Radar observations

Radar astronomy is one of the most effective methods of Earth-based remote sensing of asteroids, comets and planets of the solar system. The size, shape, spin period, high spatial resolution radar maps, surface and subsurface physical properties can be obtained using radar observations. Such observations suggest a transmitting and receiving antenna systems, a highly sensitive equipment for detecting echo signals and a software for observations scheduling and data processing. The Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS) regularly participates in international radar observations of Near-Earth Objects (NEOs) ^[1,2] and the Moon. Usually, the sources of radio signals are the 70-meter antenna of the Goldstone Deep Space Communications Complex (USA) and, until 2021, the 305-meter radio telescope located at the Arecibo Observatory (Puerto Rico), equipped with powerful transmitters. Detection of signals reflected from asteroids is performed with 32-meter or 13.2-meter radio telescopes of the Russian VLBI Network Quasar. The first radar observations in IAA RAS were carried out in July 2015 in collaboration with the Jet Propulsion Laboratory of the California Institute of Technology and the Goldstone Observatory. The object of study was the potentially hazardous asteroid 2011 UW158 during its close approach to the Earth.

Observations of NEOs

Observation Date	Object	Notes
2021 Dec 04-21	2003 SD220	Asteroid
2021 Dec 04-10	4660 Nereus	Asteroid
2021 May 03	2021 AF8	Asteroid
2020 Nov 30	2020 SO	Artificial Object
2020 Apr 19-22	1998 OR2	Asteroid
2018 Dec 17-22	2003 SD220	Asteroid
2018 Mar 05	2017 VR12	Asteroid
2017 Sep 04	3122 Florence	Triple Asteroid
2017 Apr 18-20	2003 BD44	Asteroid
2017 Apr 18-20	2014 JO25	Asteroid
2016 Oct 31	2003 YT1	Binary Asteroid
2016 Oct 29	2003 TL4	Asteroid
2015 Jul 18-19	2011 UW158	Asteroid

Observations of the Moon

Observation Date	Region	Notes
2021 Sep 07	Tycho	Crater
2021 Sep 07	Mare Serenitatis	Lunar mare
2021 Sep 07	Rima Hadley	Rille, Apollo 15 landing region
2021 Sep 01	Archimedes	Crater
2020 Oct 26-29	Archimedes	Crater
2020 Aug 13	Mare Imbrium	Lunar mare
2019 Apr 26	Mare Imbrium	Lunar mare, Chang'e 3 landing region

Observations of Planets

Observation Date	Planet
2022 Jan 22	Venus

Potential radar targets in 2022-23

Close-Approach Date	Object	H	D, m	P, h	R, au	R, LD
2022 Jan 18	1994 PC1	16.6	1052 (±303)	2.6	0.01325	5.15
2022 Mar 04	2001 CB21	18.4	560-1300	3.3	0.03283	12.78
2022 Apr 28	2008 AG33	19.4	350-780	-	0.02167	8.43
2022 May 27	1989 JA	17.5	1800	12.0	0.02690	10.47
2022 Nov 23	2005 LW3	21.6	130-280	-	0.00762	2.97
2022 Dec 27	2010 XC15	21.4	140-310	-	0.00516	2.01
2023 Feb 03	2011 AG5	21.9	110-250	-	0.01215	4.73
2023 Feb 16	2005 YY128	18.2	600-1300	-	0.03073	11.96
2023 Apr 13	2012 KY3	18.5	540-1200	-	0.03198	12.44
2023 Apr 26	2006 HV5	19.8	307 (±76)	-	0.01618	6.30
2023 Jun 12	1994 XD	19.1	400-900	2.7	0.02114	8.23
2023 Jun 15	2020 DB5	19.3	370-820	-	0.02880	11.21
2023 Jul 12	2018 UY	20.6	200-450	-	0.01904	7.41
2023 Oct 15	2011 GA	20.8	180-410	-	0.01744	6.79
2023 Oct 17	1998 HH49	21.3	150-330	-	0.00784	3.05
2023 Nov 02	2003 UC20	18.3	1876 (±37)	29.6	0.03511	13.66
2023 Dec 06	2001 QQ142	18.4	550-1200	-	0.03694	14.38

Radar detectability of near-Earth objects (NEO) for the RT-32 radio telescopes at 8560 MHz (3.5 cm). The dashed lines show the distance at which echoes from the NEOs with a given diameter can be detected at signal-to-noise ratio of 5. Calculations assume a signal transmitted by a 450 kW radar with a gain of 74 dB and reflected from a NEO with a rotation period of 0.5 h, 2.1 h, and 20.0 h and a radar albedo of 0.1 for the corresponding round-trip signal propagation time. The filled circles correspond to the NEOs detected on the RT-32, and the empty ones represent potential radar targets in 2022-23.

Publications

Remarks

This website section is maintained by Dr. Yuri Bondarenko and Dr. Dmitrii Marshalov.
This work was supported by the Russian Scientific Foundation grant No. 16-12-00071.