Title (insert one line only)

LFVN annual observations: radar measurements of space debris and solar wind research 

Principal Investigator (including name, address, telephone, fax, email)

Igor Molotov, 
Keldysh Institute of Applied Mathematics, 
Miusskaya sq., 4., Moscow, 125047, Russia
Tel: 7(495) 1529594, Fax: 7(495) 1529594
Email: molotov@vimpel.ru, molotov@kiam1.rssi.ru

Coauthors 
Gino Tuccari (IRA-INAF)
Stelio Montebugnoli (IRA-INAF)
Maria Nechaeva (Radio Physical Research Institute, Russia)
Vladimir Agapov (Keldysh Institute of Applied Mathematics, Russia)
Igor Falkovich (Institute of Radio Astronomy, Ukraine)
Giuseppe Pupillo (ISAC-CNR)
Liu Xiang (Urumqi Astronomical Observatory)
Alexander Volvach (Crimean Astrophysical Observatory)
Gennadij Kharlamov (Special Research Bureau, Russia)
Pietro Bolli (IRA-INAF)
Ivar Shmeld (Institute of Astronomy, Latvia)

observer{Who will come for observations}   
Noto: G. Tuccari, P. Bolli
Medicina: S. Montebugnoli, G. Pupillo

 Is this a resubmission of a previous proposal? 
 Is this a continuation of a previous proposal? (11-06, 13-05, Radar VLBI, INTAS)
 Is this for a Ph.D. project? (Student's name)

 Amount of time 
 this  proposal
 	hours{60}                        
{for full completion: 60} {already allocated}
totalhours{}{}

Sidereal time intervals:  {September 3} {September 12} {number of intervals: 5}

Receivers (Medicina parabola)
	 secondary focus
       6.6 GHz
       6.0 GHz
       5.0 GHz

	primary focus
        22 GHz
        8.3 GHz
        2.3 GHz
        1.6 GHz
        1.4 GHz

Receivers (Noto parabola)
		secondary focus
  		 43 GHz
  		 22 GHz
   		 6.6 GHz
   		 6.0 GHz
   		 5.0 GHz
    		 1.6 GHz
  		 1.4 GHz

 		primary focus
		 32 GHz
 		 12 GHz
		 8.3 GHz
		 2.3 GHz

 VLBI frontends
	 secondary focus
	6.6 GHz
	6.0 GHz
	5.0 GHz
	primary focus
	 22 GHz
	 8.3 GHz
	 2.3 GHz
	 1.6 GHz
	 1.4 GHz

 Medicina digital backend
 Medicina autocorrelator
 Medicina digital spectrometer
 Medicina pulsar backend
 Medicina polarimeter
 Specify guest instrument with a keyword
 Noto digital backend
 Noto autocorrelator
 Specify guest instrument with a keyword    NRTV terminal
 Mark IV backend for VLBI
 Mark V backend for VLBI

abstract{Put here a short and comprehensive abstract. }
LFVN team of radio telescopes in Italy, Russia, Ukraine and China carries out the VLBI observations each year since 1997 for few scientific directions: development of VLBI radar method for investigation of the Solar system bodies; researching the interplanetary medium irregularities using VLBI radio raying of the solar wind and solar corona; and adjusting e-VLBI technique. The interesting results in all mentioned fields were obtained in series of earlier experiments (VLBR 02.1, 03.1, 04.2, 05.1, 06.1, 07.1, and 07.2). 
In 2008, it is planned to arrange single VLBR08.1 session in order to continue the investigations of small space debris fragments at Geostationary orbit area that will be discovered in current optical observing campaigns of the Inter-Agency Space Debris Coordination Committee. Optical observations are not enough in order to obtain the understanding of properties of the unique space objects with high area to mass ratio (up to 50 square m per kg and even more), but only single radar system with Evpatoria RT-70 transmitter and VLBI array of radio telescopes was able to detect their echoes. Also during this session the new data on interplanetary medium will be obtained by VLBI observations of the extragalactic radio sources on different elongation angles from the Sun. Noto RT-32, Medicina RT-32, EvpatoriaRT-70, Kalyazin RT-64 (or Bear Lakes RT-64), Urumqi RT-25, Simeiz RT-22 and Ventspils RT-32 would participate in this session using Mk-5, NRTV and Mk-2 recording terminals. The recorded data will be downloaded using Internet and analyzed in Noto, Medicina, N. Novgorod and Moscow, and then interpreted in the Keldysh Institute of Applied Mathematics and Agenzia Spaziale Italiana.

