Goldstone/Green Bank Telescope Bistatic Radar Images of Near-Earth Asteroid 2017 VR12
Goldstone Radar Observations Planning: Asteroid 2017 VR12
Delay-Doppler images of 2017 VR12 obtained on March 6, 2018 using transmissions at the 34 m DSS-13 antenna at the Goldstone Deep Space Communications Complex and reception at the Green Bank Telescope. The resolution is 3.75 m x 0.5 Hz. Range increases down and Doppler frequency increases to the right, so rotation appears counterclockwise. Time increases from left to right and top to bottom. The asteroid is somewhat elongated and angular and completes about 2/3 of one rotation during the sequence shown. The images were obtained at C-band (7190 MHz, 4.2 cm) using the 80 kW transmitter on DSS-13.
Bistatic DSS-14/DSS-13 Delay-Doppler images of 2017 VR12 obtained on March 7, 2018. Resolution is 3.75 m x 0.5 Hz. These are X-band (8560 MHz, 3.5 cm) images.
Bistatic DSS-13/Green Bank Telescope Delay-Doppler images of 2017 VR12 obtained on March 7, 2018. resolution is 3.75 m x 0.5 Hz. The sequence spans 1.8 hours or about 1.3 rotations by the asteroid.
2017 VR12 was discovered on November 10, 2017 by Pan-STARRS 1. This asteroid will approach Earth within 3.8 lunar distances (0.0097 au) on March 7, 2018 and it should be a very strong radar target. Nothing is known about its physical properties except its absolute magnitude of 20.5, which suggests a diameter of about 250 meters. Update on Feb. 26: T. Lister and J. Chatelain (pers. comm.) and Y. Krugly (pers. comm.) report a preliminary rotation period of 1.4 hours with an amplitude of 0.2 magnitudes. P. Pravec has obtained the same rotation period. M. Devogele reports that spectroscopy obtained at Lowell Observatory indicates that 2017 VR12 is a V-class object. Consequently, we expect a high optical albedo and a high radar circular polarization ratio. Due to its close approach and our rough guess for the diameter, we expect that the SNRs at Goldstone will be strong enough for imaging at 3.75 m/pixel resolution using transmissions from DSS-14 and at 1.875 m/pixel using transmissions from DSS-13. Time is scheduled at both facilities during March 5-7. 2017 VR12 will be brighter than 16th magnitude for about four weeks during February and March of 2018. The asteroid is predicted to reach 12th magnitude for three days in early March when it will be visible in small telescopes for experienced observers at sites with dark skies. Due to its rapid motion in declination, 2017 VR12 is visible at Arecibo on only two days during March 6 and 7. We may also request time at Green Bank to receive Goldstone transmissions and time might be scheduled to observe this object with radar in Australia. The 2018 encounter is the closest by this asteroid currently known. This object is on the NHATS list of potential spacecraft mission targets, although no mission is actually planned for this object. 2017 VR12 is classified as a "Potentially Hazardous Asteroid" by the Minor Planet Center.
Orbital and Physical Characteristics
Name 2017 VR12
Number not numbered
Discoverer Pan-STARRS 1
Discovery date 2017 Nov 10
orbit type Amor
Close approach date 2017 Mar 07
Close approach dist. 0.0097 au
Close approach dist. 3.76 lunar distances
semimajor axis 1.375 au
eccentricity 0.272
inclination 9.2 deg
orbital period 1.613 y
perihelion distance 1.001 au
aphelion distance 2.402 au
MOID 0.0090 au
Tisserand parameter 4.760 (asteroidal)
absolute magnitude (H) 20.5
diameter 0.25 km +- a factor of two
optical albedo bright
spectral class V M. Devogele et al., pers. comm.
rotation period 1.4 h T. Lister and J. Chatelain pers. comm.; Y. Krugly pers. comm., P. Pravec pers. comm.
