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Prof. Rajendar Bahl

Professor

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Rajendar Bahl
  • About
  • Research Interest
  • Contact Information
  • Funded Project
  • Student Project
  • PhD Scholar
  • Publication

About

Rajendar Bahl has a B.Tech (Honours) in Electronics and Electrical Communication Engineering from IIT Kharagpur (1974) and Ph.D (EE) from IIT Delhi (1982). He has been a past Head of the Centre during 1996-99. He has participated in various national bodies of the Department of Electronics, Ministry of Information Technology, and the Defence Research & Development Organisation. He was jointly awarded the 1982 Invention Award of the National Research & Development Corporation for the indigenous development of a Digital Control System. He won a Senior Fellowship award of the US National Research Council during 1989-90 at the Naval Postgraduate School, Monterey. He has also been a Visiting Professor in the field of bio-acoustics at the Institute of Industrial Science, University of Tokyo, Japan during 2002-2004. His major expertise is in sonar design and he has implemented a number of projects in this area.

Courses Offered

  • EEL765 - Sonar System Engineering

  • CRL731 - Selected Topicsin RFDT-I (Imaging Sonars)

ACHIEVEMENTS IN SONAR TECHNOLOGY RESEARCH

  • Developed a unique Dolphin Tracking technology using Passive Acoustic Monitoring in collaboration with University of Tokyo. System has been deployed in the Ganges river for monitoring Ganges dolphins at Narora, UP, since 2008.
  • Developed algorithms for Classification and Tracking of Sperm Whales from their Click Sounds. Joint work at University of Tokyo as Guest Professor. Conducted field experiments off Ogasawara Islands in Pacific Ocean for passive tracking multiple diving whales.
  • Techniques for Automatic Recognition of Humpback Whales from their Songs. Joint work at University of Tokyo as Guest Professor.
  • Designed a unique Autonomous Humpback Whale Song Tracking Sonar. Joint work at University of Tokyo as Visiting Researcher.
  • Designed a unique Programmable Test Signal Generator for Sonars.Developed for use as a test-bed for real-time testing of Sonars in realistic scenarios.
  • LOW POWER MULTI-DSP PLATFORM FOR ACOUSTIC SIGNAL PROCESSING

A reconfigurable multi-DSP hardware platform with built-in self test (BIST) capabilities has been designed and fabricated.
  • SONAR 170B MODIFICATION

A modification for Sonar 170B was successfully carried out. This gaveimproved performance in reverberation limited conditions. The mod-kit has been productionised by M/s BDL Hyderabad.
  • SONAR 311 MODIFICATION

A complete receiver for Petya Sonar 311 has been developed. Incorporating digital processing and own-doppler nullification. This receiver was successfully proved at sea trials and gave designed performance.
  • OMNI-DIRECTIONAL SONAR RECEIVER

A Compact Multiplexed Multichannel SONAR receiver (ODS) has been designed. This panoramic sonar uses advanced DSP techniques for front end processing, beamforming, own doppler nullification, display processing, target parameter speak out etc. The sonar underwent successful sea trials.
  • UNDERWATER DATA TELEMETRY LINK

A microprocessor based data communication link for telemetry has been designed. The system has been demonstrated in the laboratory.
  • UNDERWATER ACOUSTIC IMAGING SYSTEM

An acoustic data acquisition system for imaging applications has been designed. The system is configured for a 16x16 element planar array. The sensor data is acquired and passed onto an IBM PC for image reconstruction.
  • HIGH RESOLUTION SECTOR SCANNING SONAR

A complete high resolution sector scanning sonar at a frequency of 300 KHz has been developed. This sonar has been successfully tested at field trials at UARF Idukki, Kerala. The sonar has a range resolution of 7.5 cm and bearing resolution of 0.7 degrees.

Research Interest

Professor Bahl has authored a concept called "Comprehensive Ocean Area Surveillance Technology" (COAST) that consists of a network of autonomous underwater observatories that collect and process acoustic data and communicate over acoustic wireless links with a base station, or through RF link to an overhead aircraft or satellite. Several techniques and technologies to realise COAST have been developed by his team at IIT Delhi: when operationalized, it will be a first such indigenous development of its kind.

His other ongoing research interests are:

  • Sensor System Design and Simulation

  • Acoustical Imaging

  • Bio Sonar

Current R&D Activities

  • Development of MIMO OFDM underwater acoustic data communication links.

  • Passive surveillance techniques for autonomous platforms: development of Vector Sensors.

  • Design and Development of a prototype compact low-powered acoustic signal processor module for remote platforms.

  • Infrasonic detection of snow avalanches

  • Active and Passive Sonar Performance evaluation in bounded channels.

Contact Information

Email rbahl@care.iitd.ernet.in
Telephone (O) +91-11-26591103
(R) +91-11-26591838
Facsimile +91-11-26591103
Address Centre for Applied Research in Electronics,
Indian Institute of Technology, Delhi
Hauz Khas, New Delhi - 110 016, INDIA

Funded Projects

  1. R. Bahl, A. Kumar, M. Agarwal,"Realization of prototype low power acoustic signal processor module for remote manned / unmanned platforms",Rs. 4800000, 2006-2008.

  2. R. Bahl, A. Kumar,M. Agarwal,"Design and implementation of target detection module for underwater passive surveillance",Rs. 2100000, 2006-2008.

  3. R. Bahl, A. Kumar, M. Agarwal, "Upgradation of laboratory facilities in the area of Underwater Electronics at CARE", Rs.7800000, 2005-2010.

