This PDF file contains the front matter associated with SPIE Proceedings Volume 8372, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

A series of UAS-capable multi-channel imagers have been developed under SBIR funding through NAVAIR. This paper discusses the application of these sensors to littoral observations/reconnaissance and littoral subsurface target detection. These imagers consist of a turreted multi-camera sensor head and an associated data acquisition and processing unit. A description of the sensor head, tailored for littoral operations, and the acquisition unit are given. Data collected off the coast of La Jolla, (north of San Diego) California over the last yearis used to demonstrate an environmental reconnaissance capability. The sensor systems are the EYEs series of sensors developed by Advanced Coherent Technologies, LLC (ACT). They integrate multiple 1.4 megapixel 12 bit charge-coupled devices (CCDs) into a commercial CloudCap TASE300^© turret. Each CCD is coupled with filters and optics appropriate for specific operations. The acquisition and processing system is based on the Vision4ce CPU/GPU ruggedized computer system.

Typical line-of-sight (LOS)/monostatic optical imaging systems include a laser source and receiver that are co-located on the same platform. The performance of such systems is deteriorated in turbid ocean water due to the large amount of light that is scattered on the path to and from an object of interest. Imagery collected with the LOS/monostatic system through the air/sea interface is also distorted due to wave focusing/defocusing effects. The approach of this project is to investigate an alternate, non-line-of-sight (NLOS)/bistatic approach that offers some advantages over these traditional LOS/monostatic imaging techniques. In this NLOS system the laser and receiver are located on separate platforms with the laser located closer to the object of interest. As the laser sequentially scans the underwater object, a time-varying intensity signal corresponding to reflectivity changes in the object is detected by the distant receiver. A modulated laser illuminator is used to communicate information about the scan to the distant receiver so it can recreate the image with the collected scattered light. This NLOS/bistatic configuration also enables one to view an underwater target through the air-sea interface (transmitter below the surface and receiver above the surface) without the distortions experienced with the LOS/monostatic sensor. In this paper, we will review the results of recent laboratory water tank experiments where an underwater object was imaged with the receiver both below and above the sea surface.

The orthodox approach to designing an underwater imaging system with artificial illumination has been to consider only the unscattered target photons as useable signal while looking at scattered photons as a nuisance to be mitigated. Photons scattered from the target towards the receiver cause blurring of fine target details in the collected imagery, while photons backscattered by the water column as the artificial source illuminates the target act as a veiling luminance that reduces overall image contrast. Typical performance for the Laser Line Scanner and Pulsed Range-Gated imagers can reach up to 6 attenuation lengths, which can still represent very short ranges in the turbid waters of coastal regions. In the early 1970's, with the goal of extending these performance ranges, the Visibility Laboratory explored an unconventional concept that was called imagery by means of Time Varying Intensity (TVI). TVI uses both scattered and unscattered photons from the laser-scanned target as useable signal. This novel approach enabled high-quality imagery to be collected over 20 attenuation lengths between the target and receiver. Although this system was eventually shelved, it has been resurrected by using a modulated laser illuminator to communicate critical information about the laser scan to a distant receiver via both the scattered and unscattered photons. With this knowledge, a high-fidelity image of target detail can then be recreated. In this paper, a real-time interactive simulation of TVI's expected imaging performance is presented and model predictions are compared with experimental imagery acquired when laser and receiver are both located underwater.

The link between suspended particle fields, particle dynamics and bulk optical properties in natural waters is poorly known because adequate technology is lacking to fully characterize critical parameters and interactions, especially for ephemeral bubbles and aggregates. This paper highlights the capabilities of digital holography to provide non-intrusive, high-resolution 3-D imaging of particles and bubbles in their natural environment. As part of a NOPP project (HOLOCAM) to commercialize an in-situ digital holographic microscope (DHM), field data with a prototype in-situ DHM (the "Holosub") were collected in East Sound, WA. The Holosub, an in-line holography based submersible platform, was deployed in two configurations: free-drifting mode for vertical profiling, and towed mode. In free-drifting mode, vertical profiles of shear strain and dissipation rates, undisturbed size and spatial distributions of particles and organisms, and the orientation of diatom chains were recorded using the holographic images. Hydrographic and optical data, as well as discrete water samples to identify phytoplankton species were concurrently collected. In towed mode, the size and spatial distributions of bubbles just below the surface were recorded to characterize the dissipation of a wake generated by another ship, and compared to optical and acoustic scattering data recorded simultaneously. Tools to extract the size distribution and concentration of bubbles from the holographic data were developed. A preliminary data analysis indicated high concentrations of bubbles detected by all three instruments at the same locations, while comparison of the bubble size distributions indicated some similarities in trends, as well as significant differences.

