|
Darrell Jackson Principal Engineer Emeritus; Research Professor Emeritus, Electrical Engineering drj@apl.washington.edu Phone 206-543-1359 |
Biosketch
Darrell Jackson is engaged in theoretical and experimental research in ocean acoustics. This includes random scattering in the ocean, acoustic remote sensing of the ocean bottom, and related signal processing methods.
Education
B.S. Electrical Engineering, University of Washington, 1960
M.S. Electrical Engineering, University of Washington, 1963
Ph.D. Electrical Engineering, University of Washington, 1966
Ph.D. Physics, California Institute of Technology, 1977
Projects
 |
Acoustic Remote Sensing of Hydrothermal Flow High-frequency acoustic remote sensing offers an attractive method of detecting and probing scales of hydrothermal flow that are unattainable by point sampling methods. Two new methods are: 1) scintillation thermography to detect and characterize diffuse flow fields; and 2) plume particulate scattering to estimate flow velocity and particulate concentrations in the high temperature vent plumes. |
|
 |
|
Publications |
2000-present and while at APL-UW |
|
Mid-frequency geoacoustic inversion using bottom loss data from the Shallow Water 2006 Experiment Yang, J., D.R. Jackson, and D. Tang, "Mid-frequency geoacoustic inversion using bottom loss data from the Shallow Water 2006 Experiment," J. Acoust. Soc. Am., 129, 2426, doi:10.1121/1.3587932, 2011. |
More Info |
1 Apr 2011
|
|
|||||
|
Geoacoustic inversion work has typically been carried out at frequencies below 1 kHz, assuming flat, horizontally stratified bottom models. Despite the relevance to Navy sonar systems, many of which operate at mid-frequencies (1-10 kHz), limited inversion work has been carried out in this frequency band. This paper is an effort to demonstrate the viability of geoacoustic inversion using bottom loss data in the frequency band of 2-5 kHz. The acoustic measurements were taken during the Shallow Water 2006 Experiment off the coast of New Jersey. A half-space bottom model, with three parameters, density, compressional wave speed, and attenuation, was used for geoacoustic inversion by fitting the model to data in the least-squares sense. Inverted sediment sound speed was compared with direct measurements and inversion results using different techniques in the same area. The comparison shows that bottom loss can be used to infer sediment geoacoustic parameters at mid-frequencies. In addition, observations and modeling results demonstrate that forward scattering from topographical changes is important at mid-frequencies and should be taken into account in sound propagation predictions and geoacoustic inversion. To cope with fine-scale topographic variability, measurement technique such as averaging over tracks may be necessary. |
|||||||||
|
Multibeam sonar observations of hydrothermal flows at the Main Endeavour Field Rona, P.A., K.G. Benis, C.D. Jones, and D.R. Jackson, "Multibeam sonar observations of hydrothermal flows at the Main Endeavour Field," J. Acoust. Soc. Am., 129, 2373, doi:10.1121/1.3587686, 2011. |
More Info |
1 Apr 2011
|
|
|||||
|
The Cabled Observatory Vent Imaging Sonar has been deployed at the Main Endeavour Node of the Canadian Neptune cabled observatory and has acquired data on plume and diffuse hydrothermal flows. Based on the Reson 7125 multibeam sonar and operating at 200 and 400 kHz, two-dimensional and three-dimensional time series are produced using plume backscattering, Doppler shift, and acoustic scintillation. Hydrothermal plumes and diffuse flow are important as agents of transfer of heat, chemicals, and biological material from the mantle and crust into the ocean in quantitatively significant amounts. High-frequency sonar measurements offer the possibility of inversion to obtain fluxes of central importance in these processes. Long-term time series, obtainable in cabled systems, allow observations of hydrothermal response to tidal, tectonic, and volcanic forcing. Examples will be given of plume bending due to currents, determination of entrainment of ambient water, time variation of diffuse flows, and Doppler determination of volume flux. |
