2002 TD66 Goldstone Radar Observations Planning
Background
2002 TD66 was discovered by LINEAR on October 5, 2002.
It will approach within 0.0428 AU (16.7 lunar distances) on February 26 when it
will be a moderately strong radar target at Goldstone.
Goldstone observations are scheduled for one track that straddles the
date boundary on February 23-24. Arecibo observations are scheduled on February 23-25.
With an absolute magnitude of 19.9, 2002 TD66 has a diameter that is probably
within a factor of two of 330 meters. Otherwise, we know nothing about its
physical properties, but if recent experience is a guide, then there's a ~1/6 chance that
it's a binary object.
This object will brighten to about 15th magnitude in late February and
early March when it will be a good target for photometric observations.
Due to its diameter and the proximity of its orbit to Earth, 2002 TD66 has been
classified as a "Potentially Hazardous Asteroid" by the Minor Planet Center.
Orbital and Physical Characteristics
orbit type Apollo
semimajor axis 1.855 AU
eccentricity 0.534
inclination 4.9°
perihelion distance 0.864 AU
aphelion distance 2.846 AU
absolute magnitude (H) 19.9
diameter 330 meters +- a factor of two
rotation period unknown
pole direction unknown
lightcurve amplitude unknown
spectral class unknown
Last update: 2008 February 26
Discovery
M.P.E.C. 2002-T39 Issued 2002 Oct. 7, 20:34 UT
The Minor Planet Electronic Circulars contain information on unusual
minor planets and routine data on comets. They are published
on behalf of Commission 20 of the International Astronomical Union by the
Minor Planet Center, Smithsonian Astrophysical Observatory,
Cambridge, MA 02138, U.S.A.
Prepared using the Tamkin Foundation Computer Network
MPC@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html ISSN 1523-6714
2002 TD66
Observations:
K02T66D* C2002 10 05.25042 23 42 09.95 +08 45 08.8 19.6 704
K02T66D C2002 10 05.26606 23 42 07.39 +08 45 07.1 19.8 704
K02T66D C2002 10 05.29720 23 42 02.31 +08 45 09.5 19.7 704
K02T66D C2002 10 05.31273 23 41 59.80 +08 45 10.9 19.5 704
K02T66D C2002 10 06.27525 23 39 31.79 +08 46 07.0 19.4 R 651
K02T66D C2002 10 06.27762 23 39 31.39 +08 46 07.1 19.3 R 651
K02T66D C2002 10 06.27955 23 39 31.09 +08 46 07.4 19.6 R 651
K02T66D C2002 10 06.31719 23 39 24.64 +08 46 06.2 18.5 R 649
K02T66D C2002 10 06.32587 23 39 23.23 +08 46 06.2 18.5 R 649
K02T66D C2002 10 06.32977 23 39 22.58 +08 46 06.8 18.3 R 649
K02T66D C2002 10 07.11946 23 37 20.10 +08 46 46.3 18.8 R 649
K02T66D C2002 10 07.12427 23 37 19.34 +08 46 46.2 18.5 R 649
K02T66D C2002 10 07.12812 23 37 18.71 +08 46 46.6 18.5 R 649
Observer details:
649 Powell Observatory, Louisburg. Observers K. Smalley, R. Fredrick.
0.75-m Newtonian + CCD.
651 Grasslands Observatory, Tucson. Observer J. E. McGaha. 0.62-m f/5.1
reflector + CCD.
704 Lincoln Laboratory ETS, New Mexico. Observers M. Blythe, F. Shelly,
M. Bezpalko, R. Huber, L. Manguso, S. Adams, D. Torres, T. Brothers,
S. Partridge. Measurers J. Stuart, R. Sayer, J. B. Evans, H. Viggh. 1.0-m
f/2.15 reflector + CCD.