The Bahamas Optical Turbulence Exercise (BOTEX) was conducted in the coastal waters of Florida and the Bahamas from June 30 to July 12 2011, onboard the R/V FG Walton Smith. The primary objective of the BOTEX was to obtain field measurements of optical turbulence structures, in order to investigate the impacts of the naturally occurring turbulence on underwater imaging and optical beam propagation. In order to successfully image through optical turbulence structures in the water and examine their impacts on optical transmission, a high speed camera and targets (both active and passive) were mounted on a rigid frame to form the Image Measurement Assembly for Subsurface Turbulence (IMAST). To investigate the impacts on active imaging systems such as the laser line scan (LLS), the Telescoping Rigid Underwater Sensor Structure (TRUSS) was designed and implemented by Harbor Branch Oceanographic Institute. The experiments were designed to determine the resolution limits of LLS systems as a function of turbulence induced beam wander at the target. The impact of natural turbulence structures on lidar backscatter waveforms was also examined, by means of a telescopic receiver and a short pulse transmitter, co-located, on a vertical profiling frame. To include a wide range of water types in terms of optical and physical conditions, data was collected from four different locations. . Impacts from optical turbulence were observed under both strong and weak physical structures. Turbulence measurements were made by two instruments, the Vertical Microstructure Profiler (VMP) and a 3D acoustical Doppler velocimeter with fast conductivity and temperature probes, in close proximity in the field. Subsequently these were mounted on the IMAST during moored deployments. The turbulence kinetic energy dissipation rate and the temperature dissipation rates were calculated from both setups in order to characterize the physical environments and their impacts. Beam deflection by multiple point patterns are examined, using high speed camera recordings (300 to 1200 fps), in association with measured turbulence structures. Initial results confirmed our hypothesis that turbulence impacted optical transmissions. They also showed that more research will be needed to better quantify and mitigate such effects, especially for the U.S. Navy's next generation EO systems, including active imaging, lidar and optical communications.

A Brillouin LIDAR approach to range-resolved, remote measurements of sound speed (and temperature) in the ocean is described. Two greatly simplified versions can also provide (1) for very accurate measurements of the particulate scattering function βp(θ) at θ =180°, and (2) for detection and identification of submerged objects. For sound speed (temperature), realistic objectives are an accuracy of 0.2 m/s (0.1°C) over a range of the order of 100 m in clear ocean with a range resolution of approximately 1 m. Our approach provides high-resolution spectroscopic capabilities even in very severe vibration environments; it is based on the use of edge filters to provide a high-resolution determination of the Brillouin frequency shifts. The simplest edge filters are molecular iodine absorption lines; they have been used for the laboratory data to be presented. But, even more promising are excited-state Faraday anomalous dispersion optical filters that are nearing fruition. Our transmitter is a commercial, injection seeded, frequency-doubled Nd:YAG laser that we have modified in two ways. First, we changed its operating temperature to obtain lasing at a frequency consistent with our choice of iodine absorption lines. Second, we implemented the Ramp and Fire technique we had developed so that the laser operates in a single longitudinal mode even when there are severe environmental disturbances. Test results clearly demonstrate the efficacy of this new concept.

Infrared imaging, in both laboratory and field settings, has become a vital tool in diagnosing near-surface thermalhydrodynamic phenomena such as convective cells, accumulation of surfactant, and coherent turbulent structures. In this presentation, we initially focus on a laboratory scale (0.01-1m) subsurface vertical turbulent water jet that serves as a canonical flow. The jet has a slightly elevated temperature thus the warmer fluid serves as a passive marker. Infrared image sequences of the surface thermal field were collected for various water jet flow rates and for both "clean" and surfactant-contaminated surface conditions. Turbulent characteristics of the near-surface flow field were measured by means of Digital Particle Image Velocimetry (DPIV), and these are used to examine the statistical nature of the coupled thermal-hydrodynamic field. An analog of the laboratory jet is the discharge of power-plant cooling water through a vertical pipe on the ocean floor. High-resolution airborne infrared imagery has recently been acquired of such a discharge (from the Huntington Beach Generating Station, CA), and these data are compared with the laboratory results in an attempt to understand striking spatial patterns discovered on the ocean surface.

