2006 AS2 Goldstone Radar Observations Planning


Background

2006 AS2 was discovered by the Mt. Lemmon Survey (Arizona) on January 5, 2006.
It will approach within 0.0235 AU (9.2 lunar distances) on February 10, 2009.

2006 AS2 has an absolute magnitude of 20.3, that, combined with its 
C-class taxonomy (M. D. Hicks et al., pers. comm.) suggests a diameter 
within a factor of two of 520 meters.   Brian Warner and Al Harris report 
a rotation period of 4.5 hours.

We are expecting this asteroid to be a strong target and we
hope to image it with 1/8 usec resolution.

Goldstone observations are scheduled on February 7 and 8.
Arecibo observations are scheduled on February 11-16.

This object will brighten to about 15th magnitude in early February when it will
be a good target for photometric and spectroscopic observations.

2006 AS2 has been classified as a "Potentially Hazardous Asteroid" by the 
Minor Planet Center.

Orbital and Physical Characteristics  
 orbit type               Apollo
 semimajor axis           2.093 AU     
 eccentricity             0.636
 inclination              2.6°       
 perihelion distance      0.762 AU     
 aphelion distance        3.424 AU     
 absolute magnitude (H)  20.3
 diameter               520 meters +- a factor of two
 rotation period          4.5 h   (B. D. Warner and A. W. Harris, pers. comm.)
 pole direction           unknown  
 lightcurve amplitude     0.2 mag (B. D. Warner and A. W. Harris, pers. comm.)
 spectral class           C       (M. D. Hicks, K. Lawrence, and B. Buratti, pers. comm.)

Last update: 2009 February 5

Discovery


M.P.E.C. 2006-A23                                Issued 2006 Jan. 6, 20:07 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.

                  Supported in part by the Brinson Foundation
                  Supported in part by the TABASGO Foundation
             Prepared using the Tamkin Foundation Computer Network

                              MPC@CFA.HARVARD.EDU
          URL http://cfa-www.harvard.edu/iau/mpc.html  ISSN 1523-6714

                                   2006 AS2

Observations:
     K06A02S* C2006 01 05.41164 10 23 57.62 +08 20 52.9          19.7 V EA023G96
     K06A02S  C2006 01 05.41895 10 23 59.60 +08 20 43.5          19.6 V EA023G96
     K06A02S  C2006 01 05.42625 10 24 01.58 +08 20 33.8          19.7 V EA023G96
     K06A02S  C2006 01 05.43361 10 24 03.56 +08 20 24.2          19.6 V EA023G96
     K06A02S  C2006 01 05.47599 10 24 15.08 +08 19 28.0          19.9 V EA023G96
     K06A02S  C2006 01 05.48596 10 24 17.74 +08 19 15.2          19.7 V EA023G96
     K06A02S  C2006 01 05.49605 10 24 20.48 +08 19 01.7          19.5 V EA023G96
     K06A02S  C2006 01 05.50598 10 24 23.22 +08 18 48.3          19.7 V EA023G96
     K06A02S  C2006 01 06.24034 10 27 55.24 +08 02 13.8          20.0 R EA023734
     K06A02S  C2006 01 06.24934 10 27 57.80 +08 02 00.8          19.7 R EA023734
     K06A02S  C2006 01 06.25834 10 28 00.47 +08 01 48.8          19.2 R EA023734
     K06A02S 5C2006 01 06.40116 10 28 41.83 +07 58 34.1          19.0 R EA023673
     K06A02S 5C2006 01 06.40417 10 28 42.69 +07 58 29.7                 EA023673
     K06A02S 5C2006 01 06.40938 10 28 44.17 +07 58 22.1                 EA023673
     K06A02S 5C2006 01 06.41551 10 28 45.99 +07 58 13.6                 EA023673
     K06A02S  C2006 01 06.46735 10 29 00.54 +07 57 02.3          19.9 V EA023G96
     K06A02S  C2006 01 06.47413 10 29 02.48 +07 56 52.4          19.8 V EA023G96
     K06A02S  C2006 01 06.48086 10 29 04.43 +07 56 42.9          19.7 V EA023G96

