Goldstone Radar Observations Planning: (271480) 2004 FX31 and 2021 EB1


Background


2004 FX31    
(271480) 2004 FX31 was discovered on March 31, 2004 by Lowell Observatory-LONEOS.
This object makes a relatively distant approach within 0.093 au (~36 lunar distances) on March 11, 2021.
The NEOWISE team (Mainzer et al., AJ 2016) reported a diameter of ~700 m and a high optical albedo of ~0.35.
No other physical properties are known. 2004 FX31 will be a weak radar target at Goldstone and may difficult 
to detect unless its rotation period is slow.

2004 FX31's orbit has a high eccentricity (e = 0.44) and inclination (i = 24.8 deg) and 2021 is the closest flyby
until its approach within 0.077 au in 2079. 2004 FX31 is a daytime object until early March, so it is unlikely 
that lightcurves and a rotation period will be available before the radar observations on March 11. 


2021 EB1




Orbital and Physical Characteristics  
Name                     2004 FX31                       2021 EB1
Asteroid number          271480                          not numbered
Discoverer               LONEOS                          Catalina Sky Survey
Discovery date           2004 Mar 31                     2021 Mar  6
orbit type               Apollo                          Apollo
Close approach distance  0.093 au                        0.0219 au (8.5 lunar distances)
Close approach date      2021 Mar 11                     2021 Mar 11

semimajor axis           1.261 au                        2.615 au
eccentricity             0.44                            0.655
inclination              24.8 deg                        13.1 deg
Orbital period           1.42 years                      4.22 y
perihelion distance      0.703 au                        0.903 au
aphelion distance        1.818 au                        4.328 au
MOID                     0.066 au                        0.0201 au

absolute magnitude (H)   17.6                            23.5
diameter                 0.709+/-0.223 km (NEOWISE)      60 m +- a factor of two
optical albedo           0.352+/-0.222    (NEOWISE)      unknown
rotation period          unknown                         unknown
lightcurve amplitude     unknown                         unknown
pole direction           unknown                         unknown
spectral class           unknown                         unknown
PHA?                     No                              No

Last update: 2021 March 10 


Discovery M.P.E.C.


2004 FX31
https://minorplanetcenter.net//mpec/K04/K04F97.html

2021 EB1
https://www.minorplanetcenter.net/mpec/K21/K21E42.html


SNR Calculations

Goldstone SNRs

2004 FX31:  D = 0.71 km,  P = 2.2 h,  OC albedo = 0.1
DOY  start date    window        RA, dec   dist  runs   SNR/day SNR/run
67  2021 Mar 08  13:17-21:08    307,  -7  0.096   149      17      2
68  2021 Mar 09  12:44-21:05    304,  -2  0.094   162      19      2
69  2021 Mar 10  12:11-21:02    300,  +3  0.093   174      21      2
70  2021 Mar 11  11:39-20:57    296,  +7  0.093   183      22      2  Scheduled 1215-1415 
71  2021 Mar 12  11:07-20:51    293, +12  0.094   189      22      2
72  2021 Mar 13  10:37-20:44    289, +16  0.096   193      20      2  
73  2021 Mar 14  10:08-20:36    285, +21  0.098   194      18      1
74  2021 Mar 15  09:39-20:28    282, +25  0.102   193      16      1
SNRs assume Tsys = 17 K.


2021 EB1: D = 0.06 km, P = 0.5 h, OC albedo = 0.1 start date window RA, dec dist runs SNR/day SNR/run 2021 Mar 8 03:14-21:58 242, +69 0.031 1004 22 1 2021 Mar 9 06:04-22:28 272, +61 0.026 1075 48 2 2021 Mar 10 08:58-22:28 292, +45 0.022 1044 76 3 2021 Mar 11 10:57-22:13 304, +25 0.022 891 72 3 * Overlaps 2004 FX31 entirely 2021 Mar 12 12:19-21:50 312, +7 0.025 668 40 2 2021 Mar 13 13:21-21:26 317, -6 0.031 472 17 1

Track Assignments


DOY    BOA   BOT   EOT   EOA
70     1045  1215  1415  1445  GSSR AST 2004 FX31   Overlaps 2021 EB1
72     1110  1240  1410  1440  GSSR AST 2004 FX31   Asteroid track changed to Orbital Debris

Goldstone tracks:
      UT                   UT          PST                 Duration Round-trip     
DOY   Date                 TX Window   TX Window           hh:mm    time (sec)   SNR/run
70    Mar 11    2004 FX31  1215-1415   0415-0615 Mar 11     2:00        93          2     Overlaps 2021 EB1 and 2021 CF6

We could start FX31 as early as 11:40 if we're ready.