The drive for Ocean pollution prevention requires a significant increase in the extent and type of monitoring of subsea hydrocarbon production equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such monitoring systems will all require to be powered. Conventionally electrical powering is supplied by standard subsea electrical cabling. The ability to visualise the assets being monitored and any changes or faults in the equipment is advantageous to an overall monitoring system. However the effective use of video cameras, particularly if the transmission of real time high resolution video is desired, requires a high data rate and low loss communication capability. This can be challenging for heavy and costly electrical cables over extended distances. For this reason optical fibre is often adopted as the communication channel. Using optical fibre cables for both communications and power delivery can also reduce the cost of cabling. In this paper we report a prototype optically remote powered subsea video monitoring system that provides an alternative approach to powering subsea video cameras. The source power is transmitted to the subsea module through optical fibre with an optical-to-electrical converter located in the module. To facilitate intelligent power management in the subsea module, a supercapacitor based intermediate energy storage is installed. Feasibility of the system will be demonstrated. This will include energy charging and camera operation times.

This abstract describes the preliminary design concept for an integration system of SAR and AIS data. SAR sensors are used to acquire image data over large coverage area either through the space borne or airborne platforms in UTC. AIS reports should also obtained on the same date as of the SAR acquisition for the purpose to perform integration test. Once both data reports are obtained, one need to match the timings of AIS data acquisition over the SAR image acquisition time with consideration of local time and boundary to extract the closest time signal from AIS report in order to know the AIS based ship positions, but still one cannot be able to distinguish which ships have the AIS transponder after projection of AIS based position onto the SAR image acquisition boundary. As far as integration is concerned, the ship dead-reckoning concept is most important forecasted position which provides the AIS based ship position at the time of SAR image acquisition and also provides the hints for azimuth shift which occurred in SAR image for the case of moving ships which moves in the direction perpendicular to the direction of flight path. Unknown ship's DR estimation is to be carried out based on the initial positions, speed and course over ground, which has already been shorted out from AIS reports, during the step of time matching. This DR based ship's position will be the candidate element for searching the SAR based ship targets for the purpose of identification and matching within the certain boundary around DR. The searching method is performed by means of estimation of minimum distance from ship's DR to SAR based ship position, and once it determines, so the candidate element will look for matching like ship size match of DR based ship's dimension wrt SAR based ship's edge, there may be some error during the matching with SAR based ship edges with actual ship's hull design as per the longitudinal and transverse axis size information obtained from the AIS reports due to blurring effect in SAR based ship signatures, once the conditions are satisfied, candidate element will move and shift over the SAR based ship signature target with the minimum displacement and it is known to be the azimuth shift compensation and this overall methodology are known to be integration of AIS report data over the SAR image acquisition boundary with assessment of time matching. The expected result may provide the good accuracy of the SAR and AIS contact position along with dimension and classification of ships over SAR image. There may be possibilities of matching speed and course from candidate element with SAR based ship signature, but still the challenges are presents in front of us that to estimation of speed and course by means of SAR data, if it may be possible so the expected final result may be more accurate as due to extra matching effects and the results may be used for the near real time performance for ship identification with help of integrated system design based on SAR and AIS data reports.