lightcurve amplitude 0.2 mag
pole direction unknown
PHA
Close-approach results:
JPL/Horizons solution 36, 2018 Feb. 26
Date (TDB) Body CA Dist MinDist MaxDist Vrel TCA3Sg Nsigs P_i/p
A.D. 1865 Mar 16.03356 Earth .041983 .001390 .319498 6.413 1.02E5 5904.4 .000000
A.D. 1915 Mar 04.04539 Earth .023798 .005472 .048357 6.363 7498.7 74342. .000000
A.D. 1968 Mar 12.30598 Earth .021574 .020190 .022963 6.273 454.23 34332. .000000
A.D. 2018 Mar 07.32830 Earth .009662 .009661 .009663 6.300 0.71 41090. .000000
A.D. 2026 Mar 19.72812 Earth .053489 .052726 .054250 6.444 221.46 10266. .000000
A.D. 2079 Mar 10.51050 Earth .011760 .010887 .012688 6.249 375.51 59412. .000000
A.D. 2100 Mar 01.53027 Earth .038377 .035829 .040910 6.574 678.01 33631. .000000
A.D. 2166 Mar 18.73461 Earth .043314 .028851 .057466 6.313 4481.0 10236. .000000
A.D. 2187 Feb 24.94305 Earth .070751 .014531 .119450 7.122 10649. 35880. .000000
A.D. 2216 Mar 06.98758 Earth .017161 .007713 .077464 6.369 19030. 64675. .000000
Last update: 2018 March 9
Selected media stories about 2017 VR12:
http://earthsky.org/space/asteroid-2017-vr12-closest-march-6-7-2018
https://www.space.com/39911-stadium-size-asteroid-2017-vr12-earth-flyby.html
https://www.usatoday.com/story/news/2018/03/06/asteroid-could-big-empire-state-building-fly-past-earth-tonight-heres-how-see/401559002/
http://www.newsweek.com/2017-vr12-asteroids-earth-moon-827653
https://astronomynow.com/2018/03/04/see-bright-near-earth-asteroid-2017-vr12-pass-close-to-star-spica-7-8-march/
https://minorplanetcenter.net/mpec/K17/K17V75.html
Goldstone SNRs
2017 VR12: D = 0.25 km, P = 2.2 h, OC albedo = 0.1
Ptx = 100 kW Ptx=180 kW Ptx=180 kW
<---DSS-14---> DSS14/GBT DSS14/DSS13 DSS13/GBT DSS13/AO DSS13/ATCA
DOY start date window RA dec dist runs SNR/day SNR/run SNR/RTT SNR/RTT SNR/RTT SNR/RTT SNR/RTT
53-54 2018 Feb 22-23 21:53-19:36 164 +78 0.044 978 29 1
54-55 2018 Feb 23-24 21:42-19:51 167 +77 0.041 1062 41 1
55-56 2018 Feb 24-25 21:45-19:49 170 +76 0.037 1162 58 2
56-57 2018 Feb 25-26 22:05-19:35 173 +74 0.034 1220 84 3
57-58 2018 Feb 26-27 22:37-18:49 177 +73 0.030 1196 120 4
58-59 2018 Feb 27-28 23:42-18:15 180 +70 0.027 1239 190 6 25
60 2018 Mar 01 00:34-17:46 183 +68 0.024 1312 320 10 41 5 4
61 2018 Mar 02 01:22-17:19 186 +64 0.020 1413 570 17 70 9 7
62 2018 Mar 03 02:08-16:52 189 +58 0.017 1544 1100 30 120 16 12
63 2018 Mar 04 02:53-16:24 192 +50 0.014 1702 2100 56 230 30 22 Goldstone Transmitters
64 2018 Mar 05 03:40-15:53 195 +38 0.012 1854 4300 110 * 450 59 * 43 north north DSS-14 and DSS-13
65 2018 Mar 06 04:32-15:14 198 +21 0.010 1893 7500 180 740 97 74 * 180 * 24 DSS-13
66 2018 Mar 07 05:36-14:22 201 +1 0.010 1638 8300 220 * 900 120 * 88 * 220 * 29 DSS-14 and DSS-13
67 2018 Mar 08 07:03-13:07 203 -20 0.010 1050 4500 150 610 81 57 south 19
Horizons were set at up to 26 deg on some dates prior to Feb. 27 when the asteroid is circumpolar.
The Goldstone DSS-14 monostatic SNRs assume that Ptx = 100 kW. DSS-13 bistatic SNRs assume Ptx = 80 kW.
For DSS-14 bistatic SNRs, assume Ptx = 180 kW.
Yuri Bondarenko et al. also received echoes from DSS-14 transmissions at the 34 m Quasar VLBI
stations at Badary and Zelenchukskaya in Russia on March 5.
Spectroscopy reported by Devogele (pers. comm.) indicates a V-class (i.e., probably basaltic) composition.
V-class NEAs have high optical albedos of ~0.3 - 0.4, so the diameter could be close to 170 meters.
V-class NEAs also tend to have radar albedos > 0.2, so the SNRs above don't change significantly.
SNRs recomputed using D = 0.16 km, P = 1.4 h, and OCalbedo = 0.2 give numbers only about 18% smaller
than those above.
Arecibo SNRs
DOY start date window RA, dec dist runs SNR/day SNR/run
65 2018 Mar 06 05:23-08:05 198, +24 0.010 486 170000 8200 Scheduled Radar speckle at the VLBA: 07:45-08:05 UT
66 2018 Mar 07 05:53-07:39 200, +4 0.010 355 170000 10000 Scheduled Radar speckle at the VLBA: 07:20-07:40 UT
Arecibo SNRs assume Ptx = 400 kW and Tsys = 25 K
We need to remember to provide Arecibo with Goldstone astrometry before their first
track to save them time for imaging. We can do this on both March 5 and 6.
Perhaps use some of the Arecibo time for monostatic imaging and the rest for bistatic
DSS-13/Arecibo 1.9 m imaging.
Track Assignments
Week 10 Tracking for AST 2017 VR12 (DSS-14):
064 0215 0345 0530 0600 DSS-14 GSSR AST 2017 VR12
064 0345 0530 DSS-13 GSSR AST 2017 VR12
065 0355 0525 1000 1030 DSS-13 GSSR AST 2017 VR12
066 0415 0545 0725 0755 DSS-14 GSSR AST 2017 VR12
066 0430 0600 1030 1100 DSS-13 GSSR AST 2017 VR12
068 1110 1305 DSS-35 AST 2017 VR12 DSS-35/ATCA CANCELLED
Goldstone Schedule in more detail:
Ptx=100 kW
UT UT PST Round-trip Duration Monostatic
DOY Date Antenna TX Window TX Window time (sec) hours SNR/RTT
64 Mar 5 DSS-14 0340 0530 1940-2130 Mar 4 12 1.83 110
64 DSS-13 0340 0530 DSS-13 receive only
65 Mar 6 DSS-13 0525 1000 2030-0200 Mar 5 10 5.50 DSS-13 transmit
65 0525-0740? Transmit 80 MHz to Arecibo (stop before VLBA starts at 0745)
65 0800-1000 Transmit to Green Bank
On March 6, monostatic observations at Arecibo will happen before we start to transmit
from DSS-13 to Arecibo. Thus, we will use only part of the Arecibo time for DSS-13/Arecibo 2-meter imaging.
