Goldstone Radar Observations Planning: (231937) 2001 FO32


Background


2001 FO32    
(231937) 2001 FO32 was discovered on March 23, 2001 by LINEAR, and on March 21, it will approach
within 0.0135 au (5.3 lunar distances).  During this encounter, the asteroid will brighten to about
12th magnitude when it should be visible for experienced observers with small telescopes.

NEOWISE spacecraft data (Ned Wright, pers. comm.) indicate that 2001 FO32 is about 0.6 km in diameter.
Given the asteroid's absolute magnitude of 17.7, the diameter corresponds to an optical albedo of about
0.5, which is exceptionally bright. 
Lightcurves obtained by Petr Pravec (pers. comm.) reveal that 2001 FO32 is a slow, non-principal axis
rotator with a fundamental period of 40 hours and a second period of roughly 53 hours.  The lightcurve
amplitude is 0.9 magnitudes and probably indicates that the shape is very elongated. 

The asteroid will approach from the south and enter Goldstone's declination window on March 21
shortly before the time of closest approach.  The 70 m DSS-14 antenna at Goldstone is offline
for maintenance and will not be able to observe 2001 FO32 with radar, but we have scheduled
time on the 34 m DSS-13 antenna and the 100 m Green Bank Telescope on March 22, when the radar
signal-to-noise ratios should still be strong enough for delay-Doppler imaging.

2001 FO32 has an unusually high orbital eccentricity and a perihelion distance of only 0.3 au,
which is inside the average distance of Mercury from the Sun. The aphelion is at 3.1 au and is 
deep within the outer main asteroid belt.  The orbit also has a steep 39 degree inclination.

The asteroid will move rapidly across the sky during the encounter and will become a daytime object
on March 22. 

2001 FO32 makes relatively frequent close approaches within 0.1 au of Earth, Venus, and Mercury.
The 2021 encounter is the closest with Earth for at least the next few centuries.


Goldstone DSS-13 > Green Bank Bistatic Radar Images of Asteroid (231937) 2001 FO32


Delay-Doppler radar images of 2001 FO32 obtained on March 22 by transmitting with the 34 meter
DSS-13 antenna at Goldstone and receiving with the 100 meter Green Bank Telescope 
in West Virginia.  Resolution is 37.5 m x 0.1 Hz.  In each panel, range increases
down and Doppler frequency increases to the left, so the illumination comes from the
top and rotation is clockwise.  In the collage, time increases from the top left
panel to the lower left panel, etc., so the last frame in the sequence is at the lower 
right.  Each image is an integration spanning five minutes with a ten minute gap 
between frames.  The sequence of images spans about 110 minutes.  

The images reveal that 2001 FO32 is elongated and shaped somewhat like a peanut with a
long axis of about 1.2 km.  The rotation evident in the images is consistent with the 
40 h principal rotation period reported by Petr Pravec et al.  The long axis is larger
than the diameter estimated from NEOWISE data, so it's possible (and perhaps probable)
that NEOWISE observed the asteroid when it was closer to an end-on orientation than 
the broadside orientation seen in the radar images.



Orbital and Physical Characteristics  
Name                     2001 FO32
Asteroid number          231937
Discoverer               LINEAR              
Discovery date           2001 March 23
orbit type               Apollo                         
Close approach distance  0.0135 au  (5.25 lunar distances)
Close approach date      2021 Mar 21                    

semimajor axis           1.701 au                      
eccentricity             0.826                         
inclination              38.9 deg                      
Orbital period           2.219 years                    
perihelion distance      0.296 au       
aphelion distance        3.106 au                      
MOID                     0.049 au                      

absolute magnitude (H)   17.7
diameter                 0.56 km         (Ned Wright, pers. comm., NEOWISE data)    
optical albedo           0.48            (Ned Wright, pers. comm., NEOWISE data)    
rotation period          39.89 +-0.06 h  (P. Pravec, pers. comm.)
lightcurve amplitude     0.9 mag         (P. Pravec, pers. comm.)
pole direction           NPA
spectral class           unknown                       
PHA?                     Yes

Last update: 2021 April 9


Discovery M.P.E.C.


