(7341) 1991 VK Goldstone Radar Observations Planning


Background


(7341) 1991 VK was discovered by Eleanor F. Helin and Kenneth J. Lawrence on November 1, 1991 from Palomar Observatory.
1991 VK is a PHA that we previously observed on two occasions with radar.  The first  was in January 1997 with Goldstone 
(CW and ranging, Ostro et al., 1998) and the second was in January of 2007 with Arecibo. This object has a 4.2-h 
rotation period (Pravec et al., 1998) and is ~1.4 km in diameter. To date, the best resolution achieved by radar 
was 1 usec (150 m). 

1991 VK approaches Earth at 25 lunar distances (LD) on Jan. 25, 2012, and we will observe it at Goldstone in the week 
prior to the closest approach.  1991 VK will be a relatively weak target at Goldstone, although we expect to obtain 
some 1 usec (150 m) images. This object will also be observed at Arecibo on Jan. 4-6, where we hope to image it with 
0.2 usec (30 m) resolution.  All of the Goldstone observations occur after 1991 VK moves too far south
for Arecibo to track.

1991 VK becomes a day-time object in early January, and it becomes observable again with optical telescopes 
in the southern hemisphere in the second part of February.

Orbital and Physical Characteristics  
 orbit type               Apollo
 semimajor axis           1.842  AU     
 eccentricity             0.507 
 inclination              5.422 deg       
 perihelion distance      0.909 AU     
 aphelion distance        2.776 AU     
 absolute magnitude (H)   16.7
 diameter                 1.4 km    (Arecibo radar images) 
 rotation period          4.2 h     (Pravec et al., 1998)
 pole direction           unknown 
 lightcurve amplitude     0.28-0.70 (Pravec et al., 1998)
 spectral class           Sq, Sr    (Binzel et al., 2002; Lazzarin et al., 2004)

Last update: 2012 Jan 21

First IAU circular

                                                  Circular No. 5392
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


1991 VK
     E. Helin and K. Lawrence (and the latter should also have been
credited with the discovery of 1991 VE on IAUC 5385) have discovered
another fast-moving asteroidal object with the 0.46-m Palomar
Schmidt, with assistance also from P. Rose:

     1991 UT             R.A. (1950) Decl.       Mag.
     Nov.  1.16337   23 45 14.30   +25 09 34.2   15.5
           1.19132   23 45 09.47   +25 09 28.6
           2.19063   23 42 28.72   +25 05 28.6
           4.21823   23 37 02.41   +24 55 56.0

     Preliminary orbital elements from the above observations by
B. G. Marsden, Harvard-Smithsonian Center for Astrophysics:

     T = 1992 Jan.  7.780 ET          Peri. = 173.254
     e = 0.50349                      Node  = 294.423   1950.0
     q = 0.91076 AU                   Incl. =   5.390
       a =  1.83431 AU     n = 0.396731     P =   2.48 years

     1991 ET      R.A. (1950) Decl.     Delta      r       V
     Nov. 20    22 56.88    +22 51.5    0.206    1.092    14.8
          25    22 44.92    +21 58.6
          30    22 32.69    +20 58.8    0.173    1.032    14.7
     Dec.  5    22 19.40    +19 48.3
          10    22 03.75    +18 19.3    0.138    0.981    14.7
          15    21 43.68    +16 15.9
          20    21 16.12    +13 08.3    0.102    0.942    15.2
          25    20 37.07    + 8 08.8
          30    19 43.57    + 0 31.3    0.076    0.918    18.3