 Scientific justification 
(max. 2 pages of text plus 2 pages of Figs., Tables and Refs.)
	The project of the Low Frequency VLBI Network was started in 1996 in order to arrange the international VLBI cooperation with participation of former USSR radio telescopes, and the Istituto di Radioastronomia (IRA) participates in the project from start point [1]. Traditionally the LFVN goals are developments of new VLBI methods and techniques including the investigations of the Solar system bodies by VLBI radar (VLBR) technique and the studying of the solar wind plasma by the method of radio raying [2]. The learning of the near-real-time VLBI (NRTV) through Internet using dedicated NRTV terminals designed in the IRA was begun in 2004 [3].
	The VLBR combines the radar sounding of planets, asteroids, and space debris objects with Evpatoria RT-70 C-band transmitter and the VLBI receiving of the reflected echo-signals with LFVN in order to obtain the 3-D measurements: the radar has the resolution for range and radial velocity, and the VLBI provides the angle and angular rate. Such new scientific instruments is able to measure the variations of proper rotation of the Earth group planets; determine the trajectories of planets and asteroids at Radio Reference Frame, to obtain the data on the space debris object sizes and structure of surface [4]. Since 2001 the capacity of VLBR to investigate new space debris problem was studied, including the attempts to obtain the radar detection of the space debris at Geostationary orbit (GEO) [5], because of the problem of studying the real population of space debris objects in the GEO region is extremely important. On the one hand, geostationary orbit represents an unique area of the near space from the point of view of solving the various tasks (television and communication services, weather monitoring, data relay, etc.), and, on the other hand, it is a limited natural resource which requires preservation for future use. There is no natural mechanism of self-cleaning here, similar to the low Earth orbit (LEO) region (decay of space debris fragments in the Earth atmosphere). Most of the GEO objects will live eternally, moving along the orbit. The echoes about 150 space objects were detected and the procedure of measurements of the precise Doppler shift, fringe rates, rotation period of objects and orientation of rotation axis, the size of objects and its main constructions were adjusted [6]. 
	The first measurements of Doppler shift and rotation period for small fragment of space debris were obtained in VLBR06.1 experiment [7]. This is very topical goal due to ESA and Russian optical facilities fixed hundreds GE)-fragments of 10-50 cm size, and it is necessary to determine their orbits in order to evaluate dangerous for operational satellites, and to clarify their releasing  sources in order to preserve GEO for future usage [8]. Most important goal in this field is an investigation of very unusual objects with high area to mass ratio (AMR - up to 50 square m per kg and even more). They were discovered few years ago [9] and their physical and ballistic properties are not clear. The orbits of these small solar sails are dramatically changed under influence of solar radiation pressure and they are moving from GEO and crossing all kinds of orbits and even entering into the Earth atmosphere. The Inter-Agency Space Debris Coordination Committee (IADC) is already arranging second large international campaign directed on discovering and further continuous tracking  of fragments with high AMR, but i.e. color photometry observations of such objects can not provide enough information due to fast object rotation. Therefore it is necessary to involve other type of measurements, i.e. radar. And only single radar system with Evpatoria RT-70 transmitter and VLBI array of radio telescopes confirmed in the VLBR07.1&07.2 experiments that is able to detect their echoes [10]. During VLBR08.1 it is planned to arrange the VLBI radar investigations of the objects with high AMR discovered into IADC optical observing campaigns. The International scientific optical network [8] will improve the ephemerides of objects selected for VLBI radar observations before VLBR08.1 session. It is expected that rows of precise Doppler shift measurements, evaluations of rotation periods and rotation axis orientations for objects with high AMR will be obtained. 
	Other part of VLBR08.1 will be devoted to the investigation of solar wind plasma by the method of radio raying developed by LFVN team [11]. During the observations, VLBI complex receives the radio emission of an extragalactic source, located at different angular distances from the Sun (4-40 degrees). Radio emission passes through the turbulent plasma of solar wind and carries information about solar wind plasma. LFVN with various orientations and lengths of baseline projections allows to obtain information about spatial structure of solar wind plasma parameters. The series of experiments on VLBI radio probing of solar wind plasma was carried out at C, L and P bands during 1998-2005 [12] allowed to adjust the measuring procedure of the value of a solar wind velocity V and an index of spatial spectrum of electron density fluctuations p by a spectral analysis of correlated signals. Distribution of large-scale intensive irregularities of electron density is derived from the variations of spectrum’s width, and the properties of the weak small-scale irregularities may be understood from the spectrum ‘wings’ shapes [13]. It is planned to continue these experiments in 2008 . 
	Additional goals of two proposed sessions will be further development of the NRTV terminals and digital BBC designed in IRA, correlation processing centers in N. Novgorod and Moscow and tests of the Ventspils RT-32 at C-band. During 2007, new correlation processing center appeared in Moscow, in Keldysh Institute of Applied Mathematics, which confirmed the ability to process Mk-5 format data. The Mk-5 data of Medicina RT-32 from VLBR07.1&07.2 was downloaded through Internet, converted into NRTV format and partially processed (autocorrelation and cross-processing with the transmitting signal recording from  Evpatoria).  Also, in 2007, the C-band receiver and feed-horn were installed in Ventspils RT-32, and this radio telescope participated in VLBR07.2 with NRTV and Mk-2 recording terminals, but no result was obtained due to problem with Base Band Converter. During VLBR08.1 new Italian digital BBC will be used in Ventspils RT-32. 
Noto RT-32, Medicina RT-32, EvpatoriaRT-70, Kalyazin RT-64 (or Bear Lakes RT-64), Urumqi RT-25, Simeiz RT-22 and Ventspils RT-32 would participate in this session using Mk-5, NRTV and Mk-2 recording terminals. The recorded data will be downloaded using Internet and analyzed in Noto, Medicina, N. Novgorod (Radio Physical Research Institute) and Moscow (Keldysh Institute of Applied Mathgematics), and then interpreted in the Keldysh Institute of Applied Mathematics and Agenzia Spaziale Italiana.

