Technical Journals Publications

Sonwalkar, V. S., et al., “Dependence of multi-path propagation effects on UWB pulse characteristics: implications for communication and navigation”, 
2006 International Waveform Diversity & Design Conference, Lihue, HI, Jan 22 - 27, 2006.

Sonwalkar, V. S., et al., "UWB PULSE PROPAGATION OVER THE GROUND,” EMTS 2007, International Symposium on Electromagnetic Theory, 
URSI - Commission B, July 26 - 28, 2007, Ottawa, ON, Canada.

Venkatasubramanian, A., et al., "MEASUREMENTS AND SIMULATION OF UWB OVAL DIPOLE," EMTS 2007, International Symposium on 
Electromagnetic Theory, URSI - Commission B, July 26 - 28, 2007, Ottawa, ON, Canada.

Sonwalkar, V. S., The Influence of Plasma Density Irregularities on Whistler Mode Wave Propagation, Springer Lecture Notes in Physics,

and other inner magnetospheric regions by the RPI instrument on the IMAGE satellite, submitted, J. Geophys. Res., 108, A12, 1421, 2003.

Carpenter, D. L., M. A. Spasojevic, T. F. Bell, U. S. Inan, V. S. Sonwalkar, B. W. Reinisch, I. A. Galkin, R. F. Benson, J. L. Green, S. F. Fung, W. W. L. Taylor, and S. A. Boardsen, Radio sounding the Earth's plasmasphere and excitation of the whistler and Z modes by the Radio Plasma Imager (RPI) instrument on the IMAGE satellite, Proceedings of the Ionospheric Effects Symposium, Alexandria, VA, 2002.

Sonwalkar, V. S., X. Chen, J. Harikumar, D. L. Carpenter and T. F. Bell, Whistler-Mode Wave Injection Experiments in the Plasmasphere with a Radio Sounder, J. Atmos. Sol. Terr. Phys., 63, 1199-2116, 2001.

Sonwalkar, V. S. and Jayashree Harikumar, An Explanation of Ground Observations of Auroral Hiss: Role of Density Depletions and Meter-Scale Irregularities, J. Geophys. Res., 105, 18,86718,883, 2000.

Sonwalkar, V. S., Whistlers, Encyclopedia of Electrical and Electronic Engineering, J. G. Webster, Editor, Vol. 23, 580-591, Feb., 1999.

Sonwalkar, V.S., D.L Carpenter, R.A. Helliwell, M. Walt, U.S. Inan, D.L Caudle, and M. Ikeda, Properties of the magnetospheric hot plasma distribution deduced from whistler-mode wave injection at 2400 Hz; ground-based detection of azimuthal structure in magnetospheric hot plasmas, J. Geophys. Res. 102, 14,363-14380, 1997.

Carpenter, D. L., V. S. Sonwalkar, R.A. Helliwell, M. Walt, U.S. Inan, D.L Caudle, and M. Ikeda, Probing properties of the magnetospheric hot plasma distribution by whistler-mode wave injection multiple frequencies: Evidence of spatial as well as temporal growth, J. Geophys. Res. 102, 14,355-14362, 1997a.

Carpenter, D. L., M. Galland, T. F. Bell, V.S. Sonwalkar, U. S. Inan, J. LaBelle, A. J. Smith, T. D. G. Clark, and T. J. Rosenberg, Quasi-periodic ~ 5-60 s fluctuations of VLF signals propagating in the Earth-ionosphere waveguide; a result of pulsating aurora? J. Geophys. Res., 102, 347-361, 1997b.

Sonwalkar, V. S., A New ELF/VLF/LF Electromagnetic Wave Observatory in the Arctic: Applications to Space Weather and Auroral and Magnetospheric Physics, Proceedings of the United States - Japan workshop on Arctic Research, Geophysical Institute, University of Alaska, 153-58, 1996.

Sonwalkar, V. S., U. S. Inan, T. L. Aggson, W. M. Farrell, and R. Pfaff, Focusing of nonducted whistlers by the equatorial anomaly, J. Geophys. Res., 100, 7783-7790, 1995.

Sonwalkar, V. S. and D. L. Carpenter, On the diversity in the properties of radio bursts observed on the nightside of Venus, J. Atmos. Terr. Phys., 57, 557-573, 1995.

Sonwalkar, V. S., Magnetospheric LF-, VLF-, and ELF-waves, Chapter II/13, Handbook of Atmospheric Electrodynamics, 407-462, CRC Press, Inc., Boca Raton, Florida, April, 1995.

Sonwalkar, V. S., U. S. Inan, and T. F. Bell, An interpretation of a mysterious 3.4-4.6 kHz emission band observed on Voyager-2 near Neptune, J. Geophys. Res., 100, 1795-1809, 1995.

Sonwalkar, V. S., U. S. Inan, T. F. Bell, R. A. Helliwell, V. M. Chmyrev, Ya. P. Sobolev, O. Ya. Ovcharenko, and V. Selegej, Simultaneous observations of VLF ground transmitter signals on the DE 1 and COSMOS 1809 satellites: Detection of a magnetospheric caustic and a duct, J. Geophys. Res., 99, 17,511-17522, 1994.

Sonwalkar, V. S., U. S. Inan, T. F. Bell, R. A. Helliwell, O. A. Molchanov, J. L. Green, DE 1 VLF observations during Activny wave injection experiments, J. Geophys. Res., 99, 6173-6186, 1994.

Bell, T. F., U. S. Inan, D. Lauben, V. S. Sonwalkar, R. A. Helliwell, Ya. P. Sobolev, V. M. Chmyrev, S. Gonzalez, DE 1 and COSMOS 1809 observations of lower hybrid waves excited by VLF whistler mode waves, Geophys. Res. Lett., Vol. 21, No. 8, 653-656, 1994.

Henderson, T. R., V. S. Sonwalkar, R. A. Helliwell, U. S. Inan, and A. C. Fraser-Smith, A search for ELF/VLF emissions induced by earthquakes as observed in the ionosphere by the DE 2 satellite, J. Geophys. Res., 98, 9503-9514, 1993.

Draganov, A. B., U. S. Inan, V. S. Sonwalkar, and T. F. Bell, Whistlers and plasmaspheric hiss: Wave directions and three- dimensional propagation, J. Geophys. Res., 98, 11,401-11410, 1993.

Draganov, A. B., U. S. Inan, V. S. Sonwalkar, and T. F. Bell, Magnetospherically reflected whistlers as a source of plasmaspheric hiss, Geophys. Res. Lett., 19, 233-236, 1992.

Sonwalkar, V. S., D. L. Carpenter, and R. J. Strangeway, Testing radio bursts observed on the nightside of Venus for evidence of whistler mode propagation from lightning, J. Geophys. Res., 96, 17763-17778, 1991.

Bell, T. F., U. S. Inan, V. S. Sonwalkar, and R. A. Helliwell, DE-1 Observations of lower hybrid waves excited by VLF whistler mode waves, Geophys. Res. Lett., 18, 393-396, 1991.

Sonwalkar, V. S., R. A. Helliwell, and U. S. Inan, Wideband VLF electromagnetic bursts observed on the DE 1 satellite, Geophys. Res. Lett., 17, 1861-1864, 1990.

Sonwalkar, V. S., ``Lightning, Whistlers, and VLF Hiss: a Possible Relationship'', Physics of Space Plasmas, SPI Conference Proceedings and Reprint Series, Scientific Publishers, Inc., Cambridge, MA, 9, 477-482, 1989.

Sonwalkar, V. S. and U. S. Inan, Lightning as an embryonic source of plasmaspheric hiss, J. of Geophys. Res., 94, 6986-6994, 1989.

Sonwalkar, V. S. and U. S. Inan, Wave normal direction and spectral properties of whistler-mode hiss observed on the DE-1 satellite, J. of Geophys. Res., 93, 7493-7514, 1988.

Sonwalkar, V. S., and U. S. Inan, Measurement of Siple transmitter signal on the DE--1 satellite: wave normal direction and antenna effective length, J. of Geophys. Res., 1986, 91, 154-164, 1986.

Sonwalkar, V. S., New Signal Analysis Techniques and Their Applications to Space Physics, Ph.D. Thesis, Stanford University, 1986.

Sonwalkar, V. S., Analysis of ground transmitter signals received on a spacecraft, URSI meeting in Colorado, Jan., 13--17, 1986 (Awarded one of the URSI best student paper prize).

Sonwalkar, V. S., T. F. Bell, R. A. Helliwell, and U. S. Inan, Direct multiple path propagation: A fundamental property of nonducted VLF waves in the magnetosphere, J. of Geophys. Res., 89, 2823-2830, 1984.

Bell, T. F., J. P. Katsufrakis, V. S. Sonwalkar, R. A. Helliwell, Siple Station VLF wave-injection experiments: ISIS and ISEE satellite observations, Antarctic Journal, XIX, No 5, 230, 1984.

Tiwari, S., and V. S. Sonwalkar, A low noise, high gain, wide bandwidth amplifier, Electronic Engineering, 28, August 1977.

Tiwari, S., and V. S. Sonwalkar, Modified four phase stepper motor control, Electronic Engineering, 28, July 1977.

Tiwari, S., and V. S. Sonwalkar, A compact high voltage regulated power supply, Electronic Engineering, 34, June 1977.

Tiwari, S., and V. S. Sonwalkar, A fast low threshold pulse height discriminator, Electronic Engineering, 21, May 1977.

Tiwari, S., and V. S. Sonwalkar, Spectrally resolved photon counting system, B. Tech. Thesis, IIT, Kanpur, 1976.

Conference Papers and Published Abstracts

Sonwalkar, V. S., A. Venkatasubramanian, J. G. Hawkins, B. Satavalekar, B. Johnson, and C. E. Mayer, Dependance of multipath propagation effects on UWB pulse characteristics: implications for communication and navigation, 2006 International Waveform Diversity & Design Conference, January 22-27, 2006, Radisson Kauai Beach Resort 4331 Kauai Beach Drive, Lihue Hawaii, USA.

Venkatasubramanian, A., V.S. Sonwalkar, J.G. Hawkins, J. Li, Effect of UWB pulse shape on the performance of TH-BPPM receiver, 1st International Symposium on Wireless Pervasive Computing, 16 - 18 January 2006, Phuket, Thailand.

Sonwalkar V. S., R. Proddaturi, A. Venkatasubramanian, D. L. Carpenter, R. F. Benson, B. W. Reinisch, Remote Sensing of Electron Density and Density Irregularities from Whistler and Z-Mode Sounding Experiments by RPI on IMAGE, XXVIII General Assembly of International Union of Radio Science (URSI), 23-29 October 2005, New Delhi, India.

Sonwalkar, V.; Li, J.; Proddaturi, R.; Venkatasubramanian, A.; Carpenter, D.; Benson, R.; Reinisch, B. (2004), Interpretation of Vector Electric Field Measurements by RPI Using Three Dipole Antennas on IMAGE, Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract XXXXX-XX (http://127.0.0.1:6017/html/SM23A-0465.html ).

Li, J.; Sonwalkar, V.; Proddaturi, R..; Venkatasubramanian, A.; Carpenter, D.; Benson, R.; Reinisch, B. (2004), Remote Sensing of Magnetospheric Plasma Density from the Analysis of Discrete Whistler Mode Echoes Received by RPI on IMAGE, Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract XXXXX-XX (http://127.0.0.1:6017/html/SM22A-06.html ).


 Proddaturi, R.; Sonwalkar, V.; Li, J.; Venkatasubramanian, A.; Carpenter, D.; Benson, R.; Reinisch, B. (2004), Local Electron Density Measurements from Sounding Experiments by RPI on IMAGE, Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract XXXXX-XX ( http://127.0.0.1:6017/html/SM23A-0466.html ).

Sonwalkar, V., Role of plasma density structures (1 m--100 km scale) in the propagation of plasma waves in the magnetosphere, Workshop on High Frequency Waves in Geospace, 12-14 July, 2004, Ringberg Castle, Bavaria.

Sonwalkar, V.; Li, J.; Carpenter, D.; Venkatasubramanian, A.; Benson, R.; Reinisch, B., Whistler and Z mode radio sounding of the magnetosphere at altitudes < 5000 km by RPI on IMAGE, COSPAR 2004, 18-25 July 2004, Paris.

Sonwalkar, V. S., Electromagnetic emissions at high latitudes, The Aurora Borealis and Other Artic Phenomena, NSF CHAUTAUQUA COURSE (# 39)-2004, March 14-16, 2004, University of Alaska Fairbanks, Fairbanks, AK.

D. L. Carpenter, T. F. Bell, V. S. Sonwalkar, and B. W. Reinisch, The Whistler- and Z-Modes: New Tools For Radio Sounding of the Plasmasphere and Polar Regions from Middle to Low Altitudes, Presentation at the Yosemite Conference of Inner Magnetospheric Interactions, 3 - 6 February 2004, Yosemite, California, USA.


Sonwalkar et al., Remote Sensing of Magnetospheric Plasma Density from the Analysis of Whistler Mode Echoes Received by RPI on IMAGE, 2003 Fall Meeting, 8-12 December 2003, San Francisco, 2003.

J. Soboleff, L. Griffeth, V. Sonwalkar, J. and D. Dasher, Observations of Background Gamma Radiation in Alaska Using the ORION Network, 54TH ARCTIC SCIENCE CONFERENCE, Sept. 22-24, 2003, Fairbanks, Alaska.

Li, J., Sonwalkar, V. S., Carpenter, D. L., Venkatasubramanian, Remote Sensing of Magnetospheric Plasma Density from the Analysis of Whistler Mode Echoes Received by RPI on IMAGE, 54TH ARCTIC SCIENCE CONFERENCE, Sept. 22-24, 2003, Fairbanks, Alaska.

Venkatasubramanian, A., Sonwalkar, V. S., Li, J., Hawkins, J., Satavalekar, B., Numerical modeling of electromagnetic wave propagation in a hallway, 54TH ARCTIC SCIENCE CONFERENCE, Sept. 22-24, 2003, Fairbanks, Alaska.

Sonwalkar, V. S., Fish Assessment by Acoustics, Water resources technician training program for native Alaskans, School of Mineral Engineering, University of Alaska Fairbanks, July, 28 – Aug., 14, 2003.

Sonwalkar et al., Remote Sensing of Magnetospheric Plasma Density from the Analysis of Whistler Mode Echoes Received by RPI on IMAGE, USNC/CNC/URSI North American Radio Science Meeting, Columbus, Ohio, USA on June 22-27, 2003.

Chen, X., Sonwalkar, V. S., Observation and Analysis of Whistler Mode Echoes Received by RPI on IMAGE at High Latitudes, CEDAR 2003 18th summer workshop, June 15-20, Longmont, Colorado, 2003.

Sonwalkar, V. S., Introduction to Fisheries Acoustics, talk given to American Indian Science and Engineering Society, University of Alaska Fairbanks, 27 March, 2003

Sonwalkar, V. S., Electromagnetic emissions at high latitudes, The Aurora Borealis and Other Artic Phenomena During the Solar Maximum, NSF CHAUTAUQUA COURSE (# 33)-2003, March 19-21, 2003, University of Alaska Fairbanks, Fairbanks, AK

Sonwalkar, Vikas, Carpenter, Jayashree Harikumar, Rachel Huntzinger, Maria Spasojevic, Timothy Bell, Umran Inan, William Taylor, Bodo Reinisch, Observations and Analysis of Discrete and Diffuse Whistler Mode Echoes Received by RPI on IMAGE, Eos Trans. AGU, 83 (47), Fall Meet. Suppl., Abstract xxxxx-xx, 2002.

Sonwalkar, V. S., Z. Lai, B. L. Adams, J. J. Kelley, Numerical Simulations in Fisheries Acoustics: a New Approach to Estimate Uncertainties in Fish Counting Using Sonar, 53rd Arctic Science Conference, AAAS Arctic Division, University of Alaska Fairbanks, Fairbanks, 18-21 September 2002.

Sonwalkar, V. S., Fish assessment by acoustics, Water Resources Technician Training Program For Native Alaskans, School of Mineral Engineering, University of Alaska Fairbanks, September 9-26, 2002.

D. L. Carpenter, V.S. Sonwalkar, T. F. Bell, M. A. Spasojevic, U.S. Inan, R. F. Benson, B. W. Reinisch, Whistler and Z-mode echoes from radio sounding of the IMAGE satellite, Magnetospheric Imaging Workshop, Yosemite, California, 5 - 8 February 2002.

Sonwalkar, V. S., Electromagnetic emissions at high latitudes, The Aurora Borealis and Other Artic Phenomena During the Solar Maximum, 2002 Update SYUN AKASOFU, International Artic Research Center, JOHN KELLEY and VIKAS SONWALKAR, University of Alaska Fairbanks, GILBERT YANOW, NASA Jet Propulsion Laboratory, March 18-20, 2002, Fairbanks, AK

Sonwalkar, V. S. and J. Harikumar, Observations and Analysis of Diffuse Whistler Mode Echoes Received by RPI on Image, Eos Trans. AGU, 82(47), Fall Meet. Suppl., Abstract xxxxx-xx, 2001.

Harikumar, J. and V. S. Sonwalkar, Remote Sensing of the Auroral Magnetosphere From the Ground Observations of Impulsive Auroral Hiss, Eos Trans. AGU, 82(47), Fall Meet. Suppl., Abstract xxxxx-xx, 2001.

A. Orr, L. Griffeth, W. Splain, J. Kelley, V. Sonwalkar, S. Read and D. Dasher, NEWNET at the University of Alaska Fairbanks. Presented at the Sigma Xi national conference, November 2001.

Sonwalkar, V. S., Electromagnetic waves at high latitude, paper presented at NSF Chautauqua Course (#44), The Aurora Borealis and other Arctic Phenomena During Solar Maximum, IARC, UAF, Fairbanks, 10-15 March 2001.

Sonwalkar, V. S., X. Chen, J. Harikumar, D. L. Carpenter, M. Salvati, T. F. Bell, W. W. L. Taylor, S. F. Fung and J. L. Green, B. W. Reinisch, J. Goldstein and P. Reiff, Initial observations and analysis of whistler mode echoes received by RPI on IMAGE, EOS Transactions, 81, 48, 2000.

Bell, T. F., Carpenter, D. L., Sonwalkar, V. S., Reinisch, B. W., Salvati, M., Remote Diagnostics of the Ambient Cold Plasma Density in the Low Altitude Trough Region Using the Radio Plasma Imager on the IMAGE Spacecraft, EOS Transactions, 81, 48, 2000.

Sonwalkar, V. S., A direct and inverse model of fisheries acoustics, paper presented at Fisheries Acoustics workshop, 9-10 November 2000, IARC, UAF, Fairbanks.

Szuberla, C. and V. S. Sonwalkar, VLF data acquisition and analysis project, AURORA! Teacher Workshop, Sponsored by NASA and Alaska Space Grant Program, July 12-13, 2000, UAF, Fairbanks, Alaska.

Harikumar, J., Sonwalkar, V.S., 1999. On what we can Learn About Auroral Region From the Ground Observations of Auroral Hiss, EOS Transactions, 80, 46.

Sonwalkar, V.S., Chen, X., Harikumar, J., Carpenter, D.L., Bell, T.F., Salvati, M., Bortnik, J., 1999. Whistler Mode Wave Injection Experiments With RPI on IMAGE Spacecraft. EOS Transactions, 80, 46.

Levno-Chythlook F, Vago T, Orr A, Splain W, Kelley J, Andres RJ, Sonwalkar V, Dasher D, Read S, Sanders L (1999) Status of transboundary radiation monitoring in Alaska. Eos, Transactions 80:F113-F114.

Levno-Chythlook, F., T. Vago, A. Orr, W. Splain, J. Kelley, R. Andres, V. Sonwalkar, D. Dasher, S. Read, and L. Sanders, Status of Transboundary Radiation Monitoring in Alaska, Presented at the 50th AAAS-Arctic Science Conference, Denali National Park, 19-22 September 1999. The abstract is published in the Proceedings.

Sanders, L., C. Odom, J. J. Kelley, V. Sonwalkar, D. Dasher, S. Read, and W. Splain, Radiation Monitoring by Autonomous Stations in Alaska, presented at: The 4th International Conference on Environmental Radioactivity in the Arctic, Edinburgh, Scotland, 20-23 September 1999 (Abstract published in Proceedings)

Sanders, L., C. Odom, J. J. Kelley, V. Sonwalkar, D. Dasher, S. Read, and W. Splain, Radiation Monitoring by Autonomous Stations in Alaska, presented at: Autonomous Systems in Extreme Environments Workshop (NSF Sponsored), Jet Propulsion Laboratory, Pasadena, California August 31-September 2, 1999 (Abstract published in Proceedings).

Sonwalkar, V. S. and Barbara Adams, A Theoretical and Numerical Model of Fisheries Acoustics: Estimates of Uncertainties in Fish Counting in Rivers, presented at 2nd International Conference on Shallow Water Fisheries Sonar, 7-9 September 1999, Seattle, Washington, USA.

Adams, Barbara and Vikas Sonwalkar Analysis of Data Obtained from ADFG-July 1998 Sonar Experiment at Wood River, Dillingham, Alaska, presented at 2nd International Conference on Shallow Water Fisheries Sonar, 7-9 September 1999, Seattle, Washington, USA.

Pham, John and Vikas Sonwalkar Considerations in the choice of digital filters to identify and characterize single and multiple echoes returned by fish, presented at 2nd International Conference on Shallow Water Fisheries Sonar, 7-9 September, 1999.

Sonwalkar V. S., J. Harikumar, D. L. Carpenter, and T. F. Bell, Analysis of Whistler Mode Wave Injection Experiments with RPI on IMAGE Spacecraft, presented at XXVI URSI General Assembly, 13-21 Aug. 1999, Toronto Canada.

Sonwalkar V. S., and J. Harikumar, Scattering of Large Wave Normal Angle Whistler Mode Waves by Field-Aligned Density Irregularities in the Auroral Ionosphere: Applications to Continuous Auroral Hiss, presented at XXVI URSI General Assembly, 13-21 Aug. 1999, Toronto Canada.

Harikumar, J. and V. S. Sonwalkar, Trapping and Propagation of Large Wave Normal Angle Whistler Mode Waves Through Field-Aligned Density Depletions or Enhancements (Ducts) in the Auroral Magnetosphere: Applications to Impulsive Auroral Hiss, presented at XXVI URSI General Assembly, 13-21 Aug. 1999, Toronto Canada.

Sonwalkar, V. S., and Jayashree Harikumar, An Explanation of Ground Observations of Auroral Hiss: Role of Density Depletions and Meter-Scale Irregularities, paper presented at AGU 1998 Fall Conference in San Francisco, California, 6-10 December 1998.

Sonwalkar, V. S. and Jayashree Harikumar, Generation and Propagation of Auroral Hiss, paper presented at AGU 1997 Fall Conference in San Francisco, California, 8-12 December 1997.

Sonwalkar, V. S. and B. L. Adams, A Transmission-Line Model of Fisheries Acoustics: An Analysis of Fish Signature in the Sea-Bed Echo, presented at 1997 Arctic Science Conference, September 24-27, 1997, Valdez, Alaska.

Sonwalkar, V. S., L. Chang, K. Walworth, D. L. Carpenter, R. A. Helliwell, M. Walt, and U. S. Inan, Siple Station Wave Injection Experiments: Ground Based Remote Sensing of Magnetospheric Cold and Hot Plasma, paper presented at 1996 Fall meeting of the American Geophysical Union, 15-19 December, 1996, San Francisco, EOS, 77, 46, 595, 1996.

Sonwalkar, V. S., U. S. Inan, T. F. Bell, and D. L. Carpenter, Thunderstorm Coupling to the Magnetosphere: (1) Whistler-lightning correlations, (2) Contribution of lightning energy to the magnetosphere, (3) Lightning as a source of hiss, paper presented at the XXVth General Assemble of International Union of radio science, 28 Aug.- 5 Sept. 1996, Lille- France, H1-7, 444, 1996.

Sonwalkar, V. S., A New ELF/VLF/LF Electromagnetic Wave Observatory in the Arctic: Applications to Space Weather and Auroral and Magnetospheric Physics, United States - Japan workshop on Arctic Research, Geophysical Institute, University of Alaska, 1996.

Sonwalkar, V. S., L. Chang, K. Walworth, D. L. Carpenter, R. A. Helliwell, M. Walt, and U. S. Inan, `First Pulse Suppression' of Emission Activity, Presented at the 1995 AGU Fall Conference at San Francisco, 11-15, EOS Transactions, 76, 46 Dec. 1995.

Sonwalkar, V. S., U. S. Inan, and T. F. Bell, An interpretation of a mysterious 3.4-4.6 kHz emission band observed on Voyager-2 near Neptune, AGU fall meeting in San Francisco, EOS, 75, supplement, 541, 1994.

Ikeda, M., V. S. Sonwalkar, D. L. Carpenter, R. A. Helliwell, and U. S. Inan, Siple Station wave injection experiments: frequency dependence of wave-particle interaction parameters, AGU fall meeting in San Francisco, EOS, 75, supplement, 501, 1994.


Hakeman, D. J., U. S. Inan, V. S. Sonwalkar, and S. C. Reising, Long range thunderstorm location using a broadband VLF spheric detection technique, AGU fall meeting in San Francisco, EOS, 74, supplement, 165, 1993.

Sonwalkar, V. S. and U. S. Inan, Focusing of nonducted whistlers by equatorial anomaly, AGU fall meeting in San Francisco, EOS, 74, supplement, 499, 1993.

Sonwalkar, V. S. and U. S. Inan, Wideband Data Analysis and Archiving, Community-wide Workshop on NASA's Space Physics Data System, Rice University, Houston, Texas, June, 1-3, 1993.

Caudle, D. L., V. S. Sonwalkar, D. L. Carpenter, R. A. Helliwell, and U. S. Inan, Siple Station wave injection experiments: potential for hot plasma diagnostics, AGU fall meeting in San Francisco, EOS, 73, supplement, 453, 1992.

Sonwalkar, V. S. and U. S. Inan, Thunderstorm coupling to the magnetosphere, AGU fall meeting in San Francisco, EOS, 73, supplement, 415, 1992.

Draganov, A. B., U. S. Inan, V. S. Sonwalkar, and T. F. Bell, Three-dimensional whistler wave propagation and implications for plasmaspheric hiss, AGU fall meeting in San Francisco, EOS, 73, supplement, 453, 1992.

Aggson, T. L., J. DeConde, W. M. Farrell, M. D. Sesch, R. Pfaff, U. S. Inan, and V. S. Sonwalkar, Observations of spheric-like noise at satellite altitudes near the magnetic dip equator, AGU fall meeting in San Francisco, EOS, 73, supplement, 415, 1992.

Sonwalkar, V. S., Testing radio bursts observed on the nightside of Venus for evidence of whistler mode propagation from lightning, AGU spring meeting in Baltimore, EOS, 72, supplement, 172, 1991.

Henderson, T., V. S. Sonwalkar, R. A. Helliwell, U. S. Inan, and A. C. Fraser-Smith, A search for ELF/VLF emissions induced by earthquakes as observed in the ionosphere by the DE 2 satellite, AGU fall meeting in San Francisco, EOS, 72, supplement, 330, 1991.

Sonwalkar, V. S. and R. A. Helliwell, Observations of impulsive VLF emissions in the subauroral region, AGU fall meeting in San Francisco, EOS, 72, supplement, 398, 1991.

Sonwalkar, V. S., D. L. Carpenter, and R. J. Strangeway, On the question of lightning on Venus, AGU fall meeting in San Francisco, EOS, 71, supplement, 1431, 1990.

Chmyrev, V. M., Ya. P. Sobolev, O. Ya. Ovcharenko, V. Selegej, V. S. Sonwalkar, U. S. Inan, T. F. Bell, R. A. Helliwell, and M. Hayakawa, Simultaneous observations on DE 1 and Cosmos 1809 of 15 kHz signals from a ground based VLF transmitter, AGU fall meeting in San Francisco, EOS, 71, supplement, 1535, 1990.

Bell, T. F. U. S. Inan, V. S. Sonwalkar, R. A. Helliwell, and V. M. Chmyrev, DE 1 and COSMOS-1809 satellite observations of lower hybrid waves excited by VLF whistler mode waves, AGU fall meeting in San Francisco, EOS, 71, supplement, 1535, 1990.

Sonwalkar, V. S., U. S. Inan, and T. F. Bell, 3-D ray tracing simulations of VLF waves excited by a source in the magnetosphere, URSI meeting in Colorado, Jan., 3--5, 1990.

Sonwalkar, V. S., Helliwell, R. A., and U. S. Inan, Impulsive VLF waves observed on the DE 1 satellite, URSI meeting in Colorado, Jan., 3--5, 1990.

Sonwalkar, V. S. and U. S. Inan, Association of magnetospheric whistler with localized lightning discharges, AGU fall meeting in San Francisco, EOS, 70, supplement, 1009, 1989.

Helliwell, R. A., V. S. Sonwalkar, and U. S. Inan, Impulsive VLF waves observed on the DE 1 satellite, AGU fall meeting in San Francisco, EOS, 70, supplement, 1271, 1989.

Carpenter, D. L., V. S. Sonwalkar, and T. F. Bell, On the interpretation of signals detected in the nighttime ionosphere of Venus, IAGA 1989 Assembly, the University of Exeter, UK., July 26-27, 1989.

Sonwalkar, V. S., Whistlers and hiss observed on DE 1 satellite, International Workshop on A New Antarctic ELF/VLF Wave-Injection Facility, at Stanford University, USA., April 24-28, 1989.

Sonwalkar, V. S., Lightning, Whistlers, and VLF Hiss: a Possible Relationship, 1989 Cambridge Workshop in Theoretical Geoplasma Physics, MIT, Cambridge, MA, June 12-16, 1989.

Sonwalkar, V. S. and U. S. Inan, Lightning as an embryonic source of plasmaspheric hiss, AGU fall meeting in San Francisco, EOS, 69, supplement, 1385, 1988.

Sonwalkar, V. S., T. F. Bell, R. A. Helliwell, and U. S. Inan, A method to measure anisotropic properties of a receiving dipole antenna in a magnetoplasma, AGU meeting in San Francisco, EOS, 68, supplement, 1437, 1987.

Sonwalkar, V. S., and U. S. Inan, Wave normal direction and spectral properties of whistler mode hiss observed on DE 1 satellite, XXII General Assembly of URSI, Tel Aviv, Israel, Aug. 24 - Sept. 2, 1987.

Sonwalkar, V. S., and U. S. Inan, Wave normal direction and spectral properties of whistler mode hiss observed on DE 1 satellite, AGU spring meeting in Baltimore, May, 1987.

Sonwalkar, V. S., and U. S. Inan, Analysis of whistler mode hiss observed on DE 1 satellite, AGU fall meeting in San Francisco, EOS, 67, supplement, 1186, 1986.

Sonwalkar, V. S., and U. S. Inan, Wave normal direction and polarization of whistler mode hiss observed on DE 1 satellite, AGU meeting in Baltimore, EOS, 67, supplement, 350, 1986.

Sonwalkar, V. S., Analysis of ground transmitter signals received on a spacecraft, URSI meeting in Colorado, Jan., 13--17, 1986.

Sonwalkar, V. S., and U. S. Inan, Wave normal direction of whistler--mode signals observed on DE--1 satellite, AGU fall meeting in San Francisco, EOS, 66, supplement, 1035, 1985.

Sonwalkar, V. S., and U. S. Inan, Measurement of whistler mode waves observed on a spinning satellite: Effective length of an electric dipole, AGU spring meeting in Baltimore, EOS, 66, supplement, 349, 1985.

Sonwalkar, V. S., and L. R. O. Storey, Kinetic and kinematic constraints in the measurement of electromagnetic fields on a spacecraft, AGU fall meeting in San Francisco, EOS, 65, supplement, 1052, 1984.

Sonwalkar, V. S., T. F. Bell, R. A. Helliwell, and U. S. Inan, Direct multiple path magnetospheric propagation: A fundamental property of the VLF signals transmitted from Siple station, Antarctica, AGU fall meeting in San Francisco, EOS, 63, supplement, 1064, 1982

Bernhardt P. A., V. S. Sonwalkar, D. L. Carpenter, C. G. Park, R. A. Helliwell, VLF beacon transmission from the space shuttle, National Radio Science Meeting, Boulder, Colorado, November 6--9, 1978.

Reports

Vikas Sonwalkar, Arun Venkatasubramanian, Joseph G. Hawkins, Jingbo Li,Bipin Satavalekar, Bruce Johnson Analytical Models and Simulations of Ultra Wideband Communication Systems, Subcontractor Report, Prime Contract N00164-05-D-6653, Submitted to Kachemak Research Development Inc., August 10, 2005.

J. Hawkins, B. Johnson, C. Mayer, V. Sonwalkar, A. Venkatasubramanian, Anechoic Chamber and Instrumentation Calibration Results, Prime Contract N00164-05-D-6653, Submitted to Kachemak Research Development Inc., August 10, 2005.

J. Hawkins, V. Sonwalkar, B. Satavalekar, B. Johnson, J. Li, A. Venkatasubramanian, Measurement and Modeling of Ultra Wideband Communication and Positioning Systems, Subcontractor Report, Work Directive No. KRD-003, Section 3, U.S. Army TARDEC, October 21, 2004b.

J. Hawkins, V. Sonwalkar, B. Satavalekar, B. Johnson, J. Li, A. Venkatasubramanian, Measurement and Modeling of Ultra Wideband Communication and Positioning Systems and Testing and Modification of the ODIS Wireless Video Relay System, Subcontractor Report, Work Directive No. KRD-003, Section 2, U.S. Army TARDEC, March 18, 2004a.

J. Hawkins, V. Sonwalkar, B. Satavalekar, B. Johnson, A. Venkatasubramanian, Diagnostic Testing of the ODIS Communication System, Subcontractor Report, Work Directive No. KRD-003, Section 1, U.S. Army TARDEC, September 30, 2003.

V. Sonwalkar and N. Avdonina, Numerical Modeling and Simulations to Investigate the Potential of Spintronics Devices for Applications in Computer and Information Technology, DMEA Progress Report, December 2003

J. Hawkins, V. Sonwalkar, B. Satavalekar, B. Johnson, A. Venkatasubramanian, Diagnostic Testing of the ODIS Communication System, Subcontractor Report, Work Directive No. KRD-003, Section 1, U.S. Army TARDEC, September 30, 2003.

Sonwalkar, V. S., Modeling of Riverine Fisheries Acoustics: New Methods to Estimate Fish Abundance, Composition, and Uncertainties in Data Analysis, Final Report, refereed report submitted to Alaska Science and Technology Foundation, April 2003.

Sonwalkar, Vikas S., Barbara L. Adams, Mark L. Ayers, Biao Chen, Zhiguo Lai, and Hoang X. Pham, Numerical simulations in fisheries acoustics, Internal Report, Institute of Northern Engineering, University of Alaska Fairbanks, INER03.02, 2002.

Modeling of Riverine Fisheries Acoustics: New Methods to Estimate Fish Abundance, Composition, and Uncertainties in Data Analysis, refereed report submitted to Alaska Science and Technology Foundation, May 2000.

Modeling of Riverine Fisheries Acoustics: New Methods to Estimate Fish Abundance, Composition, and Uncertainties in Data Analysis, refereed report submitted to Alaska Science and Technology Foundation, May 1999.

An Analysis of Sonar Data Obtained at Wood River (July 1998) Using BioSonics 418 kHz Split-beam Sonar System: (a) Analysis of Raw Data and (b) Analysis of Vtrack Algorithm, refereed report submitted to Alaska Department of Fish and Game, May 1999.

Report of the Community-Wide Workshop on NASA's Space Physics Data System, Rice University, Houston, June, 1993.

Report on satellite and ground observations during Activny sessions, STAR laboratory, Stanford, May 1990.

Report on the International Antarctic ELF/VLF wave-injection facility workshop, Stanford University, April, 1989.

Report on the feasibility study of the VLF beacon transmission from the space shuttle, Radioscience Laboratory, Stanford, October 1978.