Spills of Group V heavy oils are a concern because once spilled heavy oils will immediately sink to the bottom and can harm wetlands, beaches, and marine life. Recently, we developed a new tool-fluorescence polarization (FP)- for locating heavy oil deposits. The method relies on the observation that heavy, viscous oil fractions exhibit polarized fluorescence while the ubiquitous fluorescence background characteristic of chlorophyll and humic compounds do not. The basic FP measurement entails exciting the fluorophore with polarized light and observing the intensities of the emission polarized perpendicular and parallel to it. Heavy, tarry oils containing higher molecular weight polynuclear aromatic hydrocarbons fractions exhibit strong FP. The development of a remotely operated, submersible FP instrument will be presented, as well as testing results of the instrument in a simulated spill set up by the US Coast Guard at the National Oil Spill Response Research and Renewable Energy Test Facility (OHMSETT). The FP instrument utilizes a laser (532 nm) to excite the oil matrix. A small refracting telescope with variable focus is employed as the front optics and used to focus the laser beam and to collect the polarized fluorescence from the sample at a standoff distance. An embedded computer resides inside and controls the various operations such as autofocusing of the telescope and data acquisition. The embedded computer also allows autonomous or remotely controlled operation. FP along with phase sensitive detection combines to provide excellent sunlight rejection, thus allowing the use of the instrument during daylight hours.

In the case of oil spill accident at sea, cause the bad effect onto the around sea area such as ocean pollution, property loss etc. Quick making response strategies must be need to prevent additional damage and that is possible by developing system with offered integrated information, such as accident position, oil spill area, oil spill trajectories and combating resources. This paper presents the GIS system for visualization of oil spill monitoring and predicting movement. The purpose of this system is to easily understand of integrated oil spill information by plot on a program base on electronic navigation chart. Oil spill analysis tool is offer input data such as outline coordinates of detected oil spill, the information about the source satellite image and any possible sources in satellite image. This system is designed to plot oil spill on specific time and predicting oil spill trajectories with currents and winds. Each data is extracted by computer modeling using MATLAB. Oil spill movement must be superimposed both 100% of the current strength and 3% of the wind speed. The system will be developed and planned to monitor and forecast oil spilled area. At the same time, it will be planned to predict a projected path of oil spill by collecting environmental information.

Crude oil is a complex mixture of hydrocarbons (e.g. paraffins, aromatics, napthenes), sulphur compounds (e.g. sulphur, sulphides), amines, metals (e.g. Ni, Fe) and salts (e.g. NaCl, sand). Quantitative chemical analysis of such combinations is difficult and requires partial or complete separation of the components, challenging outside of the laboratory. Qualitative chemical analysis of oil is simpler using techniques such fluorescence spectroscopy. In this paper we will present fluorescence (spectra and lifetime) data for crude oil samples of varying (specific) API gravity and show how qualitative chemical information can be extracted from the spectra. This will include data obtained using synchronous scanning fluorescence spectrometry (SS) and time-resolved emission spectroscopy (TRES) and demonstrate the ability of utilising these methods to obtain better qualitative chemical information and hence the ability to "fingerprint" crude oil.

The Visible Infrared Imager Radiometer Suite (VIIRS) is successfully operating on the Suomi National Polar-orbiting Partnership (NPP) observatory, launched on October 28, 2011. Numerous components of the prelaunch test program for sensor bands centered below 1 μm were dictated by the performance requirements for ocean-color (OC) retrievals; several of these characterization activities evolved from those for the legacy sensor, the Moderate Resolution Imaging Spectroradiometer (MODIS). Addition of the Traveling Spectral Radiance and Irradiance Responsivity Calibration Using Uniform Sources (TSIRCUS) laser-based test source provided superior characterization for spectral testing and for radiometric response knowledge. Analysis suggests that band-to-band radiometric uncertainty is well below 0.5% for the OC bands, and resolution of spectral characteristics are known to better than 0.1 nm. The expected improvements in VIIRS performance testing from using T-SIRCUS and some benefits that accrue from these tests are reviewed.

