Radio location observations of space debris in VIRAC

1. Radio location observations of space debris in VIRAC Vl. Bezrukovs, I. Šmelds, M. Ņechaeva, D. Bezrukovs, N. Jekabsons, M. Abele, D. Kotlere Ventspils University College, Latvia Expanding the Universe Conference in Tartu 28 April 2011

2. Outline • Ventspils International Radio Astronomy Center (VIRAC). • VIRAC history and new challenges. • Project "Signals related to Artificial Earth Satellites: Technologies of Receiving, Transmitting and Processing“. • Irbene Radio telescope RT-32 preparation for observations. • Space debris observation experiment VLBR10.1, 30 of June of 2010,

3. Ventspils International Radio Astronomy Center (VIRAC)

4. Ventspils International Radio AstronomyCenter RT-2 Ventspils University College Kristals RT-16 RT-32

5. EngineeringResearchInstitute“Ventspils International Radioastronomy Center” (ERI VIRAC)History 1950. – the secret Soviet military space center is established. 1960. – 1970. two parabolic antennas with diameters 32 (RT-32) and 16 (RT-16) meters are built 1994. after withdrawal the Soviet Army antennas become to Latvian Academy of Science. Telescopes are heavy damaged, any documentation is absent. Soon VIRAC is established. 1998. First antenna movement and radio astronomical observations 2004. VIRAC merges with VUC 2010.VIRAC mergesEngineeringResearchInstititute of VUC.Engineering Research Institute “Ventspils InternationalRadioastronomyCenter” is established.

6. Ventspils International Radio AstronomyCenter Applied research in the space field Fundamental research in astronomy and astrophysics • Satellite navigation and satellite communication research • Satellite navigation (GPS, Galileo, GLONASS) • Space geodesy • Satellite signal processing • Space communications • Satellite data processing • Signal and image processing • Satellite components research and development • Very Long Base Line Interfereometry (VLBI) • European VLBI Network (EVN) • Low Frequency VLBI Network (LFVN) • Space debris and small planets radiolocation • Astrophysics and astrometry research • Solar radio astronomy • Astrochemistry • Active galactic Nuclei Applied engineering and electronics High performance computing • VLBI data processing and modeling • Radiotelescope RT-32 and RT-16 control system optimization • MHD modeling and solid-state mechanics • Mathematical modeling • Medical engineering • Fast prototyping research laboratory • Renewable energy research and energy efficiency studies • Small power generators • Wind energy research • Intelligent network studies • Smart house applications • Digital TV applications • Economical studies group

7. COOPERATION/PARTNERS/PROJECTS The European VLBI Network (EVN) is an interferometric array of radio telescopes spread throughout Europe (and beyond) that conducts unique, high resolution, radio astronomical observations of cosmic radio sources. It is the most sensitive VLBI array in the world, thanks to the collection of extremely large telescopes that contribute to the network.

8. COOPERATION/PARTNERS/PROJECTS • Project “Signals related to Artificial Earth Satellites: Technologies of Receiving, Transmitting and Processing” • (2009 – 2012) Activities of the project: The Reconstruction of the telescope RT-16, research in the fields of electronics, mechanics and mathematical modeling The Development and application of methods for processing the recorded data Space debris radiolocation using the radio telescope RT-32 and the VLBI techniques Software correlator for VLBI data processing and software for computing the orbital elements and future coordinates of the observed objects (debris). Collaboration withRadio physical Research Institute, Nizhnij Novgorod, Russia and LFVN More than 20 researchers involved within the project

9. Low Frequency VLBI Network Project (LFVN) • Radio Telescopes: • BearLakes RT-64 • Pushchino RT-22 • Zimenki RT-15 • St. Pustyn RT-14 (Russia) • Evpatoria RT-70 • Simeiz RT-22 (Ukraine) • Noto RT-32 • Medicina RT-32 (Italy), • Urumqi RT-25 (China), • Ventspils RT-32 (Latvia). • Frequencies: • 92 cm, 18 cm, 6 cm. • Recording systems: • TN16, MK-2, NRTV, MK-V. • Activities: • Investigationsofsolarwind, solarspikes, AGN, OH-masers, active stars andradarresearchofEarthgroupplanets, closeasteroidsandspacedebrisobjects.