2001 FO32
https://www.minorplanetcenter.net/mpec/K01/K01F32.html


SNR Calculations

Goldstone SNRs
2001 FO32:  D = 0.6 km,  P = 39.89 h,  OC albedo = 0.1
                    20 deg horizons                        Monostatic DSS-14  DSS13>GBT
DOY    start date       window       RA, dec   dist   runs  SNR/day SNR/run    SNR/RTT
80    2021 Mar 21     13:25-19:56   302, -23  0.013    733   91000    3600      290    Scheduled at Canberra and ATCA
81-82 2021 Mar 22-23  13:43-00:11   346, +14  0.026    695   11000     430       34    Scheduled at DSS-13 and GBT
82-83 2021 Mar 23-24  14:06-01:01   357, +22  0.045    434    1200      64        5
83-84 2021 Mar 24-25  14:14-01:21     2, +26  0.064    310     290      18        1
84-85 2021 Mar 25-26  14:18-01:30     5, +27  0.084    240     100       7
85-86 2021 Mar 26-27  14:18-01:35     6, +28  0.104    195      43       3
86-87 2021 Mar 27-28  14:18-01:36     8, +29  0.124    165      22       2

With a 40 h rotation period, imaging integrations spanning one hour 
will show only 9 degrees of rotation.


Track Assignments


DOY    BOA   BOT   EOT   EOA
81           1330  1705  1735  DSSR AST 2001 FO32   

Goldstone tracks:
      UT       UT          PDT                 Duration Round-trip     
DOY   Date     TX Window   TX Window           hh:mm    time (sec)  
81    Mar 22   1330-1705   0630-1005 Mar 11     3:35       23

The DSS-13 BOT time occurs at an elevation of about 18 deg, so we
may need to transmit less than 80 kW initially. 

Elevations (degrees) early in the track:
Time  DSS-13   GBT
12:45   8.6    37.4
13:00  11.6    40.1
13:15  14.6    42.8
13:30  17.6    45.4
13:45  20.6    47.9

GBT schedule: 1300-1715 UT (0600-1015 PDT)



Uncertainties

2001 FO32
JPL/Horizons solution 60, # obs: 202 (2001-2021)
2021 Mar 19
Note: C-band Doppler uncertainties are about (0.84)x X-band uncertainties.
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-18 00:00 *m  205.31643 -36.47676 0.07418195411994      1.798        0.95        3.47       0.000790
 2021-Mar-19 00:00 *m  209.77897 -37.85444 0.05474554860309      2.576        1.63        5.91       0.000775
 2021-Mar-20 00:00 *m  219.50086 -40.11698 0.03581916257311      4.331        4.04       14.69       0.000730
 2021-Mar-21 00:00 *m  250.38162 -41.49152 0.01895646322420      9.877       17.73       64.44       0.000555
 2021-Mar-22 00:00 *m  321.20329  -7.78483 0.01501778725967     10.866       23.88       86.78       0.000735
 2021-Mar-23 00:00 *m  349.33447  16.61405 0.02969681735565      4.034        4.11       14.92       0.000931
 2021-Mar-24 00:00 *m  358.43935  23.19717 0.04826952879827      2.519        1.63        5.93       0.000947
 2021-Mar-25 00:00 *m    2.68706  25.89305 0.06761997738471      1.876        0.97        3.54       0.000955

Hourly intervals on March 21:
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-21 12:00     286.98095 -31.72613 0.01387580748131     14.414       34.75      126.31       0.000457
 2021-Mar-21 13:00 N   290.33768 -30.05003 0.01369568759767     14.534       35.46      128.87       0.000468
 2021-Mar-21 14:00 *   293.64683 -28.24624 0.01356472453031     14.569       35.85      130.28       0.000484
 2021-Mar-21 15:00 *   296.88868 -26.33104 0.01348448177571     14.513       35.89      130.43       0.000503
 2021-Mar-21 16:00 *   300.04615 -24.32460 0.01345598924624     14.364       35.57      129.28       0.000526