On March 6, we plan to transmit from DSS-13 to Arecibo for only part of the Arecibo track.
66 Mar 7 DSS-14 0535 0725 2135-2325 Mar 6 10 1.83 220 0535-0550 Monostatic or DSS-14/DSS-13
66 DSS-14 0535 0555 Transmit DSS-14 to DSS-13
66 DSS-13 0535 1030 2135-0230 Mar 6 10 4.92
66 DSS-13 0555-0715? Transmit DSS-13 80 MHz to Arecibo (stop before VLBA starts at 0720)
66 DSS-13 0745 1030 Transmit DSS-13 80 MHz to Green Bank
On March 7, monostatic observations at Arecibo will probably happen before we start to transmit
from DSS-13 to Arecibo. We will use only part of the Arecibo time for DSS-13/Arecibo 2-meter imaging.
On March 7 we can also do bistatic DSS-14/DSS-13 at the beginning and during any monostatic
Arecibo imaging (or possibly DSS14/Green Bank 40 MHz imaging).
DSS-14 is scheduled to transmit primarily in case something goes wrong with DSS-13.
67 Mar 8 ...Not scheduled at DSS-14 or DSS-13...
68 Mar 9 DSS-35 1110 1305 0310-0505 Mar 9 DSS-35/ATCA CANCELLED: ATCA NOT AVAILABLE
The DSS-13 times on March 6 and 7 extend beyond when this object is visible at Arecibo. We scheduled
time at Green Bank for observations during those times.
DSS-13 has lower elevation restrictions than DSS-14 if we transmit < 80 kW, so we might be able to transmit
earlier there on March 6 and 7 than is shown above.
Due to the short round-trip times and the 1.4 hour rotation period, the amount of rotation per run will be:
Mar 5 2.5 deg/run --> 15 deg in 6 runs
Mar 6 2.1 deg/run --> 15 deg in 7 runs
Mar 7 1.9 deg/run --> 15 deg in 8 runs (~2.5 minutes)
Rise-Transit-Set times at DSS-36. Horizons = 24.5 degrees
March 6 is the first day that 2017 VR12 is in the beam at DSS-36
JPL/Horizons solution 23
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2018-Mar-06 13:46 r 198.66904 18.55747 0.01002387076313 184.614 68.22 247.95 0.006193
2018-Mar-06 16:35 t 198.84503 16.21650 0.00990766170310 190.965 72.19 262.38 0.005900
2018-Mar-06 19:26 Ns 199.02853 13.76963 0.00982521235519 196.790 77.34 281.08 0.005586
2018-Mar-07 12:27 r 201.24163 -1.29780 0.00966893588004 221.869 90.47 328.81 0.003407
2018-Mar-07 16:38 t 201.50859 -5.00540 0.00971567136039 224.344 89.23 324.29 0.002877
2018-Mar-07 20:54 *s 201.78905 -8.69971 0.00984319336541 224.285 89.49 325.24 0.002356
2018-Mar-08 11:39 r 203.72966 -20.62351 0.01051726164165 214.307 82.00 298.03 0.001107
2018-Mar-08 16:38 t 204.04910 -24.31166 0.01081519044763 208.375 72.93 265.05 0.001193
2018-Mar-08 21:50 *s 204.38826 -27.80294 0.01121931843446 200.335 67.41 244.98 0.001491
2018-Mar-09 11:07 r 206.11899 -35.76141 0.01236344958537 178.809 57.54 209.11 0.002551
2018-Mar-09 16:40 t 206.46985 -38.72758 0.01287874771029 170.137 47.08 171.10 0.002950
2018-Mar-09 22:30 *s 206.84102 -41.40484 0.01350382663411 160.767 41.82 151.99 0.003310
Rise-Transit-Set Times at the ATCA (-47): Horizons = 20 degrees.
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig Goldstone overlap
2018-Mar-06 12:54 r 198.61200 19.24620 0.01006351762612 182.638 67.13 243.99 0.006277 1254-1514
2018-Mar-06 16:32 t 198.83930 16.24448 0.00990659895610 190.932 71.98 261.62 0.005904
2018-Mar-06 20:09 *s 199.07336 13.12799 0.00980821123671 198.204 78.73 286.13 0.005502
2018-Mar-07 11:58 r 201.21071 -0.88620 0.00966701762381 221.478 90.57 329.19 0.003466 1158-1422
2018-Mar-07 16:34 t 201.50246 -4.96643 0.00971256060092 224.380 89.06 323.68 0.002883
2018-Mar-07 21:15 *s 201.80778 -9.01551 0.00985691536665 224.183 89.49 325.25 0.002313
2018-Mar-08 11:20 r 203.71189 -20.39758 0.01050136160974 214.613 82.59 300.16 0.001111 1120-1307
2018-Mar-08 16:35 t 204.04439 -24.29599 0.01081119413007 208.453 72.79 264.55 0.001192
2018-Mar-08 22:02 *s 204.39493 -27.94443 0.01123785319788 199.973 67.16 244.08 0.001506
2018-Mar-09 10:54 r 206.11000 -35.65181 0.01234609935696 179.111 58.01 210.85 0.002537 None
2018-Mar-09 16:37 t 206.46558 -38.71938 0.01287412771871 170.202 46.95 170.65 0.002949
2018-Mar-09 22:37 *s 206.84056 -41.46379 0.01351926667038 160.551 41.66 151.41 0.003317
There's no overlap between DSS-14 or DSS-13 times actually scheduled and view periods at the ATCA.