|||||||||
|
Simplified formulations for sea-surface scattering for use in modeling equalizer performance in underwater communications Rouseff, D. and D.R. Jackson, "Simplified formulations for sea-surface scattering for use in modeling equalizer performance in underwater communications," J. Acoust. Soc. Am., 129, 2665, doi:10.1121/1.3588917, 2011. |
More Info |
1 Apr 2011
|
|
|||||
|
Reflection off the rough sea surface typically introduces time spread in an acoustic signal. The details of channel response and hence the time spread will change as the sea surface evolves. Communications signals that are spread by the rough surface may still be recompressed and demodulated successfully by an equalizer providing that the channel response does not change too rapidly. To aid in designing an equalizer, it would be useful to know which acoustic paths should be treated as useful signal and which must be treated as noise because they change too rapidly. Viewed as a rough surface scattering problem, the classic Kirchhoff approximation should be appropriate for modeling reflected communications signals. Textbook descriptions of the Kirchhoff approximation are not promising, however, as they imply that the calculations depend on the details of the surface wave spectrum. In the present work, simplified expressions for the surface reflected communications signals are derived. The simplified results are tested in two ways: Predictions for the mutual coherence function are compared to numerically intense calculations, and predictions for communications performance are compared to experimental results. |
|||||||||
|
Wave scattering and interaction in elastic sea beds Ivakin, A.N., and D.R. Jackson, "Wave scattering and interaction in elastic sea beds," J. Acoust. Soc. Am., 129, 2426, doi:10.1121/1.3587935, 2011. |
More Info |
1 Apr 2011
|
|
|||||
|
A first-order perturbation model of scattering in an elastic medium is revisited and discussed. The material properties of the medium are defined by three spatially fluctuating variables, the density and two Lame parameters. The wave interaction process is described in terms of four mechanisms of scattering and energy conversion: two without change of the wave type, from compressional to compressional and from shear to shear, and two with the type conversion, from compressional to shear and vice versa. The model is applied to the case of acoustic scattering from and propagation in underwater sediments of different types, sand and rock. Wave interaction and attenuation due to various mechanisms of scattering in the sediment are considered. An improved method for calculation of the seabed scattering strength is proposed, which takes into account the so-called "windowing" effect. It allows more accurate accounting for the contribution of volume heterogeneities near the sediment surface and its comparison with the first-order roughness mechanism of scattering. The frequency-angular dependencies of the scattering strength for elastic sandy and rocky seafloors are calculated, and behaviors of the volume and roughness contributions are compared. |
|||||||||
|
A geoacoustic bottom interaction model (GABIM) Jackson, D.R., R.I. Odom, M.L. Boyd, and A.N. Ivakin, "A geoacoustic bottom interaction model (GABIM)," IEEE J. Ocean. Eng., 35, 603-617, 2010. |
More Info |
29 Jul 2010
|
|
|||||
|
The geoacoustic bottom interaction model (GABIM) has been developed for application over the low-frequency and midfrequency range (100 Hz to 10 kHz). It yields values for bottom backscattering strength and bottom loss for stratified seafloors. The model input parameters are first defined, after which the zeroth-order, nonrandom problem is discussed. Standard codes are used to obtain bottom loss, uncorrected for scattering, and as the first step in computation of scattering. The kernel for interface scattering employs a combination of the Kirchhoff approximation, first-order perturbation theory, and an empirical expression for very rough seafloors. The kernel for sediment volume scattering can be chosen as empirical or physical, the latter based on first-order perturbation theory. Examples are provided to illustrate the various scattering kernels and to show the behavior predicted by the full model for layered seafloors. Suggestions are made for improvements and generalizations of the model. |