The Joint Polar Satellite System (JPSS) launched the Suomi National Polar-Orbiting Partnership (NPP) satellite including the Visible Infrared Imager Radiometer Suite (VIIRS) on October 28, 2011 which has the capability to monitor ocean color properties. Four months after launch, we present an initial assessment of the VIIRS ocean color products including inter-comparisons with satellite and in situ observations. Satellite ocean color is used to characterize water quality properties, however, this requires that the sensor is well characterized and calibrated, and that processing addresses atmospheric correction to derive radiometric water leaving radiance (nLw ). These radiometric properties are used to retrieve products such as chlorophyll, optical backscattering and absorption. The JPSS ocean calibration and validation program for VIIRS establishes methods and procedures to insure the accuracy of the retrieved ocean satellite products and to provide methods to improve algorithms and characterize the product uncertainty. A global monitoring network was established to integrate in situ data collection with satellite retrieved water leaving radiance values from ocean color satellites including Moderate Resolution Imaging Spectroradiometer (MODIS), MEdium Resolution Imaging Spectrometer (MERIS) and VIIRS. The global network provides a monitoring capability to evaluate the quality of the VIIRS nLw in different areas around the world and enables an evaluation and validation of the products using in situ data and other satellites. Monitoring of ocean color satellite retrievals is performed by tracking the "gain" at the Top of the Atmosphere (TOA) and then performing a vicarious adjustment fo reach site. VIIRS ocean color products are compared with MODIS and MERIS retrieved nLw and chlorophyll, and have been shown to provide similar quality. We believe that VIIRS can provide a follow-on to MODIS and MERIS equivalent ocean color products for operational monitoring of water quality. Additional research, including an assessment of stability, a full characterization of the sensor and algorithm comparisons is underway. Weekly sensor calibration tables (look up tables) are produced by JPSS and an evaluation of their impact on ocean color products is ongoing.

The Suomi National Polar-orbiting Partnership (NPP) satellite was placed in orbit October 28, 2011, and began providing advanced imaging and radiometric data from the Visible Infrared Imager Radiometer Suite (VIIRS) in December 2011. The Naval Oceanographic Office (NAVOCEANO) is processing the VIIRS data as part of the generation of sea surface temperature (SST) retrievals for ingest by Navy meteorological and oceanographic analyses and models. This new sensor has an increased number of channels, higher resolution, and larger volume than previous operational polar-orbiting environmental satellites. In order to prepare for processing this new data, a proxy datastream was generated by the Government Resource for Algorithm Verification, Independent Testing, and Evaluation (GRAVITE) from Moderate-resolution Imaging Spectroradiometer (MODIS) data and provided in near real-time. This allowed for NAVOCEANO to write software to ingest, process, and deliver SST products before the actual data began flowing. A discussion of these preparatory activities and the initial results of processing VIIRS SSTs will be presented, including global drifting buoy matchup statistics.

Automated match ups allow us to maintain and improve the products of current satellite ocean color sensors (MODIS, MERIS), and new sensors (VIIRS). As part of the VIIRS mission preparation, we have created a web based automated match up tool that provides access to searchable fields for date, site, and products, and creates match-ups between satellite (MODIS, MERIS, VIIRS), and in-situ measurements (HyperPRO and SeaPRISM). The back end of the system is a 'mySQL' database, and the front end is a `php' web portal with pull down menus for searchable fields. Based on selections, graphics are generated showing match-ups and statistics, and ascii files are created for downloads for the matchup data. Examples are shown for matching the satellite data with the data from Platform Eureka SeaPRISM off L.A. Harbor in the Southern California Bight.

The objective of this work is to determine the location(s) in any given oceanic area during different temporal periods where in situ sampling for Calibration/Validation (Cal/Val) provides the best capability to retrieve accurate radiometric and derived product data (lowest uncertainties). We present a method to merge satellite imagery with in situ measurements, to determine the best in situ sampling strategy suitable for satellite Cal/Val and to evaluate the present in situ locations through uncertainty indices. This analysis is required to determine if the present in situ sites are adequate for assessing uncertainty and where additional sites and ship programs should be located to improve Calibration/Validation (Cal/Val) procedures. Our methodology uses satellite acquisitions to build a covariance matrix encoding the spatial-temporal variability of the area of interest. The covariance matrix is used in a Bayesian framework to merge satellite and in situ data providing a product with lower uncertainty. The best in situ location for Cal/Val is then identified by using a design principle (A-optimum design) that looks for minimizing the estimated variance of the merged products. Satellite products investigated in this study include Ocean Color water leaving radiance, chlorophyll, and inherent and apparent optical properties (retrieved from MODIS and VIIRS). In situ measurements are obtained from systems operated on fixed deployment platforms (e.g., sites of the Ocean Color component of the AErosol RObotic NETwork- AERONET-OC), moorings (e.g, Marine Optical Buoy-MOBY), ships or autonomous vehicles (such as Autonomous Underwater Vehicles and/or Gliders).