Elevations at Goldstone:
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta Azi_(a-appr)_Elev
2018-Mar-05 02:10 C 194.54213 42.28866 0.01261822384738 42.0084 7.1435
2018-Mar-05 02:20 N 194.56610 42.20602 0.01260106191021 43.3061 8.4594
2018-Mar-05 02:30 N 194.58971 42.12324 0.01258390740303 44.5753 9.8101
2018-Mar-05 02:40 N 194.61293 42.04030 0.01256676230350 45.8164 11.1941
2018-Mar-05 02:50 A 194.63576 41.95719 0.01254962863368 47.0298 12.6100
2018-Mar-05 03:00 A 194.65821 41.87391 0.01253250845651 48.2158 14.0566
2018-Mar-05 03:10 A 194.68026 41.79045 0.01251540387235 49.3750 15.5325
2018-Mar-05 03:20 194.70191 41.70679 0.01249831701531 50.5078 17.0366
2018-Mar-05 03:30 194.72316 41.62292 0.01248125004960 51.6147 18.5677
2018-Mar-05 03:40 194.74400 41.53885 0.01246420516572 52.6961 20.1246
2018-Mar-05 03:50 194.76444 41.45455 0.01244718457667 53.7526 21.7061
2018-Mar-05 04:00 194.78446 41.37003 0.01243019051404 54.7845 23.3113
2018-Mar-05 04:10 194.80408 41.28527 0.01241322522409 55.7923 24.9390
2018-Mar-05 04:20 194.82330 41.20025 0.01239629096378 56.7764 26.5884
2018-Mar-05 04:30 194.84211 41.11498 0.01237938999672 57.7372 28.2584
2018-Mar-05 04:40 194.86051 41.02944 0.01236252458918 58.6750 29.9481
2018-Mar-05 04:50 194.87852 40.94363 0.01234569700597 59.5900 31.6567
2018-Mar-05 05:00 m 194.89613 40.85753 0.01232890950643 60.4825 33.3832
2018-Mar-05 05:10 m 194.91334 40.77114 0.01231216434030 61.3525 35.1269
2018-Mar-05 05:20 m 194.93017 40.68444 0.01229546374367 62.2001 36.8870
2018-Mar-05 05:30 m 194.94662 40.59744 0.01227880993489 63.0253 38.6627
2018-Mar-05 05:40 m 194.96269 40.51011 0.01226220511057 63.8279 40.4532
2018-Mar-05 05:50 m 194.97840 40.42246 0.01224565144151 64.6074 42.2580
2018-Mar-05 06:00 m 194.99374 40.33447 0.01222915106870 65.3634 44.0762
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta Azi_(a-appr)_Elev
2018-Mar-06 04:00 197.61138 25.96959 0.01053326186770 68.0216 14.2059
2018-Mar-06 04:10 197.63053 25.84815 0.01052189951230 69.3709 16.0294
2018-Mar-06 04:20 197.64927 25.72644 0.01051058707951 70.7106 17.8710
2018-Mar-06 04:30 197.66762 25.60446 0.01049932729499 72.0431 19.7297
2018-Mar-06 04:40 197.68556 25.48219 0.01048812288771 73.3712 21.6042
2018-Mar-06 04:50 197.70311 25.35963 0.01047697658496 74.6978 23.4933
2018-Mar-06 05:00 197.72026 25.23678 0.01046589110737 76.0257 25.3961
2018-Mar-06 05:10 197.73703 25.11362 0.01045486916398 77.3582 27.3113
2018-Mar-06 05:20 197.75341 24.99017 0.01044391344724 78.6989 29.2378
2018-Mar-06 05:30 197.76940 24.86640 0.01043302662803 80.0515 31.1746
2018-Mar-06 05:40 197.78502 24.74231 0.01042221135077 81.4201 33.1205
2018-Mar-06 05:50 197.80028 24.61790 0.01041147022846 82.8094 35.0745
2018-Mar-06 06:00 m 197.81517 24.49317 0.01040080583787 84.2245 37.0352
2018-Mar-06 06:10 m 197.82972 24.36810 0.01039022071469 85.6710 39.0015
2018-Mar-06 06:20 m 197.84391 24.24270 0.01037971734879 87.1555 40.9720
2018-Mar-06 06:30 m 197.85778 24.11696 0.01036929817954 88.6853 42.9453
2018-Mar-06 06:40 m 197.87132 23.99088 0.01035896559122 90.2691 44.9200
2018-Mar-06 06:50 m 197.88455 23.86445 0.01034872190851 91.9167 46.8942
2018-Mar-06 07:00 m 197.89747 23.73767 0.01033856939207 93.6395 48.8660
2018-Mar-06 07:10 m 197.91010 23.61053 0.01032851023427 95.4513 50.8333
2018-Mar-06 07:20 m 197.92246 23.48304 0.01031854655498 97.3680 52.7934
2018-Mar-06 07:30 m 197.93455 23.35520 0.01030868039756 99.4091 54.7434
2018-Mar-06 07:40 m 197.94639 23.22699 0.01029891372491 101.5976 56.6797
2018-Mar-06 07:50 m 197.95799 23.09842 0.01028924841570 103.9615 58.5980
2018-Mar-06 08:00 m 197.96937 22.96949 0.01027968626081 106.5352 60.4929
2018-Mar-06 08:10 m 197.98054 22.84019 0.01027022895983 109.3601 62.3578
2018-Mar-06 08:20 m 197.99151 22.71053 0.01026087811776 112.4875 64.1844
