(433) Eros Goldstone Radar Observations Planning
Asteroid (433) Eros was discovered on August 13, 1898 by Carl Gustav Witt. With an effective diameter of ~17 km, Eros is the second (after 1036 Ganymed) largest asteroid in the near-Earth population. Eros was one of the earliest radar targets, observed in 1975 at Goldstone by Jurgens and Goldstein (1976) and at Arecibo by Campbell et al. (1976), and then again in 1988 at Arecibo (Magri et al., 2001). A radar-based ellipsoid model for Eros was estimated by Jurgens and Goldstein (1976). A more detailed radar-based convex-hull model was published by Ostro et al. (1990) and 3-D model was published by Mitchell et al. (1998). Eros was visited by NEAR spacecraft in 2000-2001, so its physical characteristics are exceptionally well known (Yeomans et al., 2000). It has a rotation period of 5.27 hours, with dimensions 34.4x11.2x11.2 km. Its bulk density is 2.67 g/cm^3 and it belongs to the S class. Due to its significant elongation, the echo bandwidths and appearance of delay-Doppler radar images during our tracks will change dramatically as the asteroid rotates. Eros makes its closest approach (within 0.179 AU) with respect to Earth in 27 years on January 31, 2012. We plan to observe it with Goldstone during the last week of January. The bandwidth at Goldstone will be ~200-600 Hz due to a significant elongation of Eros. This asteroid will be a moderately strong radar target. We hope to resolve the shape of Eros with 25 usec (3.75 km) coarse imaging setup.
Orbital and Physical Characteristics orbit type Amor semimajor axis 1.458 AU eccentricity 0.223 inclination 10.83 deg perihelion distance 1.133 AU aphelion distance 1.782 AU absolute magnitude (H) 11.16 dimensions 34.4x11.2x11.3 km (Yeomans et al., 2000, NEAR mission) diameter 16.84 km rotation period 5.27 h Asteroid Lightcurve DataBase (Rev. 2010-Mar-21) pole direction (eclipt. long=17.2, lat.=+11.3) (Miller et al., 2002) lightcurve amplitude 0.04-1.49 spectral class S Last update: 2012 Jan 29
Target Name: (433) Eros
D = 16.84 km
Period = 5.27 hr
OC albedo = 0.100
# max
start date window RA, dec dist runs SNR SNR/run
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2012 Jan 20 05:52-15:12 160, +7 0.186 97 200 23
2012 Jan 21 05:51-15:04 160, +6 0.185 97 210 23
2012 Jan 22 05:49-14:57 160, +5 0.184 96 210 24
2012 Jan 23 05:48-14:49 160, +3 0.183 96 210 24
2012 Jan 24 05:47-14:41 160, +2 0.182 95 220 25
2012 Jan 25 05:46-14:33 160, +1 0.181 95 220 25
2012 Jan 26 05:45-14:25 160, 0 0.180 94 220 25
2012 Jan 27 05:44-14:17 159, -1 0.180 93 220 26
2012 Jan 28 05:42-14:09 159, -2 0.179 92 220 26
2012 Jan 29 05:41-14:00 159, -3 0.179 91 220 26
2012 Jan 30 05:40-13:52 159, -4 0.179 90 220 26
2012 Jan 31 05:38-13:43 158, -5 0.179 89 220 26
2012 Feb 1 05:37-13:34 158, -6 0.179 88 210 26
2012 Feb 2 05:36-13:26 158, -7 0.179 87 210 25
2012 Feb 3 05:34-13:17 158, -8 0.179 85 210 25
2012 Feb 4 05:33-13:08 157, -9 0.180 84 200 25
Goldstone SNRs assume Ptx = 450 kW
The measured radar albedo of Eros is about 0.2, so the SNRs should be roughly double
the numbers shown above.
Goldstone tracks:
UT UT PST Duration Round-trip
DOY Date TX Window TX Window hh:mm time (sec) SNR/Run
--- ---- --------- --------- --------- --------- -------
026 Jan 26 0535-0955 2135-0155 Jan 25/26 04:20 180 25
027 Jan 27 0535-0955 2135-0155 Jan 26/27 04:20 179 26
028 Jan 28 0535-0950 2135-0150 Jan 27/28 04:15 179 26
030 Jan 30 0535-0940 2135-0140 Jan 29/30 04:05 178 26
TXON refers to the earliest time we can start to transmit, which may occur before the end of precal.