Observer details:
673 Table Mountain Observatory, Wrightwood.  Observer J. Young.  0.6-m f/16
    Cassegrain + CCD.
734 Farpoint Observatory.  Observer D. Tibbets.  0.7-m reflector + CCD.
G96 Mt. Lemmon Survey.  Observers R. A. Kowalski, E. J. Christensen.
    Measurers E. C. Beshore, E. J. Christensen, G. J. Garradd, A. D. Grauer,
    R. E. Hill, R. A. Kowalski, S. M. Larson, R. H. McNaught.  1.5-m reflector
    + CCD.

Orbital elements:
2006 AS2                                            PHA, Earth MOID = 0.0106 AU
Epoch 2006 Jan. 5.0 TT = JDT 2453740.5                  MPC
M 338.35061              (2000.0)            P               Q
n   0.32215817     Peri.   79.90612     -0.89685807     +0.44076481
a   2.1074468      Node   126.23705     -0.42167794     -0.82672106
e   0.6417071      Incl.    2.63211     -0.13354144     -0.34965507
P   3.06           H   20.2           G   0.15
From 18 observations 2006 Jan. 5-6.

Ephemeris:
2006 AS2                 a,e,i = 2.11, 0.64, 3                   q = 0.7551
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase     V
2006 01 05    10 22.05   +08 30.0    0.343    1.232   130.2    37.6    19.8
2006 01 15    11 23.73   +03 30.0    0.236    1.134   124.3    45.8    19.1
2006 01 25    13 21.33   -06 14.7    0.168    1.037   103.6    67.3    18.8
2006 02 04    16 07.97   -16 16.0    0.175    0.946    71.9    98.0    19.8
2006 02 14    18 04.58   -18 32.5    0.249    0.866    54.1   112.4    21.2

Gareth V. Williams           (C) Copyright 2006 MPC           M.P.E.C. 2006-A23


SNR Calculation

Target Name:    2006 AS2
HMag:           20.3
Diameter:       0.52 km  (an educated guess for its absolute magnitude and assuming a C-class optical albedo)
Period:         4.5 h    (B. D. Warner and A. W. Harris, pers. comm.)

Goldstone SNRs

                UTC          LST                            #           max
 start date    window       window      RA, dec   dist    runs   SNR  SNR/run
-----------------------------------------------------------------------------
2009 Feb 06  14:51-03:13  00:20-12:44   97,  35  0.041    432    470     26
2009 Feb 07  13:58-02:42  23:31-12:17   87,  39  0.034    516    990     47
2009 Feb 08  12:44-01:44  22:21-11:23   72,  43  0.028    611   2000     89
2009 Feb 09  11:07-00:04  20:47-09:46   50,  44  0.025    688   3400    140
2009 Feb 10  09:28-21:55  19:12-07:41   23,  41  0.024    689   4100    170
2009 Feb 11  08:23-19:58  18:11-05:48    2,  32  0.025    610   3000    130
2009 Feb 12  07:51-18:32  17:43-04:25  347,  22  0.030    503   1600     77
2009 Feb 13  07:35-17:32  17:30-03:29  338,  15  0.036    409    760     40
2009 Feb 14  07:27-16:48  17:26-02:49  333,   9  0.043    336    360     21