  4. R. Bahl, A. Kumar, M. Agarwal,"Design of platform classifier using multi-sensor data fusion," Rs. 1450000, 2005-2006.

  5. R. Bahl, A. Kumar, M. Agarwal, "Design of target classification method for passive surveillance sonar", Rs. 18,50,000, 2003-2006.

  6. R. Bahl, S. Tuli, A.Kumar and G. Bose,"Novel studies on propagation and signal processing of thermal waves for defect localization with applications to non-destructive characterization," Rs. 47,38,000, 2002-2005.

  7. R. Bahl and A. Kumar," Study and simulation of passive surveillance techniques for autonomous platforms," Rs. 9.0 Lakhs, 2000-2002.

  8. R. Bahl and A. Kumar,"Development of techniques for low probability of intercept secure underwater LAN links," Rs. 9.0 Lakhs, 2000-2002.

  9. R. Bahl and A. Kumar, "Design and development of a prototype compact low-power acoustic signal processor module for remote manned/unmanned platforms",Rs. 9.5 Lakhs,2000-2002.

  10. A. Kumar and R. Bahl,"Investigations of novel designs for efficient wideband speech and audio coding",Rs. 7.0 Lakhs, 1999-2001.

  11. A. Kumar and R. Bahl, Design of efficient wideband speech encoding and decoding scheme, Rs. 7.0Lakhs, 1998-1999

Consultancy Projects

  1. Bahl, A. Kumar, M. Agarwal,"Identification of coupled machinery frequencies from passive sonar data", NSTL, DRDO,Vishakhapatnam, Rs. 950000, 2006-2008.

  2. R. Bahl, A. Kumar, M. Agarwal,"Noise filtering and spectral estimation techniques for passive sonar data", NSTL, DRDO,Vishakhapatnam, Rs. 950000, 2006-2008.

  3. A. Kumar, R. Bahl,"Spatial mapping of source from passiv sonar data",NSTL, DRDO, Vishakhapatnam, Rs. 950000,2006-2008.

  4. A. Kumar, R. Bahl,"Formulating realistic criteria for detection of targets by sonars", Macmet Technologies Limited, Bangalore, Rs. 900000, 2005-2006.

  5. Kumar and S. Prakriya, "Modular course in Digital Signal Processing," LRDE, DRDRO, Bangalore, Rs. 3.00 Lakhs, 2003.

  6. R.Bahl and A. Kumar, "Training simulation software for naval applications",� MACMET India Ltd., Bangalore, Rs. 3.50 Lakhs, 2002

  7. R. Bahl and A. Kumar,"DSP Consultation",� ST Microelectronics, Noida, Rs. 1.06Lakhs, 2000.

  8. A. Kumar and R. Bahl, "Robust algorithm design for natural quality low bit rate speech coding",Silicon Automation Systems, Bangalore, Rs. 2.40 Lakhs, 1998-1999.

  9. A. Kumar and R. Bahl, "Algorithm design of speech encoder and decoder at 3.0-4.0 kbps",Silicon Automation Systems, Bangalore, Rs. 1.0 Lakhs, 1998.

  10. A. Kumar and R. Bahl,"Design of speech coder", Hughes Software Systems, Gurgaon,Rs. 3.80 Lakhs, 1998.

  11. A. Kumar and R. Bahl, "Algorithm design and DSP implementation of variable rate speech encoder and decoder at 3.0-4.0 kbps",� Silicon Automation Systems,Bangalore, Rs. 2.40 Lakhs, 1997.

Master's Major Projects

  1. Arshdeep Singh Ahluwalia, "Design and development of classification and data fusion algorithms for radar and sonar applications",2006.

  2. V. Kishore, "Simulation of ship radiated noise and classification using neural networks and K-nearest neighbours," 2006.

  3. Abhishek Singh, "Hybrid detector for ship radiated signal in statistically varying underwater noise" , 2006.

  4. Ajit Pal Singh, "Design of low power acoustic signal processor module with built-in-self test (BIST) facility," 2005.

  5. Sougata Maitra, "Implementation of interfaces and design of a non-preemptive real time operating system for low power acoustic signal processing module,", 2005.

  6. J. Senthil Rengarajan, "Implementation of sonocular perception system using TMS320VC5510 DSK,", 2005.

  7. Rahul Kapoor, "Underwater radiated noise synthesis and detection and classification of transients".

  8. Rajan Dhiman, "Design of a prototype low power acoustic signal processor module for remote manned/unmanned platforms," , 2001.

  9. Rajesh K. Nair, "Design and simulation of underwater acoustic LAN protocols,", 2001.

  10. Amitabh Pandey, "Studies on passive sonar processing and ocean acoustic propagation modeling,", 2001.

  11. Subhash Yadav,"Study of PC to PC infrared data communication link (IRDA),",2001.

  12. Harjit S. Chatha,"Simulation of underwater communication system operation in shallow oceanic channel,", 2001.

  13. T. Ajit, "Study and proposal of an underwater acoustic local area network", 2000.

  14. M S. Pental," Studies on the design of a low power acoustic signal processor module for remote manned/unmanned platform", 2000.

