Goldstone Radar Observations Planning: (456537) 2004 FX31


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 April, so it is unlikely 
that lightcurves will provide the rotation period before the radar observations. 


Orbital and Physical Characteristics  
Name                     2004 FX31                 
Asteroid number          271480                    
Discoverer               LONEOS      
Discovery date           2004 Mar 31               
orbit type               Apollo                      
Close approach distance  0.093 au                  
Close approach date      2021 Mar 11               

semimajor axis           1.261 au                  
eccentricity             0.44                      
inclination              24.8 deg                  
Orbital period           1.42 years                
perihelion distance      0.703 au                  
aphelion distance        1.818 au                  
MOID                     0.066 au                  

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

Last update: 2021 February 23


Discovery M.P.E.C.


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


Track Assignments


DOY    BOA   BOT   EOT   EOA
70     1045  1215  1415  1445  GSSR AST 2004 FX31
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 CF6

...Daylight Saving Time starts on March 14...



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


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

Setups




CW setup:
---------------------------------------------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           no hopping
Bandwidth:               5000 Hz 
TXoffset                 +500 Hz
FFT                      5000 for 1.0 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
*************************************************************************************************************