Overlap with 2021 EB1: 1100-1215 (nearly the entire track, including most of precal time)
Overlap with 2021 CF6: 1355-1215 (only 20 minutes at the end)



Uncertainties

2004 FX31
JPL/Horizons solution 151,  # obs: 758 (1990-2020)
Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta   POS_3sigma DOP_X_3sig  RT_delay_3sig
 2021-Mar-05 00:00 *   319.46946 -20.98916 0.11126523583960      2.692       10.15       0.000221
 2021-Mar-06 00:00 *   316.31956 -17.62939 0.10602607398963      2.777       10.63       0.000303
 2021-Mar-07 00:00 *   313.02906 -13.88338 0.10153819686197      2.832       10.92       0.000399
 2021-Mar-08 00:00 *   309.61239  -9.77211 0.09788754951301      2.847       10.94       0.000500
 2021-Mar-09 00:00 *   306.08767  -5.34565 0.09515360196136      2.814       10.62       0.000603
 2021-Mar-10 00:00 *   302.47644  -0.68519 0.09340065834556      2.731        9.93       0.000703
 2021-Mar-11 00:00 *   298.80309   4.10119 0.09266907985619      2.602        8.88       0.000794
 2021-Mar-12 00:00 *m  295.09394   8.88964 0.09296871153850      2.438        7.56       0.000874
 2021-Mar-13 00:00 *m  291.37627  13.55626 0.09427661202292      2.254        6.10       0.000941
 2021-Mar-14 00:00 *m  287.67707  17.99289 0.09653991130834      2.069        4.65       0.000992
 2021-Mar-15 00:00 *m  284.02199  22.11830 0.09968286606601      1.896        3.34       0.001029


2021 EB1
JPL/Horizons solution 4, # obs: 82 (27 days)
2021 Mar  9
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_X_3sig  RT_delay_3sig
 2021-Mar-07 00:00 *   207.45592  68.48129 0.04180774651882      0.611      895.91       0.052553
 2021-Mar-08 00:00 *   227.79873  69.31730 0.03489315151809      0.767      817.08       0.043963
 2021-Mar-09 00:00 *   255.19676  66.33018 0.02880978544169      1.236      679.71       0.036423
 2021-Mar-10 00:00 *   280.13723  56.25952 0.02419552044379      2.497      442.16       0.030720
 2021-Mar-11 00:00 *   296.71791  39.00705 0.02200019182290      4.641       86.46       0.028003 *
 2021-Mar-12 00:00 *m  306.93569  19.27011 0.02293599794439      6.386      304.19       0.029131
 2021-Mar-13 00:00 *m  313.48839   2.76775 0.02668240831165      6.753      596.69       0.033733
 2021-Mar-14 00:00 *m  317.95170  -8.89866 0.03228193818500      6.340      773.55       0.040656

JPL/Horizons solution 3, # obs: 67 (25 days)
2021 Mar 8
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_X_3sig  RT_delay_3sig
 2021-Mar-07 00:00 *   207.45587  68.48129 0.04181002185062      0.818     1003.75       0.060942
 2021-Mar-08 00:00 *   227.79824  69.31730 0.03489518698586      3.748      918.55       0.051334
 2021-Mar-09 00:00 *   255.19569  66.33041 0.02881158690499     10.364      773.57       0.042846
 2021-Mar-10 00:00 *   280.13602  56.26032 0.02419708094682     22.369      530.71       0.036250
 2021-Mar-11 00:00 *   296.71689  39.00858 0.02200149197717     37.230      200.49       0.032704 *
 2021-Mar-12 00:00 *m  306.93487  19.27200 0.02293706399428     44.454      315.16       0.033274
 2021-Mar-13 00:00 *m  313.48772   2.76949 0.02668335705015     41.029      631.21       0.037848
 2021-Mar-14 00:00 *m  317.95114  -8.89723 0.03228290509282     34.075      838.97       0.045224


Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: 2004 FX31 JPL/Horizons solution 151 Date__(UT)__HR:MN R.A._(a-appar)_DEC. APmag delta S-O-T /r T-O-M/MN_Illu% 2021-Mar-01 00:00 330.50019 -30.81462 22. 0.13811985880042 25.6406 /L 136.9/ 95.9292 2021-Mar-02 00:00 327.98605 -28.84740 21. 0.13066541299486 25.8860 /L 122.1/ 90.2151 2021-Mar-03 00:00 325.30828 -26.57500 21. 0.12366108731880 26.5647 /L 106.7/ 82.3440 2021-Mar-04 00:00 322.46809 -23.96491 21. 0.11717028067427 27.7727 /L 90.9/ 72.8110 2021-Mar-05 00:00 319.46946 -20.98916 20. 0.11126523583528 29.5893 /L 74.9/ 62.1991 2021-Mar-06 00:00 316.31956 -17.62939 20. 0.10602607398315 32.0631 /L 59.1/ 51.1139 2021-Mar-07 00:00 313.02906 -13.88338 19. 0.10153819685326 35.2030 /L 43.7/ 40.1344 2021-Mar-08 00:00 309.61239 -9.77211 19. 0.09788754950204 38.9741 /L 29.8/ 29.7847 2021-Mar-09 00:00 306.08767 -5.34565 18. 0.09515360194818 43.2991 /L 20.9/ 20.5187 2021-Mar-10 00:00 302.47644 -0.68519 18. 0.09340065833029 48.0634 /L 23.5/ 12.7118 2021-Mar-11 00:00 298.80309 4.10119 17. 0.09266907983903 53.1242 /L 34.8/ 6.6534 2021-Mar-12 00:00 295.09394 8.88964 16.942 0.09296871151972 58.3246 /L 48.6/ 2.5401 2021-Mar-13 00:00 291.37627 13.55626 16.629 0.09427661200282 63.5112 /L 62.7/ 0.4709 2021-Mar-14 00:00 287.67707 17.99289 16.386 0.09653991128726 68.5502 /L 76.2/ 0.4493 2021-Mar-15 00:00 284.02199 22.11830 16.206 0.09968286604424 73.3382 /L 88.6/ 2.3931 2021-Mar-16 00:00 280.43426 25.88247 16.079 0.10361594726142 77.8067 /L 99.4/ 6.1511 2021-Mar-17 00:00 276.93400 29.26459 15.996 0.10824465998222 81.9196 /L 108.3/ 11.5246 2021-Mar-18 00:00 273.53775 32.26712 15.948 0.11347654394745 85.6668 /L 114.7/ 18.2868 2021-Mar-19 00:00 270.25826 34.90870 15.929 0.11922580137544 89.0567 /L 118.3/ 26.1979 2021-Mar-20 00:00 267.10463 37.21752 15.931 0.12541574475967 92.1096 /L 118.9/ 35.0113 2021-Mar-21 00:00 264.08254 39.22620 15.950 0.13197960620416 94.8519 /L 116.8/ 44.4709 2021-Mar-22 00:00 261.19471 40.96822 15.982 0.13886029351020 97.3123 /L 112.4/ 54.2992 2021-Mar-23 00:00 258.44139 42.47571 16.024 0.14600957011723 99.5196 /L 106.4/ 64.1801 2021-Mar-24 00:00 255.82078 43.77826 16.072 0.15338698985400 101.5010 /L 99.3/ 73.7394 2021-Mar-25 00:00 253.32958 44.90237 16.127 0.16095878985783 103.2814 /L 91.7/ 82.5316 2021-Mar-26 00:00 250.96336 45.87133 16.185 0.16869685272580 104.8831 /L 84.0/ 90.0452 2021-Mar-27 00:00 248.71691 46.70542 16.247 0.17657778931917 106.3261 /L 76.8/ 95.7364 2021-Mar-28 00:00 246.58452 47.42209 16.310 0.18458215775619 107.6279 /L 70.6/ 99.0980 2021-Mar-29 00:00 244.56024 48.03633 16.375 0.19269381327685 108.8036 /L 66.3/ 99.7543 2021-Mar-30 00:00 242.63804 48.56093 16.440 0.20089937191371 109.8667 /L 64.2/ 97.5522 2021-Mar-31 00:00 240.81197 49.00677 16.506 0.20918776561616 110.8289 /L 64.8/ 92.6103 2021 EB1 JPL/Horizons solution 3 Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-brt S-O-T /r T-O-M/MN_Illu% 2021-Mar-05 00:00 186.82822 64.55614 0.05690939399493 19.388 n.a. 119.6105 /L 92.6/ 62.1001 2021-Mar-06 00:00 194.74266 66.57219 0.04921764032061 19.170 n.a. 116.1044 /L 99.3/ 50.8328 2021-Mar-07 00:00 207.41026 68.53516 0.04182096764278 18.953 n.a. 111.4626 /L 103.1/ 39.7003 2021-Mar-08 00:00 227.79497 69.38496 0.03490592754384 18.762 n.a. 105.0417 /L 102.6/ 29.2547 2021-Mar-09 00:00 255.26938 66.40730 0.02882149461074 18.664 n.a. 95.8323 /L 96.3/ 19.9649 2021-Mar-10 00:00 280.24845 56.33734 0.02420492005123 18.822 n.a. 82.6751 /L 82.9/ 12.2068 2021-Mar-11 00:00 296.82245 39.08255 0.02200547010493 19.517 n.a. 65.9065 /L 63.7/ 6.2572 2021-Mar-12 00:00 307.02340 19.33784 0.02293614958094 21. n.a. 49.9428 /L 45.8/ 2.2907 2021-Mar-13 00:00 313.56128 2.82286 0.02667826951910 22. n.a. 40.0677 /L 38.9/ 0.3795 2021-Mar-14 00:00 318.01318 -8.85527 0.03227495242648 23. n.a. 36.4848 /L 43.9/ 0.5010 2021-Mar-15 00:00 321.21414 -16.79169 0.03894096426468 24. n.a. 36.3617 /L 54.1/ 2.5512 2021-Mar-16 00:00 323.62106 -22.28553 0.04622185750537 24. n.a. 37.5552 /L 65.6/ 6.3649

