dr. R.T. Rajan

Assistant Professor
Circuits and Systems (CAS), Department of Microelectronics

PhD thesis (Oct 2016): Relative Space-Time Kinematics of an Anchorless Network
Promotor: Alle-Jan van der Veen

Expertise: Navigation, Sensor fusion, Space systems

Themes: Autonomous sensor systems, XG - Next Generation Sensing and Communication


Raj is an assistant professor with the faculty of electrical engineering, mathematics and computer science (EEMCS) at the Delft university of technology (TUD). His research interests lie in statistical inference and machine learning, with applications to distributed and autonomous sensor systems e.g., satellite arrays for space-based interferometry. He received his PhD in 2016 from the CAS group at TUD, for addressing signal processing challenges of space-based radio astronomy. Previously, he held research positions with diverse responsibilities at IMEC (Eindhoven, 2015-2018), University of Twente (Enschede, 2014), ASTRON (Dwingeloo, 2008-2014), CERN (Geneva, 2007-2008), Politenico di Bari (Bari, 2007-2008), Whirlpool (Pune, 2006-2007), and TIFR-NCRA (Pune, 2005).

If you are interested in pursuing a Master thesis, then drop an email with (a) your interests+passion (b) resume and (c) course list (e.g., IEP, without grades). If you are looking for a PhD position, or interested in collaboration, or just curious about ongoing projects, then do reach out to me via email !

EE2L21 EPO-4: "KITT" autonomous driving challenge

Make a car drive autonomously from A to B

EE3350TU Introduction to Radio Astronomy

Introduction to the science and technology of radio astronomy

EE4C02 Systems Engineering

Introduction to systems engineering processes

ET4386 Estimation and detection

Basics of detection and estimation theory, as used in statistical signal processing, adaptive beamforming, speech enhancement, radar, telecommunication, localization, system identification, and elsewhere.

Delft Sensor AI Lab

AI for sensor networks

Airborne data collection on resilient system architectures

Develop algorithms to realize efficient, robust, cost-effective perception and control for autonomous navigation of drones

PIPP OLFAR: Breakthrough technologies for Interferometry in Space

Combine multiple satellites into one single scientific instrument: a radio telescope in space

Projects history

Low-frequency distributed radio telescope in space

Below 15 MHz, the ionosphere blocks EM signals from the sky. Therefore, can we design a radio telescope in space, using a swarm of inexpensive nano-satellites? Accurate localization and clock recovery is important.

  1. Applications and Potentials of Intelligent Swarms for magnetospheric studies
    Raj Thilak Rajan; Shoshana Ben-Maor; Shaziana Kaderali; Calum Turner; Mohammed Milhim; Catrina Melograna; Dawn Haken; Gary Paul; Vedant; V. Sreekumar; Johannes Weppler; Yosephine Gumulya; Riccardo Bunt; Asia Bulgarini; Maurice Marnat; Kadri Bussov; Frederick Pringle; Jusha Ma; Rushanka Amrutkar; Miguel Coto; Jiang He; Zijian Shi; Shahd Hayder; Dina Saad Fayez Jaber; Junchao Zuo; Mohammad Alsukour; Cécile Renaud; Matthew Chris;
    Acta Astronautica,
    2021. DOI: https://doi.org/10.1016/j.actaastro.2021.07.046
    Keywords: ... Satellite swarms, Intelligent swarms, Heliophysics, Magnetosphere, Cubesats, Next generation space systems.