2018-Mar-06 08:30 m 198.00231 22.58050 0.01025163524196 115.9794 65.9622
2018-Mar-06 08:40 m 198.01295 22.45011 0.01024250173922 119.9111 67.6778
2018-Mar-06 08:50 m 198.02344 22.31935 0.01023347891297 124.3717 69.3137
2018-Mar-06 09:00 m 198.03379 22.18823 0.01022456796083 129.4627 70.8477
2018-Mar-06 09:10 m 198.04404 22.05674 0.01021576997222 135.2911 72.2517
2018-Mar-06 09:20 m 198.05419 21.92490 0.01020708592627 141.9541 73.4904
2018-Mar-06 09:30 m 198.06426 21.79269 0.01019851668989 149.5080 74.5226
2018-Mar-06 09:40 m 198.07427 21.66012 0.01019006301612 157.9249 75.3029
2018-Mar-06 09:50 m 198.08423 21.52719 0.01018172554263 167.0463 75.7881
2018-Mar-06 10:00 t 198.09417 21.39391 0.01017350479047 176.5673 75.9462
2018-Mar-06 10:10 m 198.10410 21.26028 0.01016540116312 186.0827 75.7650
2018-Mar-06 10:20 m 198.11403 21.12630 0.01015741494566 195.1883 75.2561
2018-Mar-06 10:30 m 198.12399 20.99197 0.01014954630424 203.5820 74.4507
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta Azi_(a-appr)_Elev
2018-Mar-07 04:00 200.32363 5.96468 0.00968056323625 83.7593 1.5190
2018-Mar-07 04:10 200.34224 5.81740 0.00967762672749 85.3136 3.4520
2018-Mar-07 04:20 200.36045 5.67003 0.00967475495122 86.8663 5.3902
2018-Mar-07 04:30 200.37826 5.52257 0.00967195080011 88.4213 7.3318
2018-Mar-07 04:40 200.39568 5.37503 0.00966921716415 89.9824 9.2753
2018-Mar-07 04:50 200.41271 5.22739 0.00966655692512 91.5535 11.2191
2018-Mar-07 05:00 200.42935 5.07967 0.00966397295101 93.1386 13.1614
2018-Mar-07 05:10 200.44560 4.93187 0.00966146809050 94.7419 15.1006
2018-Mar-07 05:20 200.46146 4.78397 0.00965904516745 96.3678 17.0350
2018-Mar-07 05:30 200.47695 4.63600 0.00965670697537 98.0209 18.9625
2018-Mar-07 05:40 200.49207 4.48795 0.00965445627204 99.7060 20.8813
2018-Mar-07 05:50 200.50682 4.33981 0.00965229577406 101.4281 22.7893
2018-Mar-07 06:00 200.52121 4.19160 0.00965022815160 103.1927 24.6844
2018-Mar-07 06:10 200.53524 4.04331 0.00964825602310 105.0055 26.5640
2018-Mar-07 06:20 200.54893 3.89495 0.00964638195016 106.8726 28.4256
2018-Mar-07 06:30 200.56229 3.74652 0.00964460843245 108.8004 30.2664
2018-Mar-07 06:40 200.57532 3.59802 0.00964293790280 110.7959 32.0833
2018-Mar-07 06:50 200.58804 3.44946 0.00964137272238 112.8664 33.8730
2018-Mar-07 07:00 m 200.60045 3.30083 0.00963991517600 115.0198 35.6317
2018-Mar-07 07:10 m 200.61256 3.15214 0.00963856746753 117.2642 37.3555
2018-Mar-07 07:20 m 200.62440 3.00341 0.00963733171559 119.6082 39.0397
2018-Mar-07 07:30 m 200.63596 2.85461 0.00963620994923 122.0608 40.6795
2018-Mar-07 07:40 m 200.64727 2.70578 0.00963520410389 124.6311 42.2694
2018-Mar-07 07:50 m 200.65833 2.55689 0.00963431601756 127.3281 43.8034
2018-Mar-07 08:00 m 200.66916 2.40797 0.00963354742702 130.1607 45.2749
2018-Mar-07 08:10 m 200.67978 2.25901 0.00963289996436 133.1372 46.6769
2018-Mar-07 08:20 m 200.69020 2.11002 0.00963237515372 136.2648 48.0016
2018-Mar-07 08:30 m 200.70043 1.96100 0.00963197440814 139.5492 49.2407
2018-Mar-07 08:40 m 200.71049 1.81196 0.00963169902675 142.9937 50.3856
2018-Mar-07 08:50 m 200.72040 1.66291 0.00963155019208 146.5988 51.4272
2018-Mar-07 09:00 m 200.73016 1.51384 0.00963152896771 150.3611 52.3563
2018-Mar-07 09:10 m 200.73981 1.36476 0.00963163629602 154.2730 53.1639
2018-Mar-07 09:20 m 200.74935 1.21567 0.00963187299632 158.3216 53.8413
2018-Mar-07 09:30 m 200.75880 1.06659 0.00963223976312 162.4889 54.3806
2018-Mar-07 09:40 m 200.76817 0.91752 0.00963273716473 166.7516 54.7749
2018-Mar-07 09:50 m 200.77749 0.76846 0.00963336564204 171.0820 55.0190
2018-Mar-07 10:00 m 200.78677 0.61941 0.00963412550761 175.4487 55.1093
2018-Mar-07 10:10 t 200.79603 0.47038 0.00963501694499 179.8182 55.0443
2018-Mar-07 10:20 m 200.80529 0.32138 0.00963604000832 184.1571 54.8247
2018-Mar-07 10:30 m 200.81456 0.17242 0.00963719462217 188.4331 54.4530