From Jon Giorgini, Jan 22 2012, Solution #396: using a subset of 4370 optical (1963-Jul-15 to 2012-Jan-19), 1 delay and 3 Doppler from Arecibo (1975, 1988) and DSS-14 (1975), and spacecraft tracking data from the NEAR mission, 433 Eros orbit solution #396 has formal 3-sigma X-band uncertainties as shown below. Date__(UT)__HR:MN POS_3sigma DOP_X_3sig RT_delay_3sig 2012-Jan-25 00:00 0.025 0.01 0.000013 2012-Jan-26 00:00 0.025 0.01 0.000013 2012-Jan-27 00:00 0.025 0.01 0.000012 2012-Jan-28 00:00 0.025 0.01 0.000012 2012-Jan-29 00:00 0.025 0.01 0.000012 2012-Jan-30 00:00 0.025 0.01 0.000012 2012-Jan-31 00:00 0.026 0.01 0.000012 From JPL Horizons, Nov 27 2011, Solution #386, #obs 4338 (1963-2011) ******************************************************************************* Date__(UT)__HR:MN POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2012-Jan-20 00:00 * 0.545 0.06 0.22 0.000324 2012-Jan-21 00:00 * 0.549 0.06 0.23 0.000324 2012-Jan-22 00:00 * 0.553 0.06 0.23 0.000323 2012-Jan-23 00:00 *m 0.556 0.07 0.24 0.000322 2012-Jan-24 00:00 *m 0.560 0.07 0.25 0.000320 2012-Jan-25 00:00 *m 0.563 0.07 0.27 0.000319 2012-Jan-26 00:00 *m 0.566 0.08 0.28 0.000317 2012-Jan-27 00:00 *m 0.569 0.08 0.30 0.000315 2012-Jan-28 00:00 *m 0.571 0.09 0.31 0.000312 2012-Jan-29 00:00 *m 0.574 0.09 0.33 0.000309 2012-Jan-30 00:00 *m 0.576 0.10 0.35 0.000307 2012-Jan-31 00:00 *m 0.577 0.10 0.37 0.000304 2012-Feb-01 00:00 *m 0.579 0.11 0.39 0.000300 2012-Feb-02 00:00 *m 0.580 0.11 0.41 0.000297 2012-Feb-03 00:00 *m 0.581 0.12 0.43 0.000293 2012-Feb-04 00:00 *m 0.581 0.12 0.45 0.000289 2012-Feb-05 00:00 *m 0.581 0.13 0.47 0.000285 ****************************************************************************************** Apparent Magnitudes and Solar Elongations: Date__(UT)__HR:MN R.A._(J2000.0)_DEC. APmag delta S-O-T /r 2012-Jan-20 00:00 * 160.17171 7.31238 8.76 0.18657986257210 140.1856 /L 2012-Jan-21 00:00 * 160.09929 6.21473 8.73 0.18527610427502 140.8256 /L 2012-Jan-22 00:00 * 160.00672 5.11099 8.70 0.18408610590037 141.4552 /L 2012-Jan-23 00:00 *m 159.89429 4.00274 8.68 0.18301165456355 142.0719 /L 2012-Jan-24 00:00 *m 159.76238 2.89162 8.66 0.18205431734724 142.6728 /L 2012-Jan-25 00:00 *m 159.61141 1.77939 8.64 0.18121541525112 143.2554 /L 2012-Jan-26 00:00 *m 159.44185 0.66783 8.62 0.18049600807213 143.8168 /L 2012-Jan-27 00:00 *m 159.25424 -0.44118 8.60 0.17989688890561 144.3544 /L 2012-Jan-28 00:00 *m 159.04916 -1.54575 8.59 0.17941858547184 144.8655 /L 2012-Jan-29 00:00 *m 158.82722 -2.64395 8.58 0.17906136522001 145.3475 /L 2012-Jan-30 00:00 *m 158.58908 -3.73384 8.57 0.17882524184324 145.7981 /L 2012-Jan-31 00:00 *m 158.33544 -4.81348 8.56 0.17870998190548 146.2151 /L 2012-Feb-01 00:00 *m 158.06703 -5.88094 8.55 0.17871511129772 146.5965 /L 2012-Feb-02 00:00 *m 157.78462 -6.93435 8.55 0.17883992202659 146.9408 /L 2012-Feb-03 00:00 *m 157.48903 -7.97187 8.55 0.17908348039848 147.2464 /L 2012-Feb-04 00:00 *m 157.18107 -8.99175 8.55 0.17944463805658 147.5126 /L 2012-Feb-05 00:00 *m 156.86163 -9.99229 8.55 0.17992204755706 147.7385 /L
CW setup:
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TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: 4
Dwell 30 seconds
Bandwidth: 16000 Hz
Sampling interval: 625 x 0.1 usec
VME FFT for PSD files: 512 for 31.3-Hz resolution
Possible ranging setups:
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15 x 64 25-usec single sample
baud 25 usec
code 15
FFT 128
ncoh 1
bandwidth 2667 Hz
resolution 21 Hz
TXOFF 300 Hz -> echo will be centered at bins or in bin 64+14 =78
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baud 11 usec
code 31
FFT 128
ncoh 1
bandwidth 2933 Hz
resolution 23 Hz
TXOFF 300 Hz -> echo will be centered at bins or in bin 64+13 =77
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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.