References:
	
1. Molotov I. E., Likhachev S. F., Chuprikov A. A., Dementiev A., Lipatov B., Nechaeva M.,  Snegirev S., Dugin N., Ananthakrishnan S., Balasubramanian V., Benz A., Mantovani F.,  Liu X., Hong X., Kus A., Molotov E. P., Ignatov S. P., Poperechenko B. A., Gorshenkov Y. N., Konovalenko A. A. Low Frequency VLBI Project. The Universe at Low Radio Frequencies,  Proceedings of IAU Symposium 199, held 30 Nov - 4 Dec 1999, Pune, India. Edited by A. Pramesh  Rao, G. Swarup, and Gopal-Krishna, 2002., p.492-493.
	2. I. Molotov, A. Kovalenko, V. Samodurov, B. Lipatov, A. Dementiev, A. Antipenko, S. Snegirev, M. Nechaeva, V. Reznikova, V. Altunin, A. Benz, F. Mantovani, C. Stanghellini, G. Tuccari, A. Konovalenko, I. Falkovich, A. Gridin, S. Ananthakrishnan, V. Balasubramanian, M. Sankararaman, X. Hong, X. Huang, L. Shiguang, S. Dougherty, D. Del Rizzo, A. Fink, X. Liu, W. Na, J. Zhang, A. Kus, K. Borkowski, J. Quick, G. Nicolson, I. Shmeld, Y. Koyama, M. Sekido, Yu. Gorshenkov, B. Poperechenko, V. Saurin, G. Ozolins, D. Bezrukov, X. Zhang. International Low-Frequency Very-Long-Baseline Interferometry Network Project Milestones. Astronomical and Astrophysical Transactions, Vol. 22, Nos. 4-5, August-October 2003, pp. 743-752.
	3. Tuccari G., Molotov I., Nechaeva M., Volvach A., Xiang L., Hong X., Buttaccio S., Gorshenkov Y. & Nicotra G. E-LFVN - An Internet Based VLBI Network Proceedings of 7th European VLBI Network Symposium on VLBI Scientific Research & Technology Toledo Spain. October 12-15, 2004, Edited by Rafael Bachiller, Francisco Colomer, Jean-Fransois Desmurs, Pablo de Vicente. Observatorio Astronomico Nacional, pp. 331-332. 
	4. Molotov, I. E.; Volvach, A. E.; Konovalenko, A. A.; Falkovich, I. S.; Litvinenko, L. N.; Negoda, A. A.; Fedorov, O. P.; Lipatov, B. N.; Gorshenko, Yu. N.; Agapov, V. M.; Tuccari, G.; Liu, X. International experiments on development of VLBI radar method for research of near-Earth bodies.  Kosmichna Nauka i Tekhnologiya, Vol. 10, No. 2/3, p. 87 - 92 (2004) (In Russian).
	5. I. Molotov, A. Konovalenko, V. Agapov, A. Sochilina, B. Lipatov, Yu. Gorshenkov, E. Molotov, G. Tuccari, S. Buttaccio, X. Liu, J. Zhang, X. Hong, X. Huang, A. Kus, K. Borkowski, Z. Sika, V. Abrosimov, A. Tsyukh, V. Samodurov, I. Falkovich, L. Litvinenko, V. Stepaniants, A. Dementiev, A. Antipenko, S. Snegirev, M. Nechaeva, A. Volvach, V. Saurin, A. Pushkarev, A. Deviatkin, I. Guseva, P. Sukhov. Radar interferometer measurements of space debris using the Evpatoria RT-70 transmitter. Advances in Space Research, Volume 34, Issue 5, 2004, pp. 884-891. 