1991 November 21               (5392)             Daniel W. E. Green

SNR Calculation

Target Name:   (7341) 1991 VK

D =         1.4 km  
Period =    4.2 h
OC albedo = 0.1
                                               #                 max
 start date    window       RA, dec   dist    runs        SNR   SNR/run
-----------------------------------------------------------------------
2012 Jan 10  18:25-02:41   331,  -4  0.104     156         41         4
2012 Jan 11  18:21-02:28   330,  -5  0.100     159         47         4
2012 Jan 12  18:18-02:14   329,  -6  0.096     163         55         5
2012 Jan 13  18:14-01:59   328,  -8  0.092     167         64         6
2012 Jan 14  18:11-01:43   326, -10  0.088     170         73         6
2012 Jan 15  18:08-01:25   325, -11  0.085     172         84         7
2012 Jan 16  18:05-01:05   323, -13  0.081     173         96         8
2012 Jan 17  18:03-00:44   321, -16  0.078     174        110         9
2012 Jan 18  18:01-00:19   319, -18  0.075     172        120        10
2012 Jan 19  18:01-23:52   316, -21  0.073     169        130        11
2012 Jan 20  18:01-23:22   313, -23  0.071     164        140        12
2012 Jan 21  18:04-22:47   310, -26  0.069     155        140        13
2012 Jan 22  18:09-22:06   307, -29  0.067     144        140        13
2012 Jan 23  18:22-21:17   303, -31  0.066     128        130        13
2012 Jan 24  18:56-20:02   299, -34  0.065     107        120        12
 
Goldstone SNRs assume Ptx = 450 kW 

Track Assignments


Goldstone tracks:

        UT          UT          PST                    Duration    Round-trip     
DOY     Date        TX Window   TX Window                hh:mm     time (sec)     SNR/Run 
---     ----        ---------   ---------              ---------    ---------     -------
015     Jan 15/16   2045-0105   1245-1705 Jan 15         04:20         84            7
017     Jan 17      2100-2330   1300-1530 Jan 17         02:30         78            9
020     Jan 20      2050-2320   1250-1520 Jan 20         03:00         70           12
022     Jan 22      1815-2205   1015-1405 Jan 22         03:50         67           13  Cancelled. DSS-14 code RED.

TXON is listed at the earliest time we can start to transmit, even if that occurs before 
the end of precal.


Scheduled Arecibo tracks:
        UT          UT          AST                PST                 Duration    Round-trip     
DOY     Date        TX Window   TX Window          TX Window           hh:mm      time (sec)     SNR/Run 
---     ----        ---------   ---------          ---------           ---------   ----------    ---------
004     Jan 04      1908-2041   1508-1641 Jan 04   1108-1241  Jan 04   01:33        131             43
005     Jan 05      1906-2030   1506-1630 Jan 05   1106-1230  Jan 05   01:24        126             46
006     Jan 06      1906-2019   1506-1619 Jan 06   1106-1219  Jan 06   01:13        122             48


Uncertainties

From Jon Giorgini, Jan 11 2012, Solution #166, #obs 892 (1991-2012), radar at 3 apparations

 Date__(UT)__HR:MN  POS_3sigma   DOP_X_3sig  RT_delay_3sig
 2012-Jan-15 00:00       0.396         0.47       0.000030
 2012-Jan-16 00:00       0.414         0.52       0.000035
 2012-Jan-17 00:00       0.431         0.57       0.000040
 2012-Jan-18 00:00       0.448         0.62       0.000045
 2012-Jan-19 00:00       0.464         0.67       0.000052
 2012-Jan-20 00:00       0.478         0.71       0.000058
 2012-Jan-21 00:00       0.490         0.74       0.000066
 2012-Jan-22 00:00       0.498         0.76       0.000073
 2012-Jan-23 00:00       0.503         0.76       0.000081

From JPL Horizons, Dec 02 2011, Solution #155, #obs 876 (1991-2011)

*******************************************************************************
 Date__(UT)__HR:MN     POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig

 2012-Jan-05 00:00 *m       0.556        0.14        0.51       0.000278
 2012-Jan-06 00:00 *m       0.586        0.16        0.58       0.000274
 2012-Jan-07 00:00 *m       0.619        0.18        0.65       0.000268
 2012-Jan-08 00:00 *m       0.655        0.20        0.74       0.000262
 2012-Jan-09 00:00 *        0.694        0.23        0.83       0.000256
 2012-Jan-10 00:00 *        0.737        0.26        0.94       0.000248
 2012-Jan-11 00:00 *        0.782        0.29        1.06       0.000239
 2012-Jan-12 00:00 *        0.831        0.33        1.19       0.000229
 2012-Jan-13 00:00 *        0.884        0.37        1.34       0.000218
 2012-Jan-14 00:00 *        0.941        0.41        1.50       0.000206
 2012-Jan-15 00:00 *        1.000        0.46        1.67       0.000193
 2012-Jan-16 00:00 *        1.063        0.51        1.86       0.000178
 2012-Jan-17 00:00 *        1.127        0.57        2.07       0.000161
 2012-Jan-18 00:00 *        1.193        0.63        2.28       0.000144
 2012-Jan-19 00:00 *        1.257        0.69        2.49       0.000126
 2012-Jan-20 00:00 *        1.318        0.74        2.69       0.000108
 2012-Jan-21 00:00 *        1.373        0.79        2.88       0.000092
 2012-Jan-22 00:00 *        1.420        0.84        3.04       0.000082
 2012-Jan-23 00:00 *m       1.455        0.87        3.15       0.000082
 2012-Jan-24 00:00 *m       1.476        0.88        3.21       0.000092
 2012-Jan-25 00:00 *m       1.482        0.88        3.20       0.000110

******************************************************************************************
Apparent Magnitudes and Solar Elongations:

 Date__(UT)__HR:MN     R.A._(J2000.0)_DEC.  APmag            delta    S-O-T /r
 2011-Dec-12 00:00 *   339.24076  10.24316  16.35 0.23316948422827    85.6370 /T
 2011-Dec-13 00:00 *   339.20620  10.08042  16.35 0.22949955473375    84.5696 /T
 2011-Dec-14 00:00 *   339.17131   9.91265  16.35 0.22576193824278    83.4984 /T
 2011-Dec-15 00:00 *   339.13509   9.73903  16.35 0.22195755772171    82.4219 /T
 2011-Dec-16 00:00 *   339.09650   9.55869  16.35 0.21808753138107    81.3388 /T
 2011-Dec-17 00:00 *   339.05446   9.37070  16.35 0.21415315785983    80.2478 /T
 2011-Dec-18 00:00 *   339.00783   9.17404  16.36 0.21015590306365    79.1473 /T
 2011-Dec-19 00:00 *   338.95540   8.96762  16.36 0.20609738987222    78.0359 /T
 2011-Dec-20 00:00 *   338.89590   8.75027  16.36 0.20197939262315    76.9116 /T
 2011-Dec-21 00:00 *   338.82798   8.52070  16.37 0.19780383929294    75.7728 /T
 2011-Dec-22 00:00 *   338.75015   8.27749  16.38 0.19357282497982    74.6175 /T
 2011-Dec-23 00:00 *   338.66082   8.01912  16.38 0.18928863964002    73.4435 /T
 2011-Dec-24 00:00 *   338.55823   7.74387  16.39 0.18495381032162    72.2483 /T
 2011-Dec-25 00:00 *m  338.44045   7.44986  16.41 0.18057115391364    71.0295 /T
 2011-Dec-26 00:00 *m  338.30539   7.13500  16.42 0.17614383280285    69.7840 /T
 2011-Dec-27 00:00 *m  338.15074   6.79698  16.43 0.17167540523357    68.5088 /T
 2011-Dec-28 00:00 *m  337.97397   6.43324  16.45 0.16716986524926    67.2003 /T
 2011-Dec-29 00:00 *m  337.77234   6.04095  16.48 0.16263167203619    65.8546 /T
 2011-Dec-30 00:00 *m  337.54285   5.61696  16.50 0.15806577259278    64.4675 /T
 2011-Dec-31 00:00 *m  337.28221   5.15781  16.54 0.15347762340135    63.0344 /T
 2012-Jan-01 00:00 *m  336.98684   4.65966  16.57 0.14887321640607    61.5502 /T
 2012-Jan-02 00:00 *m  336.65280   4.11824  16.62 0.14425911319275    60.0092 /T
 2012-Jan-03 00:00 *m  336.27576   3.52884  16.67 0.13964248977278    58.4053 /T
 2012-Jan-04 00:00 *m  335.85094   2.88626  16.73 0.13503119321760    56.7316 /T
 2012-Jan-05 00:00 *m  335.37306   2.18472  16.80 0.13043381062058    54.9807 /T
 2012-Jan-06 00:00 *m  334.83625   1.41786   n.a. 0.12585975032154    53.1444 /T
 2012-Jan-07 00:00 *m  334.23400   0.57865   n.a. 0.12131933493512    51.2137 /T
 2012-Jan-08 00:00 *m  333.55907  -0.34058   n.a. 0.11682390544345    49.1789 /T
 2012-Jan-09 00:00 *   332.80339  -1.34821   n.a. 0.11238593551077    47.0294 /T
 2012-Jan-10 00:00 *   331.95793  -2.45330   n.a. 0.10801915527812    44.7539 /T
 2012-Jan-11 00:00 *   331.01263  -3.66549   n.a. 0.10373868397912    42.3405 /T
 2012-Jan-12 00:00 *   329.95622  -4.99493   n.a. 0.09956117019737    39.7771 /T
 2012-Jan-13 00:00 *   328.77609  -6.45203   n.a. 0.09550493648403    37.0515 /T
 2012-Jan-14 00:00 *   327.45815  -8.04706   n.a. 0.09159012034438    34.1527 /T
 2012-Jan-15 00:00 *   325.98666  -9.78967   n.a. 0.08783879566416    31.0720 /T
 2012-Jan-16 00:00 *   324.34413 -11.68809   n.a. 0.08427504757890    27.8058 /T
 2012-Jan-17 00:00 *   322.51125 -13.74803   n.a. 0.08092496047515    24.3598 /T
 2012-Jan-18 00:00 *   320.46691 -15.97135   n.a. 0.07781646492815    20.7592 /T
 2012-Jan-19 00:00 *   318.18850 -18.35430   n.a. 0.07497897784426    17.0691 /T
 2012-Jan-20 00:00 *   315.65235 -20.88567   n.a. 0.07244276593750    13.4508 /T
 2012-Jan-21 00:00 *   312.83469 -23.54482   n.a. 0.07023797376432    10.3150 /T
 2012-Jan-22 00:00 *   309.71321 -26.30021   n.a. 0.06839329337552     8.6366 /T
 2012-Jan-23 00:00 *m  306.26924 -29.10862   n.a. 0.06693431997458     9.5806 /T
 2012-Jan-24 00:00 *m  302.49085 -31.91603   n.a. 0.06588173242267    12.7705 /L
 2012-Jan-25 00:00 *m  298.37664 -34.66011   n.a. 0.06524953620529    17.0792 /L

Setups



We are expecting a bandwidth of about 30 Hz, and the Doppler uncertainties are
small, so we will start with a standard CW setup to verify that we have echoes:

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:    1024 for 3.9 Hz resolution 

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 Hz   
resolution       12.3 Hz
TXOFF          +150 Hz -> echo will be centered at +12 bins or in bin 32 + 12 = 44
---------------------------------------------------------------------------
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        717  Hz   
resolution       11.2  Hz
TXOFF          +150 Hz --> echo will be centered at +13 bins or in bin 32 + 13 =45 
-------------------------------------------------------------------------
1-usec coarse imaging
----------------------------
baud              1 usec
code              127    (so that VME can display it)
ncoh              12
bandwidth         656 Hz
FFT               128
resolution        5.1 Hz
TXoff             +100 Hz  (echo in bin 64+20 =84)

_____________________________________________________________________
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/data0/1991VK/raw/

1991 VK POINTING:

  OSOD and predicts are on aardvark:

/export/apps0/temp_data/data3/osod/ops/a7341/PRDX.OUT.14f-14-14.s170 
                              /PUNCH.OUT.14f-14-14.s170
                              /EPH.OUT.s170


POINTING  
                                                          TX Offsets    
Date (UTC)   DOY  hhmmss    RA        Dec         Macro   LHA     Dec    RTT    OSOD
2012 01 22   022  180000    307.3899 -28.3674       A                    67.1     
2012 01 22   022  190000    307.2350 -28.4865       A                    67.1     
2012 01 22   022  200000    307.0787 -28.6047       A     2.90  -2.20    67.0   s170
2012 01 22   022  210000    306.9217 -28.7220       A                    66.9      
2012 01 22   022  220000    306.7646 -28.8382       A                    66.9    

Transmit offsets are given in millidegrees.  


PRDX.OUT.14f-14-14.s170 TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL 2012 JAN 22 18:00 67.1185126051 145046.268 327.2214 -28.3674 307.390 19.113 2012 JAN 22 18:10 67.1083808925 144042.011 329.7539 -28.3873 307.364 20.103 2012 JAN 22 18:20 67.0983202368 143019.026 332.2865 -28.4072 307.338 21.024 2012 JAN 22 18:30 67.0883318994 141978.776 334.8192 -28.4270 307.313 21.875 2012 JAN 22 18:40 67.0784170381 140922.761 337.3519 -28.4469 307.287 22.651 2012 JAN 22 18:50 67.0685767042 139852.510 339.8846 -28.4667 307.261 23.351 2012 JAN 22 19:00 67.0588118416 138769.578 342.4174 -28.4865 307.235 23.972 2012 JAN 22 19:10 67.0491232841 137675.546 344.9502 -28.5063 307.209 24.511 2012 JAN 22 19:20 67.0395117534 136572.015 347.4830 -28.5260 307.183 24.968 2012 JAN 22 19:30 67.0299778580 135460.605 350.0159 -28.5457 307.157 25.339 2012 JAN 22 19:40 67.0205220943 134342.950 352.5488 -28.5654 307.131 25.624 2012 JAN 22 19:50 67.0111448411 133220.695 355.0818 -28.5851 307.105 25.821 2012 JAN 22 20:00 67.0018463642 132095.495 357.6147 -28.6047 307.079 25.930 2012 JAN 22 20:10 66.9926268107 130969.008 0.1477 -28.6243 307.053 25.950 2012 JAN 22 20:20 66.9834862137 129842.896 2.6807 -28.6439 307.026 25.880 2012 JAN 22 20:30 66.9744244876 128718.817 5.2137 -28.6635 307.000 25.722 2012 JAN 22 20:40 66.9654414331 127598.427 7.7467 -28.6830 306.974 25.476 2012 JAN 22 20:50 66.9565367327 126483.372 10.2797 -28.7025 306.948 25.143 2012 JAN 22 21:00 66.9477099562 125375.287 12.8128 -28.7220 306.922 24.725 2012 JAN 22 21:10 66.9389605568 124275.794 15.3458 -28.7414 306.896 24.222 2012 JAN 22 21:20 66.9302878768 123186.497 17.8788 -28.7608 306.869 23.637 2012 JAN 22 21:30 66.9216911464 122108.977 20.4119 -28.7802 306.843 22.972 2012 JAN 22 21:40 66.9131694842 121044.795 22.9449 -28.7996 306.817 22.230 2012 JAN 22 21:50 66.9047219019 119995.482 25.4779 -28.8189 306.791 21.413 2012 JAN 22 22:00 66.8963473046 118962.541 28.0109 -28.8382 306.765 20.524 2012 JAN 22 22:10 66.8880444930 117947.441 30.5439 -28.8575 306.739 19.566 2012 JAN 22 22:20 66.8798121660 116951.616 33.0769 -28.8768 306.712 18.541

1991VK 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/1991VK/1991VK_planning.html

Asteroid Radar Astronomy
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