Advanced Clear-Sky Processor for Oceans (ACSPO) is a National Environmental Satellite, Data, and Information Service (NESDIS) clear-sky radiance and sea surface temperature (SST) retrieval system. It provides clearsky top of the atmosphere (TOA) observed brightness temperatures (BT) in AVHRR channels 3B(3.7 μm), 4(11 μm), and 5(12 μm) and SST retrieved from these BTs, along with their modeled values calculated with the fast community radiative transfer model (CRTM), using first-guess level 4 (L4) SST (Reynolds daily optimum interpolation SST; OISST) and upper air (NCEP-GFS) fields as inputs. The simulated first-guess BTs are used for accurate ACSPO clearsky mask estimation, physical SST retrievals, monitoring sensor performance, and CRTM validation. Model minus observation (M-O) biases are continuously monitored using the near-real time online-tool, Monitoring of IR Clear-sky radiances over Oceans for SST (MICROS; www.star.nesdis.noaa.gov/sod/sst/micros/). This study tests eleven different gap free L4 SSTs as potential first-guess input fields in ACSPO to improve accuracies of simulated BTs. These L4 SST fields are being cross-compared and validated with quality controlled in situ data in L4-SST Quality Monitor (SQUAM; http://www.star.nesdis.noaa.gov/sod/sst/squam/L4/). In this paper, L4 SSTs are evaluated by comparing them with the ACSPO L2 SST product. Three metrics including the global spatial variance of the L4-L2 biases, and their temporal stability along with the corresponding double-differences, are used to test the performance of these L4 SSTs. It is generally observed that the Group for High-Resolution SST (GHRSST) Multi-Product Ensemble (GMPE), Canadian Meteorological Centre (CMC 0.2°) and UKMO OSTIA provide more consistent first-guess SST fields for use in ACSPO.

In Ocean Color (OC) data processing one of the most critical steps is the atmospheric correction procedure used to separate the water leaving radiance, which contains information on water constituents, from the total radiance measured by space borne sensors, which contains atmospheric contributions. To ensure reliability of retrieved water leaving radiance values, and OC information derived from them, the quality of the atmospheric correction procedures applied needs to be assessed and validated. In this regard, the Long Island Sound Coastal Observatory (LISCO), jointly established by the City College of New York and the Naval Research Laboratory is becoming one of the key elements for OC sensors validation efforts, in part because of its capabilities for co-located hyper and multi-spectral measurements using HyperSAS and SeaPRISM radiometers respectively, with the latter being part of the NASA AERONET - OC network. Accordingly, the impact of the procedures used for atmospheric correction on the retrieval of remote sensing reflectance (R_rs) data can then be evaluated based on satellite OC data acquired from the LISCO site over the last two years. From this, the qualities of atmospheric correction procedures are assessed by performing matchup comparisons between the satellites retrieved atmospheric data and that of LISCO.

LIght Detection and Ranging (LIDAR) systems have been used most extensively to generate elevation maps of land, ice and coastal bathymetry. There has been space-, airborne- and land-based LIDAR systems. They have also been used in underwater communication. What have not been investigated are the capabilities of LIDARs to measure ocean temperature and optical properties vertically in the water column, individually or simultaneously. The practical use of bathymetric LIDAR as a tool for the estimation of inherent optical properties remains one of the most challenging problems in the field of optical oceanography. LIDARs can retrieve data as deep as 3-4 optical depths (e.g. optical properties can be measured through the thermocline for ~70% of the world's oceans). Similar to AUVs (gliders), UAV-based LIDAR systems will increase temporal and spatial measurements by several orders of magnitude. The LIDAR Observations of Optical and Physical Properties (LOOPP) Conference was held at NURC (2011) to review past, current and future LIDAR research efforts in retrieving water column optical/physical properties. This new observational platform/sensor system is ideally suited for ground truthing hyperspectral/geostationary satellite data in coastal regions and for model data assimilation.