  15. K. Raja," Ocean acoustic propogation modelling - The ray trace and normal mode methods", 2000.

  16. R. Chatrath,"A task scheduling simulator for multiple DSP board systems", 2000.

  17. A. Saxena,"Study of low probabilty of intercept and robust underwater acoustic communications", 2000.

  18. A. M. Anand,"Simulator for multiprocessor based systems", 1999.

  19. S.N. Singh,"Simulation of underwater acoustic channel and study of Frank polyphase code for receiver synchronization", 1999.

  20. Vivin Vaid,"VHDL based simulation of USART (INTEL 8251A)", 1999.

  21. Ajay Tiwari,"Study and simulation of shallow water sound propogation", 1999.

  22. Subramanian, "Study and simulation of underwater networking",1998.

  23. R. K. Goswami,"Simulation and design of autonomous passive sonar", 1998.

  24. Ashish Pathak, "Simulation study and DSP implementation of digital radio receiver",1998.

  25. Rajesh Sharma, "Channel simulation and detection of underwater targets", 1997.

  26. Vikesh Jain, "Synthesis of scenario signals for Sonar performance evaluation",1995.

  27. Sanjay Ojha, "Integration of programmable and self-testable Sonar",1995, supervised by R. Bahl.

  28. Akash Kapoor, "FPGA-ADSP2111 based programmable signal synthesiser", 1995, supervised by R. Bahl and H. Sirpal.

  29. HR Ansingkar, "Software simulator for multi-processor DSP board", 1996, supervised by R. Bahl.

  30. K Jadia, "Software for simulation of Sonar echo from point and extended targets", 1996, supervised by R. Bahl.

  31. Shrotriya, "Design and implementation of bus controller and arbiter on FPGA", 1996, supervised by R. Bahl.

  32. V. Kumar, "Modelling of a torpedo test range", 1996, supervised by R. Bahl.

  33. K. De, "A reconfigurable architecture for programmable interconnected DSPs", 1996, supervised by R. Bahl.

  34. D.N. Singh, "Multilayer PCB design for imaging Sonar DSP boards", 1996, Supervised by R. Bahl.

  35. S Lota, "Design of 8 Bit CMOS multiplying digital to analog converter", 1997, supervised by AB Bhattacharyya and R Bahl.

  36. Munish Sharma, "Application development interface for RAPID card", 1997, supervised by R. Bahl.

  37. Rajesh Sharma, "Channel simulation and detection of underwater targets", 1997, supervised by R. Bahl and Arun Kumar.

  38. Rajveer Singh, "Signal processing algorithms for SHARC based Sonar for object identification", 1997, supervised by R. Bahl.

  39. Sanjay Sharma, "Design, implementation and testing of digital modulators", 1998, supervised by R. Bahl and Gerard Gielis.

  40. Tanmay Roy, "SHARC based imaging Sonar receiver", 1998, supervised by R. Bahl.

  41. Pathak, "Simulation, study and DSP implementation of digital radio receiver", 1998, Supervised by R. Bahl and Arun Kumar.

  42. RK Goswami, "Simulation and design of autonomous passive Sonar" 1998, supervised by R. Bahl and Arun Kumar.

  43. Ajay Tiwari, "Study and simulation of shallow water sound propagation", 1999, supervised by R. Bahl and Arun Kumar.

  44. Vivin Vaid, "VHDL based simulation of USART(Intel 8251A)", 1999, supervised by R. Bahl and Arun Kumar.

  45. SN Singh, "Simulation of Underwater Acoustic Channel and Study of Frank Polyphase Code for Receiver Synchronization Supervised by R. Bahl and Arun Kumar", 1999.

  46. AM Anand, "Simulator for multiprocessor based system", 1999, supervised by R. Bahl and Arun Kumar.

  47. Ashutosh Tiwari, "DSP implementation of a RAKE receiver", 1999, supervised by R. Bahl and Rob Wubben.

  48. A. Saxena, "Study of low probabilty of intercept and robust underwater acoustic communications", 2000.

  49. R. Chatrath, "A task scheduling simulator for multiple DSP board systems", 2000, supervised by R. Bahl and Arun Kumar.

  50. K. Raja, " Ocean acoustic propogation modelling - The ray trace and normal mode methods", 2000,supervised by R. Bahl and Arun Kumar.

  51. M.S. Pental, " Studies on the design of a low power acoustic signal processor module for remote manned/unmanned platform", 2000,supervised by R. Bahl and Arun Kumar.

  52. T. Ajit, "Study and proposal of an underwater acoustic local area network", 2000, supervised by R. Bahl and Arun Kumar.

In Progress

  • Hemlata Choudhary
    AreaSignal Processing Algorithms for acoustic localization.
    Supervisors: R. Bahl and Arun Kumar.

  • Rinki Gupta
    Area: Signal Procesing Algorithms for frequency estimation.
    Supervisors: R. Bahl and Arun Kumar.

  • Kapil Tyagi
    Area: Processing Algorithms for acoustic reflectometry.
    Supervisors: R. Bahl and Arun Kumar

Completed

  1. Arnab Das,"Marine vessel classification using passive sonar", 2009,
    Supervised by R. Bahl and Arun Kumar.

  2. Tanmay Roy,"Bispectrum phase based extraction of target parameters using passive sonar", 2004,
    Supervised by R. Bahl and Arun Kumar.

  3. L.V.Subramaniam,"On codes over asymmetric PSK and multidimensional uniform signal sets",1999,
    Supervised by R. Bahl and B. Sundar Rajan.

  4. O.George,"Simulation model for backscattering of high frequency sound from complex objects and sand sea bottom", 1999,
    Supervised by R. Bahl.