Orbital elements:
2002 TD66 PHA 0.003
Epoch 2002 Sept. 23.0 TT = JDT 2452540.5 MPC
M 320.32985 (2000.0) P Q
n 0.40855043 Peri. 126.02425 -0.18197224 -0.98271501
a 1.7987560 Node 334.39721 +0.87494374 -0.14603366
e 0.5163000 Incl. 4.51527 +0.44873104 -0.11377775
P 2.41 H 20.2 G 0.15
From 13 observations 2002 Oct. 5-7.
Ephemeris:
2002 TD66 a,e,i = 1.80, 0.52, 5 q = 0.8701
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2002 10 03 23 47.74 +08 42.6 0.363 1.357 167.2 9.4 19.3
2002 10 13 23 21.05 +08 49.6 0.309 1.280 152.6 21.0 19.2
2002 10 23 22 51.18 +08 49.3 0.269 1.203 136.1 35.0 19.2
2002 11 02 22 20.93 +08 53.8 0.238 1.129 119.5 50.0 19.2
2002 11 12 21 51.34 +09 15.8 0.211 1.058 103.1 65.7 19.3
2002 11 22 21 19.30 +10 00.0 0.184 0.994 86.5 82.8 19.4
2002 12 02 20 36.32 +10 43.4 0.156 0.939 68.3 102.9 19.8
2002 12 12 19 29.97 +10 06.6 0.133 0.899 46.7 127.1 21.0
Timothy B. Spahr (C) Copyright 2002 MPC M.P.E.C. 2002-T39
SNR Calculation
HMag: 19.9
Diameter: 0.33 km (an educated guess assuming H = 17.8 and an S-class optical albedo)
Period: 4 (a standard guess)
------------GOLDSTONE---------- -------------ARECIBO-----------
Max Max
Dat Run UTC Dat Run UTC
Date RA Decl Delta Runs SNR SNR Window Runs SNR SNR Window
2008 2 21 36 26 0.056 329 59 4 18:41-29:41 76 1200 150 19:30-22:06
2008 2 22 43 27 0.052 357 82 5 19:00-30:06 81 1700 200 20:00-22:30
2008 2 23 51 28 0.048 385 110 6 19:30-30:36 85 2300 260 20:30-22:53
2008 2 24 60 28 0.045 407 150 8 20:00-31:11 89 2900 330 21:00-23:30
2008 2 25 71 28 0.043 422 170 9 20:41-31:48 93 3500 390 21:41-24:11
2008 2 26 82 26 0.042 424 190 10 21:23-32:30 97 3800 410 22:18-24:53
2008 2 27 93 24 0.042 412 180 10 22:11-33:00 99 3700 390 22:53-25:36
2008 2 28 103 21 0.044 390 150 8 22:53-33:30 98 3200 340 23:30-26:11
2008 2 29 111 18 0.047 361 110 7 23:30-33:53 92 2500 270 0:00- 2:47
2008 3 1 119 16 0.051 330 83 5 0:06-10:11 85 1800 210 0:30- 3:06
2008 3 2 125 13 0.056 300 59 4 0:36-10:24 77 1300 150 0:54- 3:23
Track Assignments
2002 TD66 Goldstone Schedule
UT UT PST Duration Round-trip
DOY Date TX Window TX Window hh:mm time (sec)
--- ---- --------- --------- ------- ---------
054-055 Feb 23-24 2310-0200 1510-1800 Feb 23 02:50 46
Arecibo Schedule
054 Feb 23 2057-2330 1257-1530 Feb 23 02:33 45
055-056 Feb 24-25 2136-0010 1336-1610 Feb 24 02:34 43
056-057 Feb 25-26 2215-0055 1415-1655 Feb 25 02:40 42
Uncertainties
From Horizons, 2008 February 08
Date__(UT)__HR:MN R.A._(J2000.0)_DEC. delta POS_3sigma DOP_X-sig RT_delay-sig
2008-Feb-22 00:00 42.62930 26.62147 0.052737965609842 7.69767680 3.36 0.009735
2008-Feb-23 00:00 50.56118 27.41467 0.048790146174228 11.0439877 2.21 0.009535
2008-Feb-24 00:00 59.80989 27.76373 0.045701435155892 16.2032033 1.52 0.009163
2008-Feb-25 00:00 70.15643 27.42402 0.043656791756980 22.4381148 2.41 0.008569
2008-Feb-26 00:00 81.06487 26.22890 0.042810003692392 28.6117121 4.04 0.007737
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Jon Giorgini, 2008 February 19:
With 95 optical measurements 2002-Oct-5 to 2008-Feb-18, 2002 TD66
solution #29 was estimated. Formal 3-sigma S-band uncertainties are
shown below.