10. VLBI radar method VLBI-radar method since 2001 is applied for determination of path of planets, asteroids and space debris objects(disabled satellites, rocket stages, etc.). The VLBI radar method represents the combination of the "classic" radar and VLBI. As a result, such combination gives the instruments, which can measure the range, radialvelocity (like radar) and the angle and angular velocity(like VLBI). The main task of the experiments is the receiving of information about object’s coordinates and velocityon measurements of time delay and Doppler frequency. Planet radar RT-70 (Evpatoria, Ukraine)

11. VLBI radar method Transmitting antenna Data Processing Center Receiving antennas During VLBI radar experimentthe planet radar irradiates the space object, and the array of radio telescopes receives the reflected from object signal in VLBI mode. • VIRACtook part in radar VLBI experiments since 2007 on LFVN, including: • planet radar in Evpatoria, Ukraine:RT-70, F=5 GHz, P=20-60kW (continuous regime of emission); • VLBI-sites: • RT-64 (Kalyazin, Russia), RT-22 (Simeiz, Ukraine), RT-32 (Noto, Italy), RT-32 (Medicina, Italy), RT-25 (Urumqi, China) and RT-32 (Irbene, Latvia) • Data processing centre “NIRFI-3” (Nizhnij Novgorod, Russia)

12. VLBI-stationRT-32 (Irbene, VIRAC) 57.553 N, 21.855E • VLBI-equipment: • Working frequency range: • 327, 5’010, 12’000MHz • Frequency converter:DBBC, MK-II • Recording system: • MK-V B,TN-16, MK-II • Synchronization system: • Hydrogen Maser “Quartz” CH-75A, synchronized by GPS

13. 5 GHz receiving system on RT-32 Signalreceivingandregistrationsystemonradiotelescope RT- 32 (forobservationsofspacedebrisandbodiesofsolarsystem) TN-16, and Mark II areanalog-digitalconverters Registrationsystemwillbeupgardedto DBBC with Mark 5b system

14. 5 GHz receiver preparation and installation works on RT-32 • RT-32 telescope focal cabin reconstructed; • new shelves for equipment; • RF and power connection; • Heated, hermetic room for receiving equipment prepared; • Created and installed new system for precise receiver alignment; • Feeder for 5 GHz receiver mounted; • 5 GHz cryogenic receiver mounted, connected and tested;

15. 5 GHz receiver calibration Receiving system at 5GHz with recording terminal TN-16 was calibrated using external signal generator and is suitable for VLBI experiments . Example of power spectra from 5.01 GHz signal autocorrelation. Frequency 250 kHz, bandwidth 0.5 MHz. (29.06.2010).

16. Experiment VLBR 10.1 • VLBR10.1, 30 of June of 2010, 09:04 – 17:00 UT • Transmission mode (Evpatoria locator on RT-70, Ukraine): • Monochromatic radiation; • central frequency of 5010.024 MHz, • polarization RCP, • power P=40 kW • Observational mode: • Bandwidth: 500 KHz • Central frequency: 5010.0 MHz • Polarization: RCP and LCP (Medicina, RT-32, Italy), • LCP(Ventspils, RT-32, Latvia) • Recording systems: • Mark-V(Medicina), • TN-16, Mark-II (Ventspils) • The data processing is carried out simultaneously in Medicina and Nizhnij Novgorod and in the VIRAC corelator (test)

17. Experiment VLBR 10.1 The scientific tasks of experiment: • Investigations of space debris (Iridium-Cosmos and Fengyun 1C fragments) in LEO; • Several LEO regions for searching not yet catalogued debris; • High Area/Mass debris in GEO; • Astronomical and radar calibrators.

18. Experiment VLBR 10.1 Frequency of Doppler shift calculation The samples of power spectrum, calculated from correlation of transmitter signal and signal, reflected from space debris object “35303” and received by RT-32 (Irbene) Frequency of Dopplershift is calculated from spectral maximum. Data processing was performed in NIRFI

19. Experiment VLBR 10.1 Preliminary results: Calculated Doppler shift relative to observation point for detected objects

20. Conclusions and future plans related to space debris • Development of the ground station for radio location observations of space debris and asteroids on the basis of the radio telescope RT-32 with collaboration with LFVN and other VLBI networks • Development of the software correllator for observation data processing and correlation on the basis of the Ventspils University College cluster. • Develop software package development for computing the orbital elements and future coordinates of the observed objects (with collaboration with Latvian University • Prepare and manage space debris observational sessions • The expected accuracy of objects of space debris position and velocity measurements are up to some cm and up to several mm/sec.

21. In collaboration with: NikolajDugin,Radiophysical Research Institute, Nizhnij Novgorod, Russia; GuntisOzoliņš, VIRAC; and all other VIRAC team. Giuseppe Pupillo, Istitutodi Radioastronomia, ItalyStelioMontebugnoli, OsservatorioAstronomico di Torino, IstitutoNazionale di Astrofisica,  ItalyАлександр Коноваленко, Радиоастрономический институт национальной академии наук Украины, Харьков.Национальный центр управления и испытания космических средств, Евпатория, Украина Thank you for attention. Nr.2009/0231/1DP/1.1.1.2.0/09/APIA/VIAA/151