 120830_02:46:20 - 120904_16:51:24
" 120829_05:33:51 120819_07:12:44 - 120828_08:48:24
Subcompact 120716_03:08:39 120713_03:19:29 - 120715_13:21:15
" 120713_03:19:29 120712_04:31:39 only
Compact 120609_02:42:20 120427_02:55:17 - 120608_06:20:05
Very Extended A=2,3 Compact, others Very Extended 120426_08:02:02 only
" 120419_03:50:13 120330_04:14:07 - 120418_15:14:14
Extended 120308_16:15:45 120301_03:33:24 - 120306_11:09:20
" 120210_03:13:45 120204_04:30:07 - 120209_03:27:03
" 120128_03:09:17 120120_03:10:34 - 120126_04:00:38
Subcompact 120111_08:48:11 120106_04:27:24 - 120110_03:20:26

2011
Configuration New antenna file Track range that needs updating
Compact 111126_04:01:57 111117_06:13:46 - 111125_05:14:26
" 111108_02:23:28 111105_04:41:31 - 111107_03:21:52
" 111025_02:32:32 110923_03:14:24 - 111024_04:04:05
Very Extended 110907_02:45:07 110827_04:14:41 - 110906_09:40:50
Extended 110723_03:02:59 110715_02:58:09 - 110722_09:58:45
Subcompact 110628_05:57:08 110624_04:47:44 - 110627_06:37:44
Compact 110603_04:22:01 110528_04:36:00 - 110601_02:51:22
Subcompact 110301_02:48:04 110228_08:39:10 only
Extended 110211_06:00:00 110204_03:36:22 - 110209_03:02:05
Very Extended 110126_18:56:29 110124_03:29:41 - 110126_03:37:09
" 110105_15:02:41 101231_04:46:13 - 110105_02:53:56

2010
Configuration New antenna file Track range that needs updating
Compact 101024_05:01:53 101021_04:18:52 - 101023_03:57:19
Extended 100831_02:37:52 100827_03:18:05 - 100830_03:39:21
Subcompact 100813_03:22:18 100812_03:13:00 only
Compact-north 100731_03:09:42 100730_02:54:26 only
* Highly recommended but not required. These are fine tuning corrections to the baseline soltuions.