  5. G. Sudhir,"Cooperative algorithms for stereo and motion analysis"", 1994,
    Supervised by R. Bahl and K.K. Biswas.

  6. Bindu Chandna,"Some contributions to the high-resolution estimation of directions-of-arrival of plane waves", 1990,
    Supervised by R. Bahl and S.Prasad.

Publications

(Since 2000)
  1. Akamatsu T., Ura T., Sugimatsu H., Bahl R., Behera S., Rupak D., Panda S., Khan M., Kar C.S., Kar S.K., Kimura S., Sasaki-Yamamoto Y. , "Abundance estimation of Ganges river dolphins by acoustic-visual mark recapture method," 20th Biennial Conference on the Biology of Marine Mammals, Dunedin, New Zealand, Dec. 9-12, 2013.

  2. Akamatsu T., Ura T., Sugimatsu H., Bahl R., Behera S., Panda S., Khan M., Kar C.S., Kar S.K., Kimura S., Sasaki-Yamamoto Y. , "Acoustic cue detection model for abundance estimation of small odontocetes," The 6th International Workshop on Detection, Classification, Localization, & Density Estimation of Marine Mammals using Passive Acoustics, St Andrews, UK, June 12-15, 2013.

  3. T. Akamatsu, T. Ura, and H. Sugimatsu, R. Bahl, S. Behera, S. Panda and M. Khan, S. K. Kar and C. S. Kar, S. Kimura, Y. Sasaki-Yamamoto, (2013) "Counting Animals Using Vocalizations; a Case Study in Dolphins," Proc. Intl. Symposium Underwater Technology 2013, Tokyo, March 2013.

  4. H. Choudhary, R. Bahl, A. Kumar, "Passive acoustic localization using Gauss Markov estimate with spectral estimation at each sensor," Proc. Intl. Symposium Underwater Technology 2013, Tokyo, Mar. 2013.

  5. H. Parameswaran, R. Bahl, A. Kumar, R. Gupta, "Cross-range imaging of a cooperative source using passive inverse synthetic aperture technique," Proc. Intl. Symposium Underwater Technology 2013, Tokyo, Mar. 2013.

  6. R. Gupta, A. Kumar, R. Bahl, "Motion parameter estimation of a radiating point source with multiple tonals using acoustic Doppler analysis," Proc. Intl. Symposium Underwater Technology 2013, Tokyo, Mar. 2013.

  7. A. Kumar, R. Bahl, H. Choudhary, "Performance enhancement of GMSK and LDPC based VLF communication in the presence of atmospheric noise," Proc. National Conf. on Communications, New Delhi, Feb. 2013.

  8. Arun Kumar and Rajendar Bahl, "An architecture for high data rate very low frequency communication," Defence Science Journal, vol. 63, no. 1, pp. 25-33, Jan 2013.

  9. T. Akamatsu, T. Ura, H. Sugimatsu, R. Bahl, S. Behera, S. Pand, M. Khan, S.K. Kar, C.S. Kar, S. Kimura and Y. Sasaki-Yamamoto, "A multimodal detection model of dolphins to estimate abundance validated by field experiments," J. Acoust. Soc. Am. 134 (3), Pt. 2, pp 2418-2426, September 2013.

  10. A.Das, A.Kumar, R.Bahl, "Marine vessel classification based on passive sonar data: the cepstrum-based approach," IET Radar, Sonar and Navigation, pp. 1–7, doi:10.1049/iet-rsn.2011.0142,June/Jul 2012.

  11. Sugimatsu, H., Ura, T., Mizuno, K., Asada, A., Kojima, J., Bahl, R., Behera, S., Singh, H., Sagar, V.S. ,"Study of acoustic characteristics of Ganges river dolphin calf using ehcolocation clicks recorded during long-term in-situ observation," Proc. IEEE Oceans'12, Hampton Roads, USA, Oct. 14-19, 2012

  12. Sasaki-Yamamoto Y., T. Akamatsu, T. Ura, H. Sugimatsu, J. Kojima, R. Bahl, S. Beher, S. Kohshima, "Diel changes in the movement patterns of Ganges River dolphins monitored using stationed stereo acoustic data loggers," Marine Mammal Science, in press, 2012.

  13. H. Choudhary, R. Bahl, A. Kumar, "Passive acoustic localization using blind Gauss Markov estimate with spectral estimation at each sensor," IET Radar, Sonar and Navigation, Sept. 2012. (accepted)

  14. A.Das, A.Kumar, R.Bahl, "Marine vessel classification based on passive sonar data: the cepstrum-based approach," IET Radar, Sonar and Navigation, (doi:10.1049/iet-rsn.2011.0142) pp.1-7, June/July 2012

  15. Rinki Gupta, Arun Kumar, Rajendar Bahl, "Estimation of instantaneous frequencies using iterative empirical mode decomposition," Signal, Image and Video Processing, Springer [online], doi: 10.1007/s11760-012-0305-5, 24 Mar 2012.

  16. Harumi Sugimatsu, Tamaki Ura, Junichi Kojima, Shizuko Hiryu, Rajendar Bahl, Sandeep Behera, Ajit Pattnaik, Idris Mandan, Sabro Tomuro, Danielle Krebl: "Asian Dolphin Observatories Real-time Networking-ADORN", Proc. Oceans 2012 Yeosu, South Korea, (2012.5), CD-Rom

  17. H. Choudhary, R. Bahl and A. Kumar, "Passive Acoustic Localization using Blind Gauss-Markov Estimate for the Time Delay Vector," Proc. Intl. Symposium on Ocean Electronics, India, pp. 56-62, Nov. 2011.