2018-Mar-07 10:40 m 200.82386 0.02349 0.00963848058164 192.6172 53.9338
2018-Mar-07 10:50 m 200.83320 -0.12540 0.00963989755275 196.6847 53.2731
2018-Mar-07 11:00 m 200.84261 -0.27424 0.00964144507305 200.6159 52.4784
Rise/Set times at Green Bank
Horizons = 20 degrees
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta
2018-Mar-05 00:54 r 194.41324 42.96157 0.01272862968838
2018-Mar-05 07:28 t 194.99822 39.54717 0.01207693488804
2018-Mar-05 13:37 *s 195.52645 35.80037 0.01156755516941
2018-Mar-06 01:52 r 197.36877 27.53433 0.01065854426845 DSS-13: 0430-1000
2018-Mar-06 07:31 t 197.82246 23.33150 0.01029798818613
2018-Mar-06 12:52 *s 198.23342 18.98726 0.01006491953193
2018-Mar-07 03:02 r 200.21011 6.80085 0.00967452695456 DSS-13: 0535-1030
2018-Mar-07 07:32 t 200.52866 2.79411 0.00962709547844
2018-Mar-07 11:55 *s 200.82378 -1.12334 0.00966643782027
2018-Mar-08 04:37 r 202.93819 -15.43060 0.01014321437758
2018-Mar-08 07:35 t 203.11712 -17.80837 0.01028140528093
2018-Mar-08 10:33 As 203.28844 -20.08258 0.01045486429310
Uncertainties
JPL/Horizons solution 37, # obs: 220 (2017-2018)
2018 Feb 27
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2018-Mar-01 00:00 * 181.96768 68.67703 0.02486493691645 2.141 1.80 6.54 0.001944
2018-Mar-02 00:00 * 185.12493 65.14810 0.02158303697732 3.244 1.97 7.15 0.001883
2018-Mar-03 00:00 * 188.23205 60.28601 0.01842161779174 5.120 2.37 8.61 0.001810
2018-Mar-04 00:00 * 191.26733 53.38536 0.01545883832721 8.370 3.34 12.15 0.001712
2018-Mar-05 00:00 * 194.21269 43.34683 0.01283698459770 13.933 5.56 20.22 0.001556 *
2018-Mar-06 00:00 * 197.05430 28.80804 0.01081067735788 22.452 9.81 35.64 0.001284 *
2018-Mar-07 00:00 * 199.78301 9.45469 0.00976075509123 31.320 14.68 53.35 0.000843 *
2018-Mar-08 00:00 * 202.39414 -11.55697 0.01000014201372 33.766 15.10 54.87 0.000330
2018-Mar-09 00:00 * 204.88576 -29.33006 0.01144649019643 29.030 10.89 39.57 0.000280
2018-Mar-10 00:00 * 207.25685 -42.13444 0.01372022247913 22.661 6.58 23.91 0.000541
JPL/Horizons solution 24, # obs: 129 (2017-2018)
2018 Feb 01
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2018-Mar-01 00:00 * 181.96745 68.67687 0.02486518208140 10.787 2.70 9.81 0.004989
2018-Mar-02 00:00 * 185.12463 65.14796 0.02158328255536 14.227 3.38 12.29 0.004895
2018-Mar-03 00:00 * 188.23170 60.28590 0.01842186392090 19.828 4.89 17.76 0.004761
2018-Mar-04 00:00 * 191.26693 53.38533 0.01545908399500 29.316 8.19 29.76 0.004543
2018-Mar-05 00:00 * 194.21223 43.34697 0.01283722543040 45.390 15.21 55.29 0.004146
2018-Mar-06 00:00 * 197.05378 28.80850 0.01081090082333 69.816 28.18 102.41 0.003397
2018-Mar-07 00:00 * 199.78246 9.45558 0.00976093650682 94.912 42.97 156.17 0.002132
2018-Mar-08 00:00 * 202.39354 -11.55580 0.01000025771886 101.204 44.73 162.56 0.000654
2018-Mar-09 00:00 * 204.88511 -29.32893 0.01144654051657 86.877 32.94 119.71 0.001005
2018-Mar-10 00:00 * 207.25617 -42.13349 0.01372022457775 68.092 20.69 75.20 0.001867
JPL/Horizons solution 23, # obs: 122 (2017-2018):
2018 Jan 25
2018-Mar-01 00:00 * 181.97191 68.67678 0.02486485573535 32.985 3.33 12.10 0.010023
2018-Mar-02 00:00 * 185.12920 65.14770 0.02158295169018 40.375 4.50 16.37 0.009926
2018-Mar-03 00:00 * 188.23634 60.28539 0.01842153851103 51.709 7.31 26.56 0.009761
2018-Mar-04 00:00 * 191.27162 53.38444 0.01545878151697 70.371 13.67 49.68 0.009442
2018-Mar-05 00:00 * 194.21694 43.34550 0.01283697721340 102.133 27.59 100.26 0.008782
2018-Mar-06 00:00 * 197.05850 28.80630 0.01081075954731 151.791 54.21 197.01 0.007417
2018-Mar-07 00:00 * 199.78716 9.45285 0.00976096713254 205.469 86.36 313.86 0.004972
2018-Mar-08 00:00 * 202.39821 -11.55832 0.01000048659571 222.581 93.18 338.65 0.001941
2018-Mar-09 00:00 * 204.88974 -29.33069 0.01144692827202 195.891 70.95 257.87 0.001688