Goldstone SNRs assume Ptx = 430 kW 

 
Arecibo SNRs
                UTC          LST                            #           max
 start date    window       window      RA, dec   dist    runs   SNR  SNR/run
-----------------------------------------------------------------------------
2009 Feb 02  01:57-04:36  06:20-08:59  115,  25  0.080     54    340     49
2009 Feb 03  01:47-04:22  06:14-08:49  113,  26  0.071     58    530     73
2009 Feb 04  01:36-04:05  06:06-08:36  110,  28  0.063     63    860    110
2009 Feb 05  01:24-03:42  05:58-08:17  107,  30  0.054     66   1400    190
2009 Feb 06  01:11-03:10  05:49-07:49  102,  33  0.047     65   2300    310
2009 Feb 07  00:59-02:19  05:41-07:01   95,  36  0.039     51   3100    470
...too far north for Arecibo to track from Feb. 8-10...
2009 Feb 11  17:47-20:01  22:48-01:02  358,  30  0.026    121  26000   2400
2009 Feb 12  16:37-19:18  21:41-00:23  345,  21  0.031    126  14000   1400
2009 Feb 13  16:02-18:38  21:10-23:47  337,  14  0.037    104   7000    710
2009 Feb 14  15:45-18:03  20:57-23:16  332,   9  0.044     79   3300    390
2009 Feb 15  15:37-17:33  20:53-22:49  328,   5  0.052     58   1600    210
2009 Feb 16  15:35-17:05  20:55-22:25  325,   2  0.060     39    670    120 
2009 Feb 17  15:39-16:37  21:03-22:01  323,   0  0.068     22    270     61 

Arecibo SNRs assume Ptx = 700 kW.  


Track Assignments


Goldstone Schedule

         UT          UT       PST                 AST               Duration  Round-trip
DOY     Date      TX Window   TX Window           TX Window         hh:mm     time (sec)  SNR/Run 
---     ----      ---------   ---------           ---------         --------- -------     -------
038     Feb 07    0600-1005   2200-0205 Feb. 6-7  0200-0605 Feb 7    4:05      37          47
039-040 Feb 08-09 2145-0130   1345-1730 Feb. 8    1745-2130 Feb 8    3:45      27         140 

Arecibo Schedule 
042     Feb 11    1747-2001   0947-1201 Feb 11    1347-1601 Feb 11   2:14      26        2400 
043     Feb 12    1637-1918   0837-1118 Feb 12    1237-1518 Feb 12   2:41      31        1400 
044     Feb 13    1602-1838   0802-1038 Feb 13    1202-1438 Feb 13   2:36      37         710
045     Feb 14    1545-1803   0745-1003 Feb 14    1145-1403 Feb 14   2:18      44         390
046     Feb 15    1537-1733   0737-0933 Feb 15    1137-1333 Feb 15   1:56      52         210 
047     Feb 16    1535-1705   0735-0905 Feb 16    1135-1305 Feb 16   1:30      60         120  


Uncertainties

From Horizons, 2009 January 25: JPL solution 24, #obs = 142 (2003-2009)

 Date__(UT)__HR:MN     R.A._(J2000.0)_DEC.            delta POS_3sigma  DOP_S-sig  DOP_X-sig  RT_delay-sig
 2009-Feb-01 00:00 *m  116.30990  23.67896 0.089558777260380  1.16767802   0.49       1.74      0.001366
 2009-Feb-02 00:00 *m  114.80610  24.74609 0.080763808884575  1.35809286   0.50       1.78      0.001378
 2009-Feb-03 00:00 *m  112.92152  26.04499 0.072096687335434  1.60474234   0.51       1.83      0.001389
 2009-Feb-04 00:00 *m  110.48973  27.65248 0.063586689392386  1.93572973   0.53       1.88      0.001399
 2009-Feb-05 00:00 *m  107.23566  29.67621 0.055283589324997  2.40145107   0.54       1.94      0.001405
 2009-Feb-06 00:00 *m  102.67859  32.26008 0.047274200796850  3.09672499   0.56       2.01      0.001401
 2009-Feb-07 00:00 *m   95.92945  35.55970 0.039715324233611  4.20302806   0.58       2.08      0.001377
 2009-Feb-08 00:00 *m   85.29152  39.57221 0.032899637889872  6.04140079   0.60       2.16      0.001310
 2009-Feb-09 00:00 *    67.86984  43.43143 0.027372411452809  8.97114622   0.62       2.23      0.001151
 2009-Feb-10 00:00 *    41.87137  43.93376 0.024030536577349 12.5092997    0.63       2.27      0.000849