  18. Harumi Sugimatsu, Tamaki Ura, Junichi Kojima, Rajendar Bahl, Sandeep Behera, Vivek Sheel Sagar "Route selection strategy of the Ganges river dolphins (Platanista gangetica) observed by seasonal long-term real-time monitoring," Abstracts of SMM 2011, Tampa, Florida, USA, CD-Rom, Nov. 2011.

  19. Ryo Hirotsu, Tamaki Ura, Junichi Kojima, Harumi Sugimatsu, Rajendar Bahl, Masao Yanagisawa: "Do sperm whales recognize each other during their dives? Relationship between sperm whales' click range and each distance: do they recognize each other? Relationship between sperm whales click range, distance and seafloor", Abstracts of SMM 2011 Tampa, Florida, USA, (2011.11), CD-Rom

  20. Junichi Kojima, Harumi Sugimatsu, Tamaki Ura, Rajendar Bahl, Sandeep Behera, Vivek Sheel Sagar, "An integrated observation system with multiple acoustic arrays for underwater behavioral study of the Ganges river dolphins", Proc. Oceans11 Santander, Spain, 2011.06, CD-Rom

  21. Harumi Sugimatsu, Junichi Kojima, Tamaki Ura, Rajendar Bahl, Sandeep Behera, Vivek Sheel Sagar, "Annual Behavioral Changes of the Ganges River Dolphins (platanista gangetica) Based on the Three Long-Term Monitoring Seasons using 6-Hydrophone Array System", Proc. UT&SSC11, Tokyo, Japan, 2011.4, CD-Rom

  22. A. Das, A. Kumar and R. Bahl, "Realistic ambient noise analysis for passive surveillance algorithm design", 2011 IEEE Symposium on Underwater Technology, Tokyo, Japan, 2011.4, CD-ROM

  23. Arnab Das, Arun Kumar, and Rajendar Bahl, "Radiated signal characteristics of marine vessels in the cepstral domain for shallow underwater channel", Journal of Acoustical Society of America Express Letters, Vol. 128(4), pp. EL 151-156, October 2010.

  24. Ryo Hirotsu, Masao Yanagisawa, Tamaki Ura, Masao Sakata, and Harumi Sugimatsu, Junichi Kojima, Rajendar Bahl, "Localization of sperm whales in a group using clicks received at two separated short baseline arrays", J. Acoust. Soc. Am. 127 (1), January 2010, pp 133-147

  25. Ashish Agarwal, Arun Kumar, Monika Agarwal and R. Bahl, "Design and experimentation with acoustic vector sensors", Proc. Intl. Symposium on Ocean Electronics, Kochi, Nov. 2009

  26. Arnab Das, Arun Kumar and Rajender Bahl, "Improved estimation of machinery tonal intensity under severe underwater channel distortions", Proc. Intl. Symposium on Ocean Electronics, Kochi, Nov. 2009.

  27. Harumi Sugimatsu, Tamaki Ura, Junichi Kojima, Rajendar Bahl, Sandeep Behera, Takashi Sakamaki, "Long-term Real time monitoring of the Ganges river dolphins(Platanista gangetica)using Integrated Acoustic Observation System", Proc. 21st Ocean Engineering Symposium, Tokyo, Japan, August 2009, (in Japanese).

  28. Harumi Sugimatsu, Tamaki Ura, Junichi Kojima, Rajendar Bahl, Sandeep Behera, Bushra Khan, Vivek Sheel Sagar, "Long-term Real-time Monitoring of the Ganges river dolphins using Integrated Observation System with Multiple Acoustic Arrays", Proc. UT2009, Wuxi, China, April 2009, pp. 214-218.

  29. Ryo Hirotsu, Tamaki Ura, Junichi Kojima, Harumi Sugimatsu, Rajendar Bahl, Masao Yanagisawa, "Classification of Sperm Whale Clicks and Triangulation for Real-Time Localization with SBL Arrays", Proc. OCEAN'S 2008 Quebec, Canada, September 2008.

  30. Harumi Sugimatsu, Tamaki Ura, Junichi Kojima, Rajendar Bahl, Sandeep Behera, "Underwater behavioral study of Ganges river dolphins by using echolocation clicks recorded by 6-hydrophone array system", Proc. OCEAN'S 2008 Quebec, Canada, Sept 2008.

  31. Suleman Mazhar, Tamaki Ura, Rajendar Bahl, "An analysis of Humpback whale songs for individual classification", Abstracts of Acoustics'08 Paris, June 2008, Paris, France.

  32. Yukiko Yamamoto, Tomonari Akamatsu, Tamaki Ura, Harumi Sugimatsu, Junichi Kojima, Rajendar Bahl, Sandeep.K. Behera, A.Pattnaik, M. Khan, S. Kar, C. Kar, Shiro Kohshima, "Behavior pattern analysis of Ganges river dolphin (Platanista gangetica gangetica)", Proc. Comparative Cognitive Science 2008, May 2008, Kyoto, Japan, Poster presentation.

  33. Suleman Mazhar, Tamaki Ura, Rajendar Bahl:, "Effect of Temporal Evolution of Songs on Cepstrum-based Voice Signature in Humpback Whales", Proc. Oceans2008, Kobe, Kobe, Japan, April 2008.