Subsurface profiling LIDAR systems extend our understanding of ocean processes "below" the ocean surface of SST and ocean color. Time-gated LIDAR backscattering intensity has been shown to define the bio-optical ocean layers and characterize subsurface processes. The interaction between the mixed layer depth (MLD) using vertical temperature structures and LIDAR optical layers provides a critical link between physical and bio-optical processes. We evaluated the capability of LIDAR penetration to reach the MLD on a global basis. Penetration depths of LIDAR were estimated using attenuation depths derived from global monthly ocean color averages which were assumed vertically homogenous. Climatology of LIDAR penetration depth was combined with the monthly mixed layer depth determined from the Global NCOM ocean circulation model. Global NCOM output was used to construct monthly averaged MLD climatologies from 2002 to 2010. Results show how monthly changes in MLD and LIDAR penetration depths are coupled for different regions of the global ocean. For example, the time-lag in LIDAR penetration depths is linked to shallowing of the MLD in the North Atlantic Bloom. We estimate the percentage of global ocean waters where different LIDAR system configurations can reach below the MLD. Results illustrate the potential performance of LIDAR systems to "probe" the subsurface for global waters which help in LIDAR design. Subsurface processes such as mixing and biological growth and decay have significant impact on what we observe at the ocean surface. LIDAR profiling should provide the new dimension for monitoring global ocean processes.

A dual polarization lidar was used to sense internal waves from a small aircraft. Internal waves are gravity waves that are formed by a vertical displacement of a density gradient in the ocean. If the perturbation is great enough, a nonlinear wave is produced and the balance between nonlinearity and dispersion can create a soliton-like wave packet. We observed nonlinear wave packets in West Sound, Orcas Island, Washington. In this region, a density gradient is formed in the summer by solar heating of the surface water. The perturbation is produced by strong tidal flow through a narrow, shallow channel at the mouth of the sound. Plankton layers form in association with the density gradients, and these layers produce an enhanced lidar return that moves up and down with the wave. We observed these internal waves with a lidar operating at 532 nm. They were much more visible when the receiver was polarized orthogonal to the transmitted laser pulse. This was the case whether linear or circular polarization was used, with no significant difference between the two cases. These internal waves were also visible to the naked eye, when the surface currents produced by the waves modulated the small surface waves that produce the apparent texture of the ocean surface.

Recent progress in system hardware such as laser, photon detectors and other electronic and optical components resulted in significant improvement for the underwater serial laser imaging system. Nevertheless, during normal system operation, system issues such as laser instability, electronic noise, and environmental conditions such as imaging in highly turbid water can still put constraint on the performance of imager. In this work, post-processing to take advantage of the improvement hardware to further reduce image noise and enhance the image quality as a critical aspect of the overall system design is studied. A novel realization of the bilateral principle based image/pulse noise reduction and image deconvolution using point spread function (PSF) predicted with EODES radiative transfer model is used to implement the processing chain. The concept is further extended to a multichannel deconvolution to exploit the benefit offered by the new multi element PMT configuration developed in HBOI. Two datasets were used to test the developed techniques respectively.

A new, modulated-pulse, technique is currently being investigated for underwater laser detection, ranging, imag- ing, and communications. This technique represents a unique marriage of pulsed and intensity modulated sources. For detection, ranging, and imaging, the source can be congured to transmit a variety of intensity modulated waveforms, from single-tone to pseudorandom code. The utility of such waveforms in turbid underwater envi- ronments in the presence of backscatter is investigated in this work. The modulated pulse laser may also nd utility in underwater laser communication links. In addition to exibility in modulation format additional variable parameters, such as macro-pulse width and macro-pulse repetition rate, provide a link designer with additional methods of optimizing links based on the bandwidth, power, range, etc. needed for the application. Initial laboratory experiments in simulated ocean waters are presented.

The next generation of Ocean Color satellite sensors (PACE, NASA) will have polarization sensitive channels which will make possible to continue the time series of polarization acquisitions from space initiated by the French missions POLDER/PARASOL (CNES) and can be used to acquire additional information on ocean water constituents. The water attenuation coefficient is not retrievable by the exclusive use of the unpolarized measurements of the water-leaving radiance. However, we recently showed that the underwater degree of linear polarization (DoLP) can be fairly related to the attenuation/absorption ratio (c/a) which enables us to achieve retrievals of the absorption and attenuation coefficients from measurements of the Stokes components of the upwelling underwater light field. The relationship between the DoLP and the attenuation/absorption (c/a) ratio is investigated based on vector radiative transfer simulations of the underwater polarized light field for several wavelengths in the visible part of the spectrum, for a complete set of viewing geometries and for varying water compositions with water constituents include phytoplankton, non-algal particles and CDOM. It is shown that the relationship that exists between DoLP and c/a ratio has an excellent correlation for wide range of different viewing and Sun's geometries opening the possibility for air or space borne DoLP measurements of the ocean and therefore retrieval of additional water optical properties.