Date__(UT)__HR:MN POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2008-Feb-22 00:00 6.32809000 0.94 3.36 0.006387
2008-Feb-23 00:00 9.53907357 0.72 2.58 0.006138
2008-Feb-24 00:00 13.4990423 0.48 1.73 0.005762
2008-Feb-25 00:00 17.7894127 0.31 1.12 0.005230
2008-Feb-26 00:00 21.6976134 0.42 1.49 0.004543
2008-Feb-27 00:00 24.4633891 0.68 2.42 0.003745
Setups
We don't know the rotation period or the bandwidth, so we'll start with a standard CW
setup in the hope that it shows an echo quickly and also resolves it in frequency:
Initial CW setup
----------------
TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: 2
Dwell 20 seconds
Bandwidth: 4000 Hz
Sampling interval: 2500 x 0.1 usec
VME FFT for PSD files: 4096 for 0.98-Hz resolution
Possible ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
PRP 1270 usec
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 787.4 Hz
resolution 12.3 Hz
TXOFF +100 Hz -> echo will be centered at +8 bins or in bin 32 + 8 = 40
---------------------------------------------------------------------------
127 x 64 11-usec single sample
baud 11 usec
code 127
gates 127
PRP 1397 usec
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 715.8 Hz
resolution 11.2 Hz
TXOFF +100 Hz --> echo will be centered at +9 bins or in bin 32 + 9 = 41
-------------------------------------------------------------------------
127 x 64 7-usec single sample
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 1124.9 Hz
resolution 17.6 Hz
TXOFF +60 -> echo would be centered at +3.4 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 1-usec single sample
baud 1 usec
code 127
gates 127
PRP 127
FFT 64
CLT 4
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +100 -> echo would be centered at +12.2 bins or in bin 32 + 12.2 = 44
-------------------------------------------------------------------------------
0.125-usec ranging
setup JX1XS001 revised
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 984
bandwidth 64.016384 Hz
resolution 1.000256 Hz
TXOFF +15 Hz to put echo at 32 + 15 = bin 47
PFS CLT gate ?
VME CLT gate ?
_______________________________________________________________________
POSSIBLE RANGING SETUPS: (code=127, FFT=64, single-pol'n)
These are from JX, w/ max-band (min-acc) options from Ray Jurgens.
Currently configured for 5-sec records.