	6. Molotov I.E., Nechaeva M.B., Konovalenko A.A., Tuccari G., Liu X., Falkovich I.S., Volvach A.E. et al. VLBI radar method development under LFVN project. Journal of the Central Astronomical Observatory in Pulkovo. Volume 218, 2006, pp. 402-414. 
	7. Volvach A.E., Molotov I.E., Tuccari G. et al. Investigations of the space debris fragments in geostationary area. Kosmichna Nauka i Tekhnologiya, Vol. 12, No. 5/6, p. 50-57 (2006) (In Russian).
	8. Molotov, I.; Agapov, V.; Titenko, V.; Khutorovsky, Z.; Burtsev, Yu.; Guseva, I.; Rumyantsev, V.; Ibrahimov, M.; Kornienko, G.; Erofeeva, A.; Biryukov, V.; Vlasjuk, V.; Kiladze, R.; Zalles, R.; Sukhov, P.; Inasaridze, R.; Abdullaeva, G.; Rychalsky, V.; Kouprianov, V.; Rusakov, O.; Litvinenko, E.; Filippov, E. International scientific optical network for space debris research, Advances in Space Research, Volume 41, Issue 7, 2008. p. 1022-1028.
	9. Agapov  V., Schildknecht T., Akim E., Molotov I., Titenko V., Yurasov V. Results of GEO space debris studies in 2004-2005. 57th IAC Final Papers DVD, Valencia, Spain, October 2-6, 2006, 15 pages, IAC-06-B6.1.12.
	10. Igor Molotov, Maria Nechaeva, Igor Falkovich, Vladimir Agapov, Gino Tuccari, Giuseppe Pupillo, Stelio Montebugnoli, Gennadiy Kharlamov, Lance Benner, Viacheslav Fateev, Alexander Volvach, Xiang Liu, Ivars Shmelds, Alexander Dementiev, Nikolay Dugin, Vladimir Jazykov. Astrometry of the Solar System Bodies with VLBI Radar. Book of abstract of the 5th General Meeting of the International VLBI Service for Geodesy and Astrometry. March 2-6, 2008, St.-Petersburg, Russia, pp.  9-10.
11. M.B. Nechaeva, V.G. Gavrilenko, Yu.N. Gorshenkov, B.N. Lipatov, Liu Xiang, I.E. Molotov, A.B. Pushkarev,  R. Shanks. VLBI-observations of Solar Wind Plasma by the method of radio raying; theory and experiments Multi-Wavelength Investigations of Solar Activity, IAU Symposium No. 223, Cambridge University Press, 2004, pp. 655-656. 
12. M. B. Nechaeva, A. A. Antipenko, A. F. Dement'ev, N. A. Dugin, S. D. Snegirev, and Yu. V. Tikhomirov. VLBI studies at the Radiophysical Research Institute. Radiophysics and Quantum Electronics, Vol. 50, No. 7, 2007, pp. 
13. Gavrilenko V. G., Nechaeva M.B., Pushkarev A.B., Molotov I.E., Tuccari G., Chebotarev A.S., Gorshenkov Yu.N., Samodurov V.A., Hong X., Quick J., Dougherty S., Ananthakrishnan S. Results of theoretical and experimental studies of solar wind and active galactic nuclei on LFVN VLBI network using S2 recording  system. Radiophysics and Quantum Electronics, Vol. 50, No. 4, 2007, pp. 253-273.