2018-Mar-10 00:00 * 207.26075 -42.13455 0.01372071617170 157.667 46.17 167.81 0.003433
JPL/Horizons solution 12, # obs: 81 (34 days)
2017 Dec 20
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2018-Mar-01 00:00 * 182.06991 68.68842 0.02483599093757 679.916 13.49 49.03 0.123477
2018-Mar-02 00:00 * 185.23404 65.15538 0.02155408510330 812.477 32.41 117.80 0.123366
2018-Mar-03 00:00 * 188.34751 60.28552 0.01839283879152 1000.146 72.16 262.27 0.122375
2018-Mar-04 00:00 * 191.38853 53.37038 0.01543065725032 1282.413 157.80 573.50 0.119392
2018-Mar-05 00:00 * 194.33898 43.30543 0.01281039113557 1726.065 343.07 1246.89 0.111932
2018-Mar-06 00:00 * 197.18504 28.72366 0.01078779405826 2385.816 698.57 2538.94 0.095137
2018-Mar-07 00:00 * 199.91758 9.32160 0.00974500529328 3080.351 1133.38 4119.24 0.063808
2018-Mar-08 00:00 * 202.53197 -11.70962 0.00999407971280 3283.583 1239.01 4503.13 0.023684
2018-Mar-09 00:00 * 205.02633 -29.46461 0.01144925882712 2905.396 959.29 3486.49 0.021332
2018-Mar-10 00:00 * 207.39970 -42.23955 0.01372919352095 2373.205 639.83 2325.43 0.045680
JPL/Horizons solution 1, # obs: 28 (4 days)
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2018-Mar-01 00:00 * 193.88426 69.27857 0.02284591230523 104528.674 6695.40 24334.11 11.134462
2018-Mar-02 00:00 * 197.53741 65.27860 0.01957716478192 127359.063 11296.88 41057.97 10.935696
2018-Mar-03 00:00 * 201.05950 59.60273 0.01645282652780 159904.476 19835.59 72091.55 10.535038
2018-Mar-04 00:00 * 204.42883 51.27921 0.01357732530539 207847.365 36528.84 132762.39 9.733722
2018-Mar-05 00:00 * 207.63113 38.81787 0.01114918917528 277068.551 68434.74 248722.89 8.135051
2018-Mar-06 00:00 * 210.65943 20.78759 0.00952084124750 357413.949 115081.53 418258.49 5.195089
2018-Mar-07 00:00 * 213.51352 -1.46942 0.00913263695061 394253.088 138435.37 503136.94 1.693952
2018-Mar-08 00:00 * 216.19809 -22.31960 0.01012749509342 352082.441 109443.85 397768.62 4.071258
2018-Mar-09 00:00 * 218.71935 -37.77050 0.01216804615316 281796.911 69027.95 250878.91 6.825196
2018-Mar-10 00:00 * 221.08326 -48.20717 0.01482506601625 223580.901 42260.83 153595.04 8.499959
Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination:
(JPL/Horizons solution 18, 2018 January 4)
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-O-T /r T-O-M/Illu%
2018-Feb-15 00:00 144.88026 80.29814 0.07330188233321 17.10 112.4494 /T 115.7/ 0.7
2018-Feb-16 00:00 146.65050 80.20528 0.06984703407949 17.01 112.2058 /T 112.9/ 0.0
2018-Feb-17 00:00 148.56750 80.07130 0.06638463753738 16.90 111.9990 /T 109.2/ 1.3
2018-Feb-18 00:00 150.63573 79.88917 0.06291538506960 16.80 111.8349 /T 104.7/ 4.5
2018-Feb-19 00:00 152.85766 79.65009 0.05944014912074 16.68 111.7206 /L 99.7/ 9.8
2018-Feb-20 00:00 155.23325 79.34303 0.05596002816914 16.55 111.6649 /L 94.4/ 16.8
2018-Feb-21 00:00 157.75944 78.95401 0.05247641114435 16.41 111.6791 /L 88.9/ 25.5
2018-Feb-22 00:00 160.42967 78.46508 0.04899106864637 16.27 111.7771 /L 83.4/ 35.5
2018-Feb-23 00:00 163.23353 77.85295 0.04550628443685 16.10 111.9773 /L 78.2/ 46.3
2018-Feb-24 00:00 166.15666 77.08689 0.04202504951755 15.92 112.3037 /L 73.2/ 57.6
2018-Feb-25 00:00 169.18081 76.12553 0.03855135665201 15.72 112.7887 /L 68.9/ 68.6
2018-Feb-26 00:00 172.28426 74.91204 0.03509066146836 15.50 113.4766 /L 65.2/ 78.9
2018-Feb-27 00:00 175.44252 73.36622 0.03165062998323 15.25 114.4296 /L 62.4/ 87.7
2018-Feb-28 00:00 178.62927 71.37159 0.02824239883666 14.97 115.7372 /L 60.3/ 94.3
2018-Mar-01 00:00 181.81749 68.75346 0.02488279406734 14.65 117.5312 /L 58.9/ 98.5
2018-Mar-02 00:00 184.98075 65.24088 0.02159842189140 14.27 120.0096 /L 57.6/100.0
2018-Mar-03 00:00 188.09436 60.40042 0.01843355380071 13.83 123.4697 /L 56.0/ 98.7
2018-Mar-04 00:00 191.13640 53.52811 0.01546579679049 13.32 128.3331 /L 53.2/ 95.0
2018-Mar-05 00:00 194.08861 43.52345 0.01283660911800 12.73 135.0247 /L 48.5/ 89.2