|||||||||
|
Fine-scale volume heterogeneity in a mixed sand/mud sediment off Fort Walton Beach, FL Briggs, K.B., A.H. Reed, D.R. Jackson, and D. Tang, "Fine-scale volume heterogeneity in a mixed sand/mud sediment off Fort Walton Beach, FL," IEEE J. Ocean. Eng., 35, 471-487, 2010. |
More Info |
26 Jul 2010
|
|
|||||
|
As part of the effort to characterize the acoustic and physical properties of the seafloor during the high-frequency 2004 Sediment Acoustics Experiment (SAX04), fine-scale variability of sediment sound speed and density was measured in a medium quartz sand using diver cores and an in situ conductivity probe. This study has a goal of providing environmental input to high-frequency backscatter modeling efforts. Because the experiment was conducted immediately following exposure of the site to Hurricane Ivan, measurements revealed storm-generated sedimentary structure that included mud deposits and trapped sand pockets suspended in the mud. |
|||||||||
|
Dispersion and attenuation due to scattering from heterogeneities of the frame bulk modulus of a poroelastic medium Hefner, B.T., and D.R. Jackson, "Dispersion and attenuation due to scattering from heterogeneities of the frame bulk modulus of a poroelastic medium," J. Acoust. Soc. Am., 127, 3372-3384, 2010. |
More Info |
1 Jun 2010
|
|
|||||
|
While Biot theory can successfully account for the dispersion observed in sand sediments, the attenuation at high frequencies has been observed to increase more rapidly than Biot theory would predict. In an effort to account for this additional loss, perturbation theory is applied to Biot's poroelastic equations to model the loss due to the scattering of energy from heterogeneities in the sediment. A general theory for propagation loss is developed and applied to a medium with a randomly varying frame bulk modulus. The theory predicts that these heterogeneities produce an overall softening of the medium as well as scattering of energy from the mean fast compressional wave into incoherent fast and slow compressional waves. This theory is applied to two poroelastic media: a weakly consolidated sand sediment and a consolidated sintered glass bead pack. The random variations in the frame modulus do not have significant effects on the propagation through the sand sediment but do play an important role in the propagation through the consolidated medium. |
|||||||||
|
Mid- to high-frequency acoustic penetration and propagation measurements in a sandy sediment Hefner, B.T., D.R. Jackson, K.L. Williams, and E.I. Thorsos, "Mid- to high-frequency acoustic penetration and propagation measurements in a sandy sediment," IEEE J. Ocean. Eng., 34, 372-387, 2009. |
30 Oct 2009
|
|
|
Scattering by sinusoidal pressure-release surfaces Jackson, D.R., "Scattering by sinusoidal pressure-release surfaces," J. Acoust. Soc. Am., 126, 2166, 2009. |
1 Oct 2009
|
|
|
The role of porosity fluctuations in scattering from sand sediments and in propagation losses within the sediment Hefner, B.T., and D.R. Jackson, "The role of porosity fluctuations in scattering from sand sediments and in propagation losses within the sediment," J. Acoust. Soc. Am., 126, 2168, 2009. |
1 Oct 2009
|
|
|
Acoustic observation of the time dependence of the roughness of sandy seafloors Jackson, D.R., M.D. Richardson, K.L. Williams, A.P. Lyons, C.D. Jones, K.B. Briggs, and D. Tang, "Acoustic observation of the time dependence of the roughness of sandy seafloors," IEEE J. Ocean. Eng., 34, 407-422, 2009. |
28 Aug 2009
|
|
|
Acoustic backscattering from a sand and a sand/mud environment: Experiments and data/model comparisons Williams, K.L., D.R. Jackson, D. Tang, K.B. Briggs, and E.I. Thorsos, "Acoustic backscattering from a sand and a sand/mud environment: Experiments and data/model comparisons," IEEE J. Ocean. Eng., 34, 388-398, 2009. |
4 Aug 2009
|
|
|