Hourly intervals during the track on March 22:
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-22 13:00 N   340.98093   9.60609 0.02197533605794      5.797        8.16       29.67       0.000897
 2021-Mar-22 14:00 *   341.95875  10.45422 0.02262695207852      5.574        7.57       27.53       0.000902
 2021-Mar-22 15:00 *   342.88071  11.25134 0.02329011306759      5.367        7.04       25.60       0.000906
 2021-Mar-22 16:00 *   343.75117  12.00070 0.02396436799582      5.175        6.56       23.86       0.000910
 2021-Mar-22 17:00 *   344.57443  12.70537 0.02464928194251      4.996        6.13       22.29       0.000914
 2021-Mar-22 18:00 *   345.35463  13.36825 0.02534440243258      4.830        5.75       20.88       0.000917
The distance increases rapidly and, between 13:00-17:00, will reduce 
the SNR/RTT by about 37%.

- - - - - - - - - - 

JPL/Horizons solution 55, # obs: 187 (2001-2021)
2021 Feb 25
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-15 00:00 *m  199.97908 -34.48664 0.13340757508848      4.581        0.72        2.61       0.001981
 2021-Mar-16 00:00 *m  201.13311 -34.95640 0.11357781500801      5.481        1.09        3.96       0.001965
 2021-Mar-17 00:00 *m  202.77555 -35.58350 0.09382387924990      6.786        1.87        6.79       0.001928
 2021-Mar-18 00:00 *m  205.31652 -36.47674 0.07418196130758      8.838        3.49       12.70       0.001852
 2021-Mar-19 00:00 *m  209.77909 -37.85440 0.05474555733708     12.480        7.37       26.78       0.001692
 2021-Mar-20 00:00 *m  219.50105 -40.11691 0.03581917806821     20.308       19.49       70.85       0.001309
 2021-Mar-21 00:00 *m  250.38185 -41.49131 0.01895650357409     40.826       76.00      276.24       0.000636
 2021-Mar-22 00:00 *m  321.20310  -7.78469 0.01501786108083     19.463       39.33      142.93       0.003573
 2021-Mar-23 00:00 *m  349.33432  16.61407 0.02969687081035     11.511       10.81       39.28       0.003520
 2021-Mar-24 00:00 *m  358.43924  23.19719 0.04826957443379      9.402        5.04       18.33       0.003269
 2021-Mar-25 00:00 *m    2.68699  25.89306 0.06762002110188      7.462        2.30        8.35       0.003153

Uncertainties at hourly intervals on March 21:
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-21 12:00     286.98096 -31.72584 0.01387587345150     47.154      116.47      423.30       0.002138
 2021-Mar-21 13:00 N   290.33767 -30.04975 0.01369575545218     46.022      114.88      417.52       0.002304
 2021-Mar-21 14:00 *   293.64679 -28.24596 0.01356479409771     44.520      111.91      406.75       0.002467
 2021-Mar-21 15:00 *   296.88862 -26.33077 0.01348455285415     42.664      107.59      391.02       0.002624
 2021-Mar-21 16:00 *   300.04606 -24.32434 0.01345606160828     40.487      101.98      370.65       0.002775


Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: 2001 FO32 JPL/Horizons solution 60 Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-brt S-O-T /r T-O-M/MN_Illu% 2021-Mar-01 00:00 194.82260 -31.69416 0.41640994263004 17.831 3.762 129.8148 /L 36.3/ 96.1371 2021-Mar-02 00:00 195.01816 -31.83621 0.39585583476924 17.699 3.740 130.4554 /L 29.0/ 90.4644 2021-Mar-03 00:00 195.22040 -31.97993 0.37535618637630 17.562 3.718 131.0871 /L 27.3/ 82.5449 2021-Mar-04 00:00 195.43111 -32.12595 0.35491032662538 17.419 3.695 131.7085 /L 32.0/ 72.8856 2021-Mar-05 00:00 195.65251 -32.27509 0.33451757492694 17.268 3.673 132.3176 /L 40.8/ 62.1001 2021-Mar-06 00:00 195.88745 -32.42836 0.31417723471376 17.109 3.650 132.9122 /L 51.5/ 50.8328 2021-Mar-07 00:00 196.13955 -32.58708 0.29388858553939 16.942 3.627 133.4893 /L 62.9/ 39.7003 2021-Mar-08 00:00 196.41358 -32.75300 0.27365088096452 16.765 3.603 134.0452 /L 74.5/ 29.2547 2021-Mar-09 00:00 196.71583 -32.92841 0.25346336054402 16.576 3.580 134.5748 /L 86.1/ 19.9649 2021-Mar-10 00:00 197.05484 -33.11646 0.23332528640079 16.374 3.557 135.0716 /L 97.5/ 12.2068 2021-Mar-11 00:00 197.44243 -33.32146 0.21323602052385 16.157 3.534 135.5264 /L 108.6/ 6.2572 2021-Mar-12 00:00 197.89537 -33.54949 0.19319517124387 15.922 3.512 135.9264 /L 119.3/ 2.2907 2021-Mar-13 00:00 198.43836 -33.80939 0.17320286301167 15.665 3.490 136.2528 /L 129.3/ 0.3795 2021-Mar-14 00:00 199.10913 -34.11432 0.15326023906042 15.382 3.470 136.4770 /L 138.3/ 0.5010 2021-Mar-15 00:00 199.96845 -34.48482 0.13337043545259 15.066 3.452 136.5535 /L 145.8/ 2.5512 2021-Mar-16 00:00 201.12060 -34.95443 0.11354059438600 14.708 3.438 136.4045 /L 150.9/ 6.3649 2021-Mar-17 00:00 202.76051 -35.58144 0.09378643098761 14.294 3.431 135.8861 /L 152.8/ 11.7374 2021-Mar-18 00:00 205.29802 -36.47482 0.07414403649040 13.803 3.437 134.6992 /L 151.6/ 18.4440 2021-Mar-19 00:00 209.75592 -37.85348 0.05470670236993 13.199 3.469 132.1134 /L 148.9/ 26.2532 2021-Mar-20 00:00 219.47443 -40.12032 0.03577855042384 12.437 3.570 125.8294 /L 148.2/ 34.9318 2021-Mar-21 00:00 250.40262 -41.50477 0.01891441262244 11.668 3.935 105.1078 /L 159.7/ 44.2407 2021-Mar-22 00:00 321.33457 -7.69546 0.01500757528082 15. 6. 40.8645 /L 133.9/ 53.9226 2021-Mar-23 00:00 349.40192 16.65430 0.02971279450469 21. 9. 20.1809 /L 108.9/ 63.6834 2021-Mar-24 00:00 358.48045 23.21743 0.04829204767280 21. 8. 22.2886 /L 109.6/ 73.1709 2021-Mar-25 00:00 2.71624 25.90592 0.06764488144147 21. 8. 24.1339 /L 116.4/ 81.9587

Setups


2001 FO32:
For a rotation period of 40 h and a diameter of about 0.56 km, 
the bandwidth could be about 1 Hz for an equatorial view.
Lightcurve observations indicate that the shape is elongated, so the
bandwidth could be double or 1/2 of this value. 


CW setup:
--------------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           no hopping
Bandwidth:               5000 Hz 
TXoffset                 +500 Hz
FFT                     25000 for 0.2 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)
---------------------------------------------
1/4 usec
baud              0.25 usec
code            127
ncoh            500
bandwidth        63.0 Hz
FFT            1024
resolution        0.06 Hz
TXoffset        +10 Hz  
---------------------------------------------
1/8 usec
baud              0.125 usec
code            127 
ncoh           1000 
bandwidth        63.0 Hz
FFT            1024 
resolution        0.06 Hz
TXoffset        +10 Hz  
---------------------------------------------



Instructions

NOTE: Data should be moved to the appropriate subdirectories in aardvark:/export/data0/a231937/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

2001 FO32 GOLDSTONE MASTERLOG

============================================================================== ----------------------------------------------------- -----------------------------------------------------
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/2001FO32/2001FO32.2021.goldstone.planning.html

Asteroid Radar Astronomy
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