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Setup Baud RP 1-acc 1-acc
usec m usec band res acc band res
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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
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OSOD and predicts are on aardvark:
/export/apps0/temp_data/data3/osod/ops/a433/PRDX.OUT.14f-14-14.s396
/PUNCH.OUT.14f-14-14.s396
/EPH.OUT.14f-14-14.s396
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2012 01 30 030 060000 158.6927 -4.0718 A 178.4
2012 01 30 030 070000 158.6803 -4.1171 A 178.4
2012 01 30 030 080000 158.6674 -4.1623 A 0.60 -2.20 178.4 s396
2012 01 30 030 090000 158.6542 -4.2074 A 178.4
2012 01 30 030 100000 158.6407 -4.2525 A 178.4
Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.s396
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2012 JAN 30 06:00 178.3909020751 32511.647 303.3108 -4.0718 158.693 23.905
2012 JAN 30 06:10 178.3886445939 31896.119 305.8197 -4.0794 158.691 25.750
2012 JAN 30 06:20 178.3864314448 31246.822 308.3285 -4.0869 158.689 27.565
2012 JAN 30 06:30 178.3842649617 30564.842 310.8374 -4.0945 158.687 29.348
2012 JAN 30 06:40 178.3821473914 29851.327 313.3464 -4.1020 158.684 31.093
2012 JAN 30 06:50 178.3800809044 29107.486 315.8553 -4.1095 158.682 32.799
2012 JAN 30 07:00 178.3780675805 28334.586 318.3642 -4.1171 158.680 34.460
2012 JAN 30 07:10 178.3761094124 27533.951 320.8732 -4.1246 158.678 36.072
2012 JAN 30 07:20 178.3742082986 26706.957 323.3822 -4.1322 158.676 37.631
2012 JAN 30 07:30 178.3723660286 25855.030 325.8912 -4.1397 158.674 39.130
2012 JAN 30 07:40 178.3705843072 24979.646 328.4002 -4.1472 158.672 40.565
2012 JAN 30 07:50 178.3688647235 24082.324 330.9092 -4.1548 158.670 41.929
2012 JAN 30 08:00 178.3672087587 23164.626 333.4182 -4.1623 158.667 43.215
2012 JAN 30 08:10 178.3656177832 22228.152 335.9272 -4.1698 158.665 44.417
2012 JAN 30 08:20 178.3640930620 21274.541 338.4363 -4.1773 158.663 45.528
2012 JAN 30 08:30 178.3626357340 20305.462 340.9453 -4.1849 158.661 46.541
2012 JAN 30 08:40 178.3612468240 19322.614 343.4544 -4.1924 158.659 47.448
2012 JAN 30 08:50 178.3599272369 18327.724 345.9634 -4.1999 158.656 48.242
2012 JAN 30 09:00 178.3586777556 17322.540 348.4725 -4.2074 158.654 48.916
2012 JAN 30 09:10 178.3574990438 16308.833 350.9816 -4.2149 158.652 49.465
2012 JAN 30 09:20 178.3563916284 15288.385 353.4907 -4.2225 158.650 49.883
2012 JAN 30 09:30 178.3553559271 14262.997 355.9998 -4.2300 158.647 50.167
2012 JAN 30 09:40 178.3543922187 13234.476 358.5089 -4.2375 158.645 50.312
2012 JAN 30 09:50 178.3535006573 12204.634 1.0179 -4.2450 158.643 50.318
2012 JAN 30 10:00 178.3526812739 11175.289 3.5270 -4.2525 158.641 50.184
2012 JAN 30 10:10 178.3519339720 10148.255 6.0361 -4.2600 158.638 49.912
2012 JAN 30 10:20 178.3512585283 9125.344 8.5452 -4.2675 158.636 49.504
2012 JAN 30 10:30 178.3506545823 8108.357 11.0543 -4.2750 158.634 48.965
2012 JAN 30 10:40 178.3501216598 7099.086 13.5634 -4.2825 158.632 48.300
2012 JAN 30 10:50 178.3496591620 6099.308 16.0725 -4.2900 158.629 47.516
2012 JAN 30 11:00 178.3492663532 5110.780 18.5815 -4.2975 158.627 46.617
Eros GOLDSTONE MASTERLOG
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Receive TX
Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes
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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/433_Eros_2012/Eros_planning.html
Asteroid Radar Astronomy