- - - - - - - - - - - - - - - - - - - - 

From Jon Giorgini, 2009 February 2:

With 238 optical measurements (2003-Aug-23 to 2009-Feb-1),
2006 AS2 soln. #32 was computed (now in Horizons). Formal 
3-sigma X-band uncertainties are shown below.

 Date__(UT)__HR:MN   POS_3sigma  DOP_X-sig  RT_delay-sig
 2009-Feb-06 00:00   2.04827140       1.98      0.001364
 2009-Feb-07 00:00   3.08733054       2.05      0.001338
 2009-Feb-08 00:00   4.89402094       2.11      0.001266
 2009-Feb-09 00:00   7.83629971       2.15      0.001097
 2009-Feb-10 00:00   11.4209206       2.12      0.000770


Setups


PLANS FOR THE FEBRUARY 7 TRACK:

Due to the 4.5 h rotation period and an educated guess for the diameter, 
we are expecting a bandwidth in the realm of 10 Hz, so we will start with the following setup,
which will resolve the echo in Doppler frequency and allow us to see echoes quickly:

TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           2                           
Dwell                    10 seconds                      
Bandwidth:               4000 Hz  
Sampling interval:       2500 x 0.1 usec 
VME FFT for PSD files:   4096 for 0.98-Hz resolution   

Then we will do 10 usec and 11 usec ranging with the standard setups below.
We hope to finish with 1/8 usec imaging.



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/data0/2006AS2/raw/

2006 AS2 POINTING:

   OSOD and predicts are on aardvark:

/export/data3/osod/ops/2006as2/PRDX.OUT.s34
                              /PUNCH.OUT.s34
                              /EPH.OUT.s34

POINTING  
                                                   TX Offsets    
Date (UTC)   DOY  hhmmss    RA       Dec   Macro  LHA      Dec    RTT    OSOD

2009 02 07   038  050000  94.2119 36.3656   A                     38.1    32
2009 02 07   038  060000  93.8092 36.5256   A                     37.8
2009 02 07   038  070000  93.3999 36.6846   A                     37.5
2009 02 07   038  080000  92.9850 36.8428   A      4.3     1.6    37.3
2009 02 07   038  090000  92.5655 37.0004   A                     37.0
2009 02 07   038  100000  92.1420 37.1579   A                     36.7
2009 02 07   038  110000  91.7148 37.3159   A                     36.4

2009 02 08   039  210000  70.7246 43.0236  A                      27.9    34
2009 02 08   039  220000  69.8535 43.1731  A       6.8     1.1    27.7
2009 02 08   039  230000  68.9584 43.3172  AB                     27.5
2009 02 09   040  000000  68.0399 43.4545   B      7.0     1.1    27.3
2009 02 09   040  010000  67.0991 43.5839   BC                    27.1 
2009 02 09   040  020000  66.1375 43.7042    C     7.3     0.8    26.9
2009 02 09   040  030000  65.1572 43.8144    C                    26.8

Transmit offsets are given in millidegrees.  