    Abstract: ... Earth’s magnetosphere is vital for today’s technologically dependent society. To date, numerous design studies have been conducted and over a dozen science missions have flown to study the magnetosphere. However, a majority of these solutions relied on large monolithic satellites, which limited the spatial resolution of these investigations, as did the technological limitations of the past. To counter these limitations, we propose the use of a satellite swarm carrying numerous and distributed payloads for magnetospheric measurements. Our mission is named APIS — Applications and Potentials of Intelligent Swarms. The APIS mission aims to characterize fundamental plasma processes in the Earth’s magnetosphere and measure the effect of the solar wind on our magnetosphere. We propose a swarm of 40 CubeSats in two highly-elliptical orbits around the Earth, which perform radio tomography in the magnetotail at 8–12 Earth Radii (RE) downstream, and the subsolar magnetosphere at 8–12 RE upstream. These maps will be made at both low-resolutions (at 0.5 RE, 5 s cadence) and high-resolutions (at 0.025 RE, 2 s cadence). In addition, in-situ measurements of the magnetic and electric fields, plasma density will be performed by on-board instruments. In this article, we present an outline of previous missions and designs for magnetospheric studies, along with the science drivers and motivation for the APIS mission. Furthermore, preliminary design results are included to show the feasibility of such a mission. The science requirements drive the APIS mission design, the mission operation and the system requirements. In addition to the various science payloads, critical subsystems of the satellites are investigated e.g., navigation, communication, processing and power systems. Our preliminary investigation on the mass, power and link budgets indicate that the mission could be realized using Commercial Off-the-Shelf (COTS) technologies and with homogeneous CubeSats, each with a 12U form factor. We summarize our findings, along with the potential next steps to strengthen our design study.


  2. A roadmap towards a space-based radio telescope for ultra-low frequency radio astronomy
    M.J. Bentum; M.K. Verma; R.T. Rajan; A.J. Boonstra; C.J.M. Verhoeven; E.K.A. Gill; A.J. {van der Veen}; H. Falcke; M. Klein Wolt; B. Monna; S. Engelen; J. Rotteveel; L.I. Gurvits;
    Advances in Space Research,
    Volume 65, Issue 2, pp. 856-867, 2020. High-resolution space-borne radio astronomy. DOI: https://doi.org/10.1016/j.asr.2019.09.007

  3. Lunar Orbit Design of a Satellite Swarm for Radio Astronomy
    Mok, Sung-Hoon; Guo, Jian; Gill, Eberhard; Rajan, Raj Thilak;
    In 2020 IEEE Aerospace Conference,
    pp. 1-9, 2020. DOI: 10.1109/AERO47225.2020.9172468

  4. Autonomous Mission Planning for OLFAR: A Satellite Swarm in Lunar Orbit for Radio Astronomy
    Mok, S; Guo, J; Gill, EKA; Rajan, RT;
    In 71st International Astronautical Congress (IAC),
    IAF/AIAA, 2020.

  5. APIS: Applications and Potentials of Intelligent Swarms for magnetospheric studies
    R.T. Rajan; S. Ben-Maor; S. Kaderali; Others;
    In 71th International Astronautical Congress (IAC),

  6. End-of-life of satellite swarms
    Turner, Calum; Raj Thilak Rajan;
    In 71st International Astronautical Congress (IAC),
    IAF/AIAA, 2020.

  7. Relative kinematics of an anchorless network
    R. T. Rajan; G. Leus; A.J. van der Veen;
    Signal Processing,
    Volume 157, pp. 266-279, April 2019. ISSN: 0165-1684. DOI: 10.1016/j.sigpro.2018.11.005

  8. Low-frequency observations using high-altitude balloon experiments (LOBE)
    Raj Thilak Rajan; P.Sundaramoorthy; C.J.C.Vertegaal; A.Montagne; V.Karunanithi; M.K.Verma; M.Bentum; C.Verhoeven;
    In 70th International Astronautical Congress (IAC),
    IAF, October 2019.

  9. High Data-Rate Inter-Satellite Link (ISL) For Space-Based Interferometry
    Visweswaran Karunanithi; Raj Thilak Rajan; P.Sundaramoorthy; M.K.Verma; C.Verhoeven; M. Bentum; E.W. McCune;
    In 70th International Astronautical Congress (IAC),
    IAF, October 2019.

  10. Multiresolution Time-of-arrival Estimation from Multiband Radio Channel Measurements
    T. Kazaz; R.T. Rajan; G.J.M. Janssen; A.J. van der Veen;
    In 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP),
    Brighton, UK, IEEE, pp. 4395-4399, May 2019. ISBN: 978-1-4799-8132-8. DOI: 10.1109/ICASSP.2019.8683601

  11. Reference-Free Calibration in Sensor Networks
    Raj Thilak Rajan; Rob-van Schaijk; Anup Das; Jac Romme; Frank Pasveer;
    IEEE Sensor letters,
    Volume 2, Issue 3, pp. 1-4, Sept. 2018. DOI: 10.1109/LSENS.2018.2866627

  12. Relative Space-Time Kinematics Of an Anchorless Network
    R.T. Rajan;
    PhD thesis, TU Delft, Fac. EEMCS, October 2016.