2018-Mar-06 00:00 196.93700 29.01198 0.01079983202525 12.13 143.0422 /L 41.5/ 81.8
2018-Mar-07 00:00 199.67229 9.64704 0.00973722911578 11.78 147.7813 /L 35.4/ 73.3
2018-Mar-08 00:00 202.28966 -11.43101 0.00996597083364 11.97 142.4693 /L 36.8/ 64.2
2018-Mar-09 00:00 204.78716 -29.27900 0.01140689969729 12.56 131.9618 /L 44.8/ 54.6
2018-Mar-10 00:00 207.16375 -42.13093 0.01367911939949 13.21 122.8078 /L 53.4/ 45.1
2018-Mar-11 00:00 209.41881 -50.95792 0.01643793467722 13.80 116.2069 /L 60.8/ 35.9
2018-Mar-12 00:00 211.55240 -57.09858 0.01947403205499 14.30 111.6071 /L 67.2/ 27.1
2018-Mar-13 00:00 213.56547 -61.50578 0.02267270537123 14.73 108.3773 /L 73.1/ 19.1
2018-Mar-14 00:00 215.45990 -64.77419 0.02597039738235 15.09 106.0740 /L 78.8/ 12.2
2018-Mar-15 00:00 217.23835 -67.27019 0.02933020940588 15.40 104.4103 /L 84.5/ 6.6
2018-Mar-16 00:00 218.90415 -69.22453 0.03272953875491 15.68 103.2003 /L 90.2/ 2.5
2018-Mar-17 00:00 220.46113 -70.78717 0.03615380845496 15.92 102.3215 /L 96.0/ 0.4
2018-Mar-18 00:00 221.91353 -72.05876 0.03959316527651 16.13 101.6907 /L 101.7/ 0.3
2018-Mar-19 00:00 223.26584 -73.10885 0.04304065981119 16.32 101.2500 /L 107.1/ 2.5
2018-Mar-20 00:00 224.52270 -73.98685 0.04649119662555 16.50 100.9577 /L 112.0/ 6.9
2018-Mar-21 00:00 225.68882 -74.72870 0.04994090213921 16.65 100.7837 /L 116.1/ 13.5
2018-Mar-22 00:00 226.76881 -75.36111 0.05338672900145 16.80 100.7050 /L 119.0/ 21.9
2018-Mar-23 00:00 227.76712 -75.90432 0.05682620012376 16.93 100.7046 /L 120.5/ 31.8
2018-Mar-24 00:00 228.68793 -76.37392 0.06025723866555 17.05 100.7689 /L 120.3/ 42.7
2018-Mar-25 00:00 229.53505 -76.78210 0.06367805311304 17.16 100.8874 /L 118.3/ 54.1
Setups
Due to the 1.4 h rotation period and our guess of 250 m for the diameter,
the bandwidth could be about 18 Hz at DSS-14.
CW setup:
---------------------------------------------------------------------------
TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: no hopping
Bandwidth: 5000 Hz
TXoffset +500 Hz
FFT for PFS files: 500 for 10.0 Hz resolution
Ranging setups:
---------------------------------------------------------------------------
10-usec
baud 10 usec
code 127
PRP 1270 usec
FFT 64
ncoh 1
bandwidth 787 Hz
resolution 12.3 Hz
TXOFF +100 Hz (echo in column 32 + 8 = 40)
---------------------------------------------------------------------------
11-usec
baud 11 usec
code 127
PRP 1397 usec
FFT 64
ncoh 1
bandwidth 716 Hz
resolution 11.2 Hz
TXOFF +100 Hz (echo in column 32 + 9 = 41)
-------------------------------------------------------------------------
1-usec
baud 1 usec
code 255
ncoh 2
bandwidth 1960.8 Hz
FFT 512
resolution 3.8 Hz
TXOFF +200 Hz
The 1 usec setup provides sufficient resolution to spatially resolve the asteroid
into about 17 rows.
---------------------------------------------------------------------
Instructions
NOTE: Data should be moved to the appropriate subdirectories in
aardvark:/export/data0/2017vr12/raw/
POINTING:
OSOD and predicts will be on aardvark:
...not available yet...
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
... not available yet...
Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.??
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
GOLDSTONE MASTERLOG
==============================================================================
Receive TX
Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes
------------------------------------------------------------------------------
Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 183-601 | FAX: (818) 393-4445
Jet Propulsion Laboratory | email: lance.benner@jpl.nasa.gov
California Institute of Technology | Plan: To live long and prosper
Pasadena, CA 91109-8099
https://echo.jpl.nasa.gov/asteroids/2017VR12/2017VR12_planning.2017.html
Asteroid Radar Astronomy