Setups


2004 FX31:
The rotation period is unknown, but if this object has a period of 2.2 h or slower,
which is very likely, then the bandwidth will be less than about 32 Hz for an equatorial view.

2021 EB1:
The rotation period and diameter are unknown.  If we assume D = 0.06 km and P = 0.5 h,
then B = 12 Hz for an equatorial view.

The CW setup below should be a good starting point for both asteroids.

CW setup:
---------------------------------------------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           no hopping
Bandwidth:               5000 Hz 
TXoffset                 +500 Hz
FFT                      1000 for 5.0 Hz resolution 

Ranging setups:
---------------------------------------------------------------------------
10-usec
baud             10 usec
code            127
PRP            1270 usec
ncoh              1 
bandwidth       787 Hz   
FFT             128
resolution       6.15 Hz
TXoffset       +100 Hz  (echo in column 80)
---------------------------------------------------------------------------
11-usec 
baud             11 usec
code            127
PRP            1397 usec
ncoh              1 
bandwidth       716 Hz   
FFT             128
resolution      5.6 Hz
TXoffset     +100 Hz  (echo in column 82) 
-------------------------------------------------------------------------
1-usec 
baud              1 usec
code            255
ncoh              8
bandwidth       245 Hz   
FFT             128
resolution        3.8 Hz
TXoffset        +50 Hz  (echo in column 116)
---------------------------------------------------------------------

Instructions

NOTE: Data should be moved to the appropriate subdirectories in aardvark:/export/data0/2004fx31/raw/

POINTING:

  OSOD and predicts are on aardvark:



POINTING  

...Not yet available...

Transmit offsets are given in millidegrees.  


PRDX.OUT.14f-14-14.s?? TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL

2004 FX31 GOLDSTONE MASTERLOG

============================================================================== ----------------------------------------------------- ...Not yet available... -----------------------------------------------------
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/2004FX31/2004FX31.goldstone.planning.html

Asteroid Radar Astronomy
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