  13. Joint ranging and synchronization for an anchorless network of mobile nodes
    R.T. Rajan; A.J. van der Veen;
    IEEE Tr. Signal Processing,
    Volume 63, Issue 8, pp. 1925--1940, April 2015.

  14. Joint relative position and velocity estimation for an anchorless network of mobile nodes
    R.T. Rajan; G. Leus; A.J. van der Veen;
    Signal Processing,
    Volume 115, pp. 66-78, October 2015. DOI: 10.1016/j.sigpro.2015.02.023

  15. Space-based Aperture Array For Ultra-Long Wavelength Radio Astronomy
    R.T. Rajan; A.J. Boonstra; M. Bentum; M. Klein-Wolt; F. Belien; M. Arts; N. Saks; A.J. van der Veen;
    Experimental Astronomy,
    December 2015. DOI: 10.1007/s10686-015-9486-6

  16. Joint Clock Synchronization and Ranging: Asymmetrical Time-stamping and Passive Listening
    S.P. Chepuri; R.T. Rajan; G. Leus; A.J. van der Veen;
    IEEE Signal Processing Letters,
    Volume 20, Issue 1, pp. 51-54, January 2013.

  17. Synchronization for space based ultra low frequency interferometry
    R.T. Rajan; M.J. Bentum; A.J. Boonstra;
    In IEEE Aerospace Conference,
    Big Sky, Montana, US, IEEE, March 2013.

  18. Distributed correlators for Interferometery in space
    R.T. Rajan; M.J. Bentum; A. Gunst; A.J. Boonstra;
    In IEEE Aerospace Conference,
    Big Sky, Montana, US, IEEE, March 2013.

  19. Joint Non-Linear Ranging and Affine Synchronization Basis for a Network of Mobile Nodes
    R.T. Rajan; A.J. van der Veen;
    In Proc. 21st European Signal Processing Conference (EUSIPCO),
    Marrakech (Marokko), September 2013.

  20. Relative velocity estimation using Multidimensional Scaling
    R.T. Rajan; G.J.T. Leus; A.J. van der Veen;
    In Proc. 5th IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP 2013),
    St. Maarten (Dutch Antilles), December 2013.

  21. The Road To OLFAR - A Roadmap To Interferometric Long-Wavelength Radio Astronomy Using Miniaturized Distributed Space Systems
    S. Engelen; K.A. Quillien; C. Verhoeven; A. Noroozi; P. Sundaramoorthy; A.J. van der Veen; R.T. Rajan; A.J. Boonstra; M. Bentum; A. Meijerink; A. Budianu;
    In IAC 2013,
    Beijing, China, September 2013.

  22. Joint motion estimation and clock synchronization for a wireless network of mobile nodes
    R.T. Rajan; A.J. van der Veen;
    In Proc. IEEE ICASSP,
    Kyoto (Japan), IEEE, pp. 2845-2848, May 2012.

  23. Orbiting Low Frequency Antenna Array for Radio Astronomy
    R.T. Rajan; S. Engelen; M.J. Bentum; C.J.M. Verhoeven;
    In IEEE Aerospace Conference,
    Montana, USA, pp. 1-11, March 2011. DOI: 10.1109/AERO.2011.5747222

  24. Joint ranging and clock synchronization for a satellite array
    R.T. Rajan; A.J. van der Veen;
    In Proc. SPAMEC,
    Cluj-Napoca (Romania), Eurasip, August 2011.

  25. Joint ranging and clock synchronization for a wireless network
    R.T. Rajan; A.J. van der Veen;
    In 4th IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP),
    Puerto Rico, IEEE, pp. 297-300, December 2011. ISBN 978-1-4577-2103-8.

  26. OLFAR, Adaptive topology for satellite swarms
    A. Budianu; R.T. Rajan; S. Engelen; A. Meijerink; C.J.M. Verhoeven; M.J. Bentum;
    In IAC 2011,
    Cape Town, October 2011.

BibTeX support

Last updated: 28 Oct 2021