  34. Suleman Mazhar, Tamaki Ura, Rajendar Bahl, "Searching for a lost humpback whale", Abstract of ECS08, Egmond Ann Zee, The Netherlands, March 2008, pp.86-87, poster presentation.

  35. Junichi Kojima, Harumi Sugimatsu, Rajendar Bahl, Tamaki Ura, S. Behera, Tomoki Inoue, Tetsuo Fukuchi, "Study of the Ganges river dolphin's beam pattern", Abstracts of 17th Biennial Conference on the Biology of Marine Mammals, Cape Town, South Africa, Dec 2007, oral presentation.

  36. Ryo Hirotsu, Tamaki Ura, Junichi Kojima, Harumi Sugimatsu, Masao Sakata, Rajendar Bahl, Masao Yanagisawa, "Classification of sperm whale clicks for real-time localization with triangulation", Abstracts of 17th Biennial Conference on the Biology of Marine Mammals, Cape Town, South Africa, Dec 2007, Poster presentation.

  37. Tomoki Inoue, Tamaki Ura, Harumi Sugimatsu, Junichi Kojima, Rajendar Bahl, S. Behera, Takashi Sakamaki, Hideyuki Takahashi, Muntaz Khan, S. Kar, C.S. Kar, B.K.Behera, "Long duration real-time acustic observation of Irrawaddy dolphins (Orcaella brevirostris) in Chilika Lagoon", Abstracts of 17th Biennial Conference on the Biology of Marine Mammals, Cape Town, South Africa, Dec 2007, Poster presentation.

  38. Rajendar Bahl, Harumi Sugimatsu, Junichi Kojima, Tamaki Ura, Sandeep Behera, Tomoki Inoue, Tetsuo Fukuchi, "Beam pattern estimation of clicks of a free-ranging Ganges river dolphin", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2007), Vancouver, Canada, September 29-October 04, 2007.

  39. T. Inoue, T. Ura, H. Sugimatsu, T. Sakamaki, J. Kojima, R. Bahl, S. Panda, M. Khan, B.K. Behera, S.K. Behera, H. Takahashi, S. Kar, C. Kar, "Long duration real-time observation of Irrawaddy dolphins in Chilika lagoon", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2007), Vancouver, Canada, September 29-October 04, 2007.

  40. Suleman Mazhar, Tamaki Ura, Rajendar Bahl, "Vocalization based Individual Classification of Humpback Whales using Support Vector Machine", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2007), Vancouver, Canada, September 29-October 04, 2007.

  41. S. Biradar, M. Agarwal, A. Kumar and R. Bahl, "Design of data packet for time delay and Doppler estimation for underwater acoustic communication", Intl. Symposium on Ocean Electronics (SYMPOL-2007), Kochi, Dec. 2007.

  42. Arnab Das, Arun Kumar and Rajendar Bahl, "Design of a comprehensive underwater target classifier for passive SONAR", Journal of Ship Technology, vol.3, no 1, pp.20-30, Jan. 2007.

  43. T. Ura, R. Bahl, H. Sugimatsu, J. Kojima, T. Inoue, T. Fukuchi, S. Behera, A. Pattnaik, M. Khan, S. Kar, C.S. Kar, D. Swain, "Estimating beam pattern and echolocation characteristics of clicks recorded from a free-ranging Ganges river dolphin", Proc. Of Intl Symp on Underwater Technology 2007, Tokyo, Japan, 17-20 April, 2007, pages 527-534.

  44. Arnab Das, Arun Kumar and Rajendar Bahl, "Performance analysis due to feature transformation for automated marine vessel recognition in cepstral domain", Proc. INDICON, New Delhi, 2006.

  45. Rajendar Bahl, Tamaki Ura, Tomoki Inoue, Harumi Sugimatsu, Takeshi Sakamaki, Junichi Kojima, Tomonari Akamatsu, Hideyuki Takahashi, Ajit Pattnaik, Muntaz Khan, Sandeep Behera, Sudhakar Kar, "Observation studies based on echolocation click signals of Irrawaddy dolphins in Chilika lagoon", J. Acoust. Soc. Am., Vol 120, No. 5, Pt. 2, page 3014, November 2006.

  46. Tamaki Ura, Harumi Sugimatsu, Tomoki Inoue, Rajendar Bahl, Junichi Kojima, Tomonari Akamatsu, Sandeep Behera, Ajit Pattnaik, Muntaz Khan, Sudhakar Kar, Chandra Sekhar Kar, Tetsuo Fukuchi, Hideyuki Takahashi, Debabrata Swain, "Estimates of bio-sonar characteristics of a free-ranging Ganges river dolphin", J. Acoust. Soc. Am., Vol 120, No. 5, Pt. 2, page 3228, November 2006.

  47. Arnab Das, Arun Kumar, R. Bahl, "Comprehensive Ocean Area Surveillance Technology (COAST)", Proc. Of Seminar on Offshore Security, Mumbai, India, June 2006, pages 22-24.

  48. Abhishek Singh, Arun Kumar, R. Bahl, "Hybrid detector for ship radiated signal in statistically varying underwater noise", Proc IEEE Intl Conf on Oceanic Engg (OCEANS ASIA-PACIFIC 2006), Singapore, 16-19 May 2006.

  49. Tamaki Ura, R. Bahl, M. Yano, T. Inoue, T. Sakamaki, T. Fukuchi, "Results from a high-resolution acoustic device for monitoring finless porpoises in coastal precincts off-Japan", Proc IEEE Intl Conf on Oceanic Engg (OCEANS ASIA-PACIFIC 2006), Singapore, 16-19 May 2006.