Thin layers are water column structures that contain concentrations of organisms (or particles) that occur over very small vertical scales (a few meters or less), but with large horizontal scales (e.g. kilometers). Thin layers are now known to be common phenomenon in a wide variety of environments and can be a critical componant in marine ecosystem dynamics and functioning. While knowledge about their dynamics is important to our basic understanding of oceanic processes, thin layers can have significant impacts on both oceanographic and defense related sensing systems, e.g. thin layers can affect underwater visibility, imaging, vulnerability, communication and remote sensing for both optical and acoustic instrumentation. This paper will review the history of thin layers research, their ecological significance, innovations in oceanographic instrumentation and sampling methodologies used in their study, and the consequences of their occurence to oceanographic sensing systems.

A 3D ocean optical forecast system called TODS (Tactical Ocean Data System) has been developed to determine the performance of underwater LIDAR detection/identification systems. TODS fuses optical measurements from gliders, surface satellite optical properties, and 3D ocean forecast circulation models to extend the 2-dimensional surface satellite optics into a 3-dimensional optical volume including subsurface optical layers of beam attenuation coefficient (c) and diver visibility. Optical 3D nowcast and forecasts are combined with electro-optical identification (EOID) models to determine the underwater LIDAR imaging performance field used to identify subsurface mine threats in rapidly changing coastal regions. TODS was validated during a recent mine warfare exercise with Helicopter Mine Countermeasures Squadron (HM-14). Results include the uncertainties in the optical forecast and lidar performance and sensor tow height predictions that are based on visual detection and identification metrics using actual mine target images from the EOID system. TODS is a new capability of coupling the 3D optical environment and EOID system performance and is proving important for the MIW community as both a tactical decision aid and for use in operational planning, improving timeliness and efficiency in clearance operations.

Since its launch, the Enhanced Thematic Mapper plus (ETM+) onboard Landsat-7 has been continuously monitored via different calibration techniques to ensure it maintains the science requirements for the demanding application areas. The majority of its applications, including agriculture and forestry, require a robust calibration for medium to high reflective targets. However, when imaging water resources, then the question becomes whether the calibration coefficients are valid for the dark end of the sensor's responsivity curve. Motivated by the Landsat Data Continuity Mission (LDCM) and its potential for providing long-term, robust water studies, in this effort, the calibration status of Landsat-7's visible bands are examined using a cross-calibration technique. The well-calibrated Terra-MODIS scenes of the past decade over relatively optically stable waters were chosen to evaluate Landsat-7's stability. Following the geo-registration, homogenous areas exhibiting near, identical atmospheric conditions were specified as regions of interest in the calibration sites representing a broad range of water-leaving signals. The differences in the relative spectral response functions of the two sensors were accounted for via a model-based technique. The cross-comparison showed that the calibration instability of Landsat-7's reflective bands lie well within its radiometric uncertainty. The slight calibration differences were found to be less than 1%, 0.5%, and 2.5% for the blue, green and the red bands obtained for the period when the Terra-MODIS has been radiometrically stable. The Landsat-7's NIR band, however, exhibits, on average, 6.3% higher signals than those of Terra-MODIS. The results indicate that although Landsat-7 is well calibrated, its calibration status should be quantified rigorously for water studies when physics-based methods are employed for the removal of atmospheric effects. The over-water characterization of Landsat satellites becomes more crucial when the LDCM becomes operational.

The Operational Land Imager (OLI) is a new sensor being developed by the joint USGS-NASA Landsat Data Continuity Mission that exhibits an exciting potential to be used for monitoring Case 2 waters. With upgrades such as a Coastal Aerosol band, 12 bit quantization