_______________________________________________________________________
Setup Baud RP 1-acc 1-acc
usec m usec band res acc band res
_______________________________________________________________________
JX1XS110 11.000 1650 1397.0 715.8 11.2 2 358 5.6
JX1XS070 7.000 1050 889.0 1124.9 17.6 3 375 5.9
JX1XS020 2.000 300 254.0 3937.0 61.5 12 328 5.1
4 984 15.4
JX1XS010 1.000 150 127.0 7874.0 123.0 41 192 3.0
8 984 15.4
JX1XS005 0.500 75 63.5 15748.0 246.1 123 128 2.0
15 1050 16.4
JX1XS002 0.250 37.5 31.75 31496.1 492.1 492 64 1.0
30 1050 16.4
JX1XS001 0.125 18.75 15.875 62992.1 984.3 1970 32 0.5
60 1050 16.4
______________________________________________________________________
Instructions
NOTE: Data should be moved to the appropriate subdirectories in
aardvark:/export/data0/2002TD66/
2002 TD66 POINTING:
OSOD and predicts are at Goldstone on aardvark:
/export/data3/ops/2002td66/ PRDX.OUT.s29
/PUNCH.OUT.s29
/EPH.OUT.s29
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2008 02 23 054 230000 59.5375 27.7845 A 29
2008 02 24 055 000000 59.9365 27.7894 A
2008 02 24 055 010000 60.3361 27.7918 A -0.0050 0.0000
2008 02 24 055 020000 60.7370 27.7917 A
2008 02 24 055 030000 61.1402 27.7891 A
PRDX.OUT.s29
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2008 FEB 23 23:10 45.7008084142 271412.078 324.2278 27.7855 59.604 58.773
2008 FEB 23 23:20 45.6818320231 270044.181 326.6682 27.7864 59.670 60.755
2008 FEB 23 23:30 45.6629522086 268656.838 329.1085 27.7873 59.737 62.730
2008 FEB 23 23:40 45.6441702817 267251.270 331.5489 27.7880 59.803 64.697
2008 FEB 23 23:50 45.6254874670 265828.727 333.9892 27.7887 59.870 66.652
2008 FEB 24 00:00 45.6069049367 264390.493 336.4295 27.7894 59.937 68.589
2008 FEB 24 00:10 45.5884237176 262937.875 338.8698 27.7900 60.003 70.504
2008 FEB 24 00:20 45.5700447895 261472.205 341.3101 27.7905 60.070 72.387
2008 FEB 24 00:30 45.5517690104 259994.840 343.7504 27.7909 60.136 74.225
2008 FEB 24 00:40 45.5335971522 258507.152 346.1906 27.7913 60.203 76.001
2008 FEB 24 00:50 45.5155298988 257010.533 348.6308 27.7916 60.269 77.685
2008 FEB 24 01:00 45.4975678178 255506.388 351.0710 27.7918 60.336 79.235
2008 FEB 24 01:10 45.4797113870 253996.136 353.5112 27.7920 60.403 80.581
2008 FEB 24 01:20 45.4619609844 252481.204 355.9512 27.7921 60.470 81.626
2008 FEB 24 01:30 45.4443168970 250963.025 358.3913 27.7921 60.536 82.245
2008 FEB 24 01:40 45.4267792930 249443.037 0.8313 27.7921 60.603 82.333
2008 FEB 24 01:50 45.4093482576 247922.680 3.2712 27.7919 60.670 81.875
2008 FEB 24 02:00 45.3920237573 246403.393 5.7111 27.7917 60.737 80.952
2002 TD66 GOLDSTONE MASTERLOG
==============================================================================
Receive TX
Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes
------------------------------------------------------------------------------
2008 February 23-24
PSD2008.054.233.2002TD66, VOLT2008.054.234.2002TD66
CW, 4 kHz 2 20 4096 7 233705-234715 29 none RCP Transmitter leakage?
We had problems with the VME and PFS during this set. There's one more run
in the data files than indicated in the tx/rcv log, possibly because we
kept going briefly when the quasi-optical mirror hung.
PSD2008.055.236.2002TD66, VOLT2008.055.237.2002TD66
CW, 4 kHz 2 20 4096 4 000905-001436 29 none LCP Transmitter leakage?
PSD2008.055.238.2002TD66, VOLT2008.055.239.2002TD66
CW, 4 kHz 2 20 8192 22 001524-004903 29 none LCP
PSD2008.055.240.2002TD66, VOLT2008.055.241.2002TD66
CW, 4 kHz 2 20 8192 44 005124-015938 31 none LCP
Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 300-233 | FAX: (818) 354-9476
Jet Propulsion Laboratory | email: lance@reason.jpl.nasa.gov
Pasadena, CA 91109-8099 | Plan: To live long and prosper
http://echo.jpl.nasa.gov/asteroids/2002TD6/2002TD66_planning.html
Asteroid Radar Astronomy