  50. Ryo Hirotsu, T. Ura, R. Bahl, M. Yanagisawa, "Analysis of sperm whale click by MUSIC algorithm", Proc IEEE Intl Conf on Oceanic Engg (OCEANS ASIA-PACIFIC 2006), Singapore, 16-19 May 2006.

  51. R. Bahl, T. Ura, H. Sugimatsu, T. Inoue, T. Sakamaki, J. Kojima, T. Akamatsu, H. Takahashi, S.K. Behera, A.K. Pattnaik, Muntaz Khan, S.K. Kar,"Acoustic survey of Irrawaddy dolphin populations in Chilika lagoon: first test of a compact high-resolution device", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2006 - Asia Pacific), Singapore, 16-19 May 2006.

  52. Review Report compiled by Rajendar Bahl, "Studies on passive observation of vocalizations of cetaceans conducted at Ura laboratory (1999-2005)", prepared for URA Laboratory, Underwater Technology Research Center, Institute of Industrial Science, The University of Tokyo, JAPAN, July 20, 2005, 70 pages.

  53. Tanmay Roy, Arun Kumar, Rajendar Bahl, "Estimation of a coupling feature for target classification using passive sonar", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2005), Washington DC, USA, September 18-23, 2005, pages 148-153.

  54. Arnab Das, A. Kumar, R. Bahl, "Study of feature discrimination effects due to time-varying channel for passive sonar", Proceedings of IEEE Intl Conf on Oceanic Engg (OCEANS 2005), Washington DC, USA, September 18-23, 2005, pages 1549-1556.

  55. Chr Rami Reddy, Abhishek Singh, Arun Kumar, M. Agarwal, R. Bahl, "Robust detection of ship radiated signal using a novel hybrid detector", Proc Natl Symposium on Ocean Electronics (SYMPOL-2005), Kochi, Dec 2005, pp 152-160.

  56. Arnab Das, Arun Kumar, R. Bahl, "Classification feature analysis in time-varying channel for passive sonar", Proc Natl Symposium on Ocean Electronics (SYMPOL-2005), Kochi, Dec 2005, pp 161-169.

  57. Tamaki Ura, Masato Yano, Rajendar Bahl, Tetsuo Fukuchi, Junichi Kojima, Takashi Sakamaki, "Performance of a compact high resolution acoustic survey device for monitoring group behaviour of small cetaceans", poster presented at the 16th Biennial Conference on the Biology of Marine Mammals, San Diego, CA, USA, December 12-16, 2005.

  58. R. Bahl, J. Luan, T. Ura, "Recognizing individual humpback whales from their songs", Advanced Underwater Technology for Bio-SONAR Study Workshop (ABIOS-2004), IIS University of Tokyo, March 16, 2004.

  59. Tamaki Ura, Rajendar Bahl, Masao Sakata, Junichi Kojima, Tetsuo Fukuchi, Junya Ura, Yoshiaki Nose, Harumi Sugimatsu, Kyoichi Mori, Takeshi Nakatani, Masao Yanagisawa, "Acoustic Tracking of Sperm Whales using Two Sets of Hydrophone Array", Proceedings of the 2004 International Symposium on Underwater Technology, Taipei, Taiwan, pages 103-107, April 20-23, 2004.

  60. Rajendar Bahl, Takeshi Nakatani, Tamaki Ura, Junichi Kojima, Tetsuo Fukuchi, Masao Sakata, Yoshiaki Nose, Junya Ura, Kyoichi Mori, Harumi Sugimatsu, Masao Yanagisawa, Hideyuki Suzuki, "Passive tracking of multiple diving sperm whales using single hydrophones at two mobile locations", J. Acoust. Soc. Am., Vol 115, No. 5, Pt. 2, page 2518, May 2004.

  61. T. Ura, R. Bahl, M. Sakata, J. Kojima, T. Fukuchi, J. Ura, K. Mori, T. Nakatani, Y. Nose, H. Sugimatsu, "Development of AUV-based system for acoustic tracking of diving sperm whales, Proceedings of OCEANS'04, Kobe Japan, pages 2302-2307, November 9-12, 2004.

  62. Rajendar Bahl, Takeshi Nakatani, Tamaki Ura, Masao Sakata, "Automatic classification of diving sperm whales by analysis of click time delay using two hydrophones", Proceedings of OCEANS'04, Kobe Japan, pages 2316-2320, November 9-12, 2004.

  63. R. Bahl, "A Bird's Eye View of Underwater Technology in India", presented at the 31st Underwater Technology Forum, University of Tokyo, April 21, 2003.

  64. R. Bahl and T. Ura, "Automatic Real-time Segregation and Classification of Multiple Vocalizing Sperm Whales", Seisan-Kenkyu Bimonthly Journal of IIS, University of Tokyo, Vol. 55, No. 3, May 2003, pages 61-64.

  65. Tanmay Roy, Arun Kumar, R. Bahl, "Passive range estimation using non-linear coupling characteristics", Proc. International Conference on Undersea Defense Technology, Sweden, June 2003.

  66. J. Luan, R. Bahl, T. Ura, T. Akamatsu, M. Yamaguchi, T. Sakamaki, K. Mori, "Model-Based Recognition of Individual Humpback Whales from their Vocalization Features", presented at Ocean Engineering Symposium, Tokyo, July 18, 2003.

  67. R. Bahl, T. Ura, T. Fukuchi, "Techniques for Segregation and Classification of Several Vocalizing Sperm Whales for AUV-based Localization Applications", Proceedings of OCEANS 2003, San Diego, USA, September 22-26, 2003, pages 457-463.

  68. R. Bahl, M.Yano, T. Ura, T. Akamatsu, D. Wang and K. Wang, "Single-Hydrophone Method for Reconstructing Dynamic Behavior of Endangered Chinese River Dolphin", Proceedings of OCEANS 2003, San Diego, USA, September 22-26, 2003, pages 473-477.

  69. R. Bahl, "Underwater Acoustics in India", (in Japanese), The Japan Workvessel Association magazine "Workvessel", No.270, November 2003, pages17-22.

  70. M. Yano, R. Bahl, T. Ura, T. Akamatsu, D. Wang, K. Wang, "High-Frequency Vocalization of Free-Ranging Baiji Reveals its Underwater Behavior In Situ", presented at the 15th Biennial Conference on the Biology of Marine Mammals, Greensboro, NC, USA, December 14-19, 2003.

  71. R. Bahl, T. Ura, J. Ura, Y. Nose, T. Fukuchi, J. Kojima, K. Mori, M. Sakata, H. Sugimatsu, Y. Shimizu, M. Yanagisawa, "Real-Time Classification and Tracking of Sperm Whales in a Multi-Whale Scenario", presented at the 15th Biennial Conference on the Biology of Marine Mammals, Greensboro, NC, USA, December 14-19, 2003.

  72. J. Luan, R. Bahl, T. Ura, T. Akamatsu, M. Yamaguchi, T. Sakamaki, K. Mori, "Results on Recognition of Individual Humpback Whales Based on Vocalization Models", presented at the 15th Biennial Conference on the Biology of Marine Mammals, Greensboro, NC, USA, December 14-19, 2003.

  73. R. Bahl, T. Ura and T. Fukuchi, "Towards identification of sperm whales from their vocalizations", Seisan-Kenkyu Bimonthly Journal of IIS, University of Tokyo, Vol. 54, No. 6, Nov. 2002, pages 51-55.

  74. B. Sundar Rajan, L. Venkata Subramaniam and R. Bahl, "Gilbert Varshamov Bound for Euclidean space codes over distance-uniform signal sets", IEEE Transactions on Information Theory, Volume 48(2), February 2002, pages 537-546.

  75. H. S. Chatha, A. Kumar and R. Bahl, "Simulation studies of underwater communication system, with error control coding and low probability of intercept features, in shallow oceanic channel", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 463-472, Dec. 2002.

  76. R. Dhiman, A. Kumar and R. Bahl, "Design of low power multi-DSP module for acoustic signal processing on remote platforms", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 361-370, Dec. 2002.

  77. R. K. Goswami, A. Kumar and R. Bahl, "Performance of a bispectrum based detector of quadratic phase coupled signals", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 343-350, Dec. 2002.

  78. M. A. K. Shetty, R. K. Nair, A. Kumar and R. Bahl, "Networking protocols for underwater local area networks", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 445-452, Dec. 2002.

  79. T. Roy, A. Kumar and R. Bahl, "A novel range estimation method for passive sonars", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 253-260, Dec. 2002.

  80. T. Roy, A. Kumar and R. Bahl, "Estimation of a non-linear coupling feature for underwater target classification in shallow water", Proc. Intl. Conf. on Sonar-Sensors and Systems, Kochi, pages 305-312, Dec. 2002.

  81. T. Roy, A. Kumar and R. Bahl, "Detection of quadratic phase coupling in shallow underwater channel", Proc. IEEE Intl. Conf. on Oceanic Engineering (OCEANS-2002), Biloxi, U.S.A., pages 2180-2186, Oct. 2002.

  82. H. S. Chatha, A. Kumar and R. Bahl, "Simulation studies of underwater communication system in shallow oceanic channel", Proc. IEEE Intl. Conf. on Oceanic Engineering (OCEANS-2002), Biloxi, U.S.A., pages 2401-2408, Oct. 2002.

  83. Tanmay Roy, Arun Kumar and R. Bahl, "Estimation of a non-linear coupling feature for underwater target classification", Proc. Intl. Conference on Undersea Defense Technology, La Spezia, Italy, June 2002.

  84. T. Roy, A. Kumar and R. Bahl, "A New Method for Estimating the Degree of Quadratic Phase Coupling", Undersea Defence Technology Conference, Hawaii, USA, 30 Oct-1 Nov 2001.

  85. Tanmay Roy, Arun Kumar and Rajendar Bahl, "Characterisation of Ship-Radiated Signals Using Higher Order Spectrum Analysis", Proc. of National Symposium on Ocean Electronics SYMPOL-2001 CUSAT, pages 89-99, Cochin, India, 18-19 Dec 2001.

  86. T. Roy, Arun Kumar, R. Bahl, "Acoustic Simulator for Ship Noise Propagation in Underwater Multipath Channel", MATLAB India Millennium Conference, Bangalore, India, Nov 2000.

  87. L. Venkata Subramaniam, B. Sundar Rajan and R. Bahl, "Performance of 4 and 8-state TCM Schemes with Asymmetric 8-PSK in Fading Channels", IEEE Trans on Vehicular Technology, Volume 49 (1), January 2000, Pages 211-219.