PRDX.OUT.s32 TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL 2009 FEB 07 05:00 38.1220169079 700363.725 1.3545 36.3656 94.212 88.555 2009 FEB 07 05:10 38.0729736296 699004.562 3.9280 36.3924 94.145 86.675 2009 FEB 07 05:20 38.0240255850 697646.359 6.5017 36.4191 94.078 84.643 2009 FEB 07 05:30 37.9751726682 696290.722 9.0755 36.4458 94.011 82.584 2009 FEB 07 05:40 37.9264146434 694939.245 11.6496 36.4724 93.944 80.517 2009 FEB 07 05:50 37.8777511460 693593.510 14.2239 36.4990 93.877 78.448 2009 FEB 07 06:00 37.8291817272 692255.083 16.7983 36.5256 93.809 76.379 2009 FEB 07 06:10 37.7807058295 690925.510 19.3729 36.5522 93.741 74.311 2009 FEB 07 06:20 37.7323227699 689606.315 21.9478 36.5787 93.673 72.246 2009 FEB 07 06:30 37.6840317685 688298.996 24.5227 36.6052 93.605 70.183 2009 FEB 07 06:40 37.6358319411 687005.022 27.0979 36.6317 93.537 68.125 2009 FEB 07 06:50 37.5877223021 685725.831 29.6732 36.6582 93.469 66.071 2009 FEB 07 07:00 37.5397017747 684462.825 32.2487 36.6846 93.400 64.021 2009 FEB 07 07:10 37.4917691588 683217.370 34.8243 36.7110 93.331 61.977 2009 FEB 07 07:20 37.4439231955 681990.790 37.4001 36.7374 93.262 59.938 2009 FEB 07 07:30 37.3961624990 680784.368 39.9760 36.7638 93.193 57.906 2009 FEB 07 07:40 37.3484856306 679599.339 42.5521 36.7901 93.124 55.881 2009 FEB 07 07:50 37.3008910312 678436.891 45.1283 36.8165 93.055 53.862 2009 FEB 07 08:00 37.2533770960 677298.162 47.7046 36.8428 92.985 51.852 2009 FEB 07 08:10 37.2059421153 676184.236 50.2811 36.8691 92.915 49.850 2009 FEB 07 08:20 37.1585843054 675096.142 52.8577 36.8953 92.846 47.857 2009 FEB 07 08:30 37.1113018395 674034.852 55.4344 36.9216 92.776 45.874 2009 FEB 07 08:40 37.0640927887 673001.279 58.0112 36.9479 92.706 43.901 2009 FEB 07 08:50 37.0169551892 671996.273 60.5881 36.9741 92.636 41.938 2009 FEB 07 09:00 36.9698870198 671020.624 63.1652 37.0004 92.566 39.987 2009 FEB 07 09:10 36.9228861793 670075.056 65.7424 37.0266 92.495 38.049 2009 FEB 07 09:20 36.8759505361 669160.227 68.3196 37.0529 92.425 36.123 2009 FEB 07 09:30 36.8290779325 668276.728 70.8970 37.0791 92.354 34.211 2009 FEB 07 09:40 36.7822661362 667425.082 73.4745 37.1054 92.284 32.313 2009 FEB 07 09:50 36.7355129074 666605.741 76.0521 37.1317 92.213 30.431 2009 FEB 07 10:00 36.6888159682 665819.088 78.6298 37.1579 92.142 28.565 2009 FEB 07 10:10 36.6421730162 665065.434 81.2076 37.1842 92.071 26.716 2009 FEB 07 10:20 36.5955817210 664345.019 83.7855 37.2105 92.000 24.885 2009 FEB 07 10:30 36.5490397468 663658.010 86.3635 37.2368 91.929 23.073 2009 FEB 07 10:40 36.5025447662 663004.502 88.9416 37.2631 91.858 21.281 2009 FEB 07 10:50 36.4560944035 662384.515 91.5198 37.2895 91.786 19.511 2009 FEB 07 11:00 36.4096863374 661797.999 94.0981 37.3159 91.715 17.763

2006 AS2 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 300-233 | FAX: (818) 354-9476 Jet Propulsion Laboratory | email: lance.benner@jpl.nasa.gov California Institute of Technology | Plan: To live long and prosper Pasadena, CA 91109-8099 http://echo.jpl.nasa.gov/asteroids/2006AS2/2006AS2_planning.html

Asteroid Radar Astronomy