Measurement and modeling of broadband Bragg scattering from a sinusoidal surface Tang, D., and D.R. Jackson, "Measurement and modeling of broadband Bragg scattering from a sinusoidal surface," J. Acoust. Soc. Am., 125, 2661, 2009. |
1 Apr 2009
|
|
|
Midfrequency backscatter imaging of fish schools in a shallow water waveguide Jones, C.D., and D.R. Jackson, "Midfrequency backscatter imaging of fish schools in a shallow water waveguide," J. Acoust. Soc. Am., 125, 2550, 2009. |
1 Apr 2009
|
|
|
The effects of scattering from heterogeneities in porosity during sound propagation through sand sediments Hefner, B.T., D.R. Jackson, and J. Calantoni, "The effects of scattering from heterogeneities in porosity during sound propagation through sand sediments," J. Acoust. Soc. Am., 125, 2746, 2009. |
1 Apr 2009
|
|
|
Dispersion and attenuation due to scattering from heterogeneities in the frame bulk and shear moduli of sand sediments Hefner, B.T., D.R. Jackson, and J. Calantoni, "Dispersion and attenuation due to scattering from heterogeneities in the frame bulk and shear moduli of sand sediments," J. Acoust. Soc. Am., 123, 3441, 2008 |
1 May 2008
|
|
|
Synthetic aperture sonar imaging of simple finite targets near a sediment-water interface Kargl, St., K.L. Williams, E. Thorsos, D.R. Jackson, and D. Tang, "Synthetic aperture sonar imaging of simple finite targets near a sediment-water interface," J. Acoust. Soc. Am., 123, 3944, 2008. |
1 May 2008
|
|
|
High-Frequency Seafloor Acoustics Jackson, D.R., and M.D. Richardson, "High-Frequency Seafloor Acoustics," New York, Springer, 616 pp., 2007. (See Dr. Jacksons page under PEOPLE to find errata for High-Frequency Seafloor Acoustics.) |
30 Jan 2007
|
|
|
Overview of SAX99 and SAX04 measurements of sediment sound speed and attenuation Thorsos, E.I., K.L. Williams, D.R. Jackson, and D. Tang, "Overview of SAX99 and SAX04 measurements of sediment sound speed and attenuation," J. Acoust. Soc. Am., 117, 2494, 2005. |
1 Aug 2005
|
|
|
A method for Doppler acoustic measurement of black smoker flow fields Jackson, D.R., C.D. Jones, P.A. Rona, and K.G Bemis, "A method for Doppler acoustic measurement of black smoker flow fields," Geochem. Geophys., Geosyst., 4, 10.1029/2003GC000509, 2003. |
14 Nov 2003
|
|
|
Acoustic backscattering experiments in a well characterized sand sediment: Data/model comparisons using sediment fluid and Biot models Williams, K.L., D.R. Jackson, E.I. Thorsos, D. Tang, and K.B. Briggs, "Acoustic backscattering experiments in a well characterized sand sediment: Data/model comparisons using sediment fluid and Biot models," IEEE J. Ocean. Eng., 27, 376-387, DOI: 10.1109/JOE.2002.1040925, 2002. |
1 Jul 2002
|
|
|
Comparison of sound speed and attenuation measured in a sandy sediment to predictions based on the Biot theory of porous media Williams, K.L., D.R. Jackson, E.I. Thorsos, and D. Tang, Schock, S.G., "Comparison of sound speed and attenuation measured in a sandy sediment to predictions based on the Biot theory of porous media," IEEE J. Ocean. Eng., 27, 413-428, DOI: 10.1109/JOE.2002.1040928, 2002. |
1 Jul 2002
|
|
|
Fine-scale volume heterogeneity measurements in sand Tang, D., K.B. Briggs, K.L. Williams, D.R. Jackson, E.I. Thorsos, and D.B. Percival, "Fine-scale volume heterogeneity measurements in sand," IEEE J. Ocean. Eng., 27, 546-560, DOI: 10.1109/JOE.2002.1040937, 2002. |
1 Jul 2002
|
|
|
High-frequency subcritical acoustic penetration into a sandy sediment Jackson, D.R., K.L. Williams, E.I. Thorsos, and S.G. Kargl, "High-frequency subcritical acoustic penetration into a sandy sediment," IEEE J. Ocean. Eng., 27, 346-361, doi:10.1109/JOE.2002.1040923, 2002. |
1 Jul 2002
|
|
|
Ocean acoustics, matched-field processing and phase conjugation Kuperman, W.A., and D.R. Jackson, "Ocean acoustics, matched-field processing and phase conjugation," in Imaging of Complex Media with Acoustic and Seismic Waves, edited by Fink et al., 43-96 (Spinger-Verlag, Berlin, 2002). |
15 Jan 2002
|
|
|
Decision-directed passive phase conjugation: Equalisation performance in shallow water Flynn, J.A., J.A. Ritcey, W.L.J. Fox, D.R. Jackson, and D. Rouseff, "Decision-directed passive phase conjugation: Equalisation performance in shallow water," Electronics Lett., 37(25), 1551-1553, 2001. |
6 Dec 2001
|
|
|
Underwater acoustic communication using passive phase conjugation Rouseff, D., W.L.J. Fox, D.R. Jackson, and C.D. Jones, "Underwater acoustic communication using passive phase conjugation," MTS/IEEE Oceans 2001, 5-8 November, Honolulu, HI, doi:10.1109/OCEANS.2001.968344 (IEEE, 2001). |
5 Nov 2001
|
|
|
Decision-directed passive phase conjugation for underwater acoustic communications with results from a shallow-water trial Flynn, J.A., J.A. Ritcey, W.L.J. Fox, D.R. Jackson, and D. Rouseff, "Decision-directed passive phase conjugation for underwater acoustic communications with results from a shallow-water trial," Conf. Record of the 35th Asilomar Conference on Signals, Systems, and Computers, 4-7 November 2001, edited by M.B. Matthews, 1420-1427, doi:10.1109/ACSSC.2001.987724 (IEEE, 2001). |
4 Nov 2001
|
|
|
Passive phase conjugation for underwater communication Rouseff, D., W.L.J. Fox, and D.R. Jackson, "Passive phase conjugation for underwater communication," J. Acoust. Soc. Am., 110, 2632, 2001. |
1 Nov 2001
|
|
|
Underwater acoustic communication by passive phase conjugation: Theory and experimental results Rouseff, D., D.R. Jackson, W.L.J. Fox, C.D. Jones, J.A. Ritcey, and D.R. Dowling, "Underwater acoustic communication by passive phase conjugation: Theory and experimental results," IEEE J. Ocean. Eng., 26(4), 821-831, 2001. |
1 Oct 2001
|
|
|
An overview of SAX99: Acoustic Measurements Thorsos, E.I., K.L. Williams, N.P. Chotrios, J.T. Christoff, K.W. Commander, C.F. Greenlaw, D.V. Holliday, D.R. Jackson, J.L. Lopes, D.E. McGehee, J.E. Piper, M.D. Richardson, and D. Tang, "An overview of SAX99: Acoustic Measurements," IEEE J. Ocean. Eng., 26, 4-25, 2001. |
1 Jan 2001
|
|
|
Acoustic penetration at subcritical grazing angles: Measurements and comparison with simulations based on perturbation theory Jackson, D.R., K.L. Williams, D. Tang, and E.I. Thorsos, "Acoustic penetration at subcritical grazing angles: Measurements and comparison with simulations based on perturbation theory," J. Acoust. Soc. Am., 108, 2510, doi:10.1121/1.1289207, 2000. |
1 Nov 2000
|
|
|
APL-UW environmental measurements during SAX99: Sediment conductivity and tomography Tang, D., K.L. Williams, D.R. Jackson, and E.I. Thorsos, "APL-UW environmental measurements during SAX99: Sediment conductivity and tomography," J. Acoust. Soc. Am., 108, 2535, 2000. |
1 Nov 2000
|
|
|
Applied Physics Laboratory participation in SAX99: Experiment design and execution Williams, K.L., D.R. Jackson, D. Tang, and E.I. Thorsos, "Applied Physics Laboratory participation in SAX99: Experiment design and execution," J. Acoust. Soc. Am., 108, 2510, 2000. |
1 Nov 2000
|
|
|
High-frequency measurements of absorption and dispersion in a a sandy sediment Jackson, D.R., K.L. Williams, D. Tang, and E.I. Thorsos, "High-frequency measurements of absorption and dispersion in a a sandy sediment," J. Acoust. Soc. Am., 108, 2511, doi:10.1121/1.1289207, 2000. |
1 Nov 2000
|
|
|
Sediment acoustic backscattering during SAX99: Measurements and models Williams, K.L., D.R. Jackson, D. Tang, and E.I. Thorsos, "Sediment acoustic backscattering during SAX99: Measurements and models," J. Acoust. Soc. Am., 108, 2511, 2000. |
1 Nov 2000
|
|
|
Underwater acoustic communication by passive phase conjugation: Theory and experiment Jackson, D.R., D. Rouseff, W.L.J. Fox, C.D. Jones, J.A. Ritcey, and D.R. Dowling, "Underwater acoustic communication by passive phase conjugation: Theory and experiment," J. Acoust. Soc. Am., 108, 2607, doi:10.1121/1.1289207, 2000. |
1 Nov 2000
|
|
|
High-Frequency Bistatic Scattering Models for Elastic Seafloors Jackson, D.R., "High-Frequency Bistatic Scattering Models for Elastic Seafloors," APL-UW TM 2-00, February 2000. |
1 Feb 2000
|
|
|
Modeling of subcritical penetration into sediments due to interface roughness Thorsos, E.I., D.R. Jackson, and K.L. Williams, "Modeling of subcritical penetration into sediments due to interface roughness," J. Acoust. Soc. Am., 107, 263-277, 2000. |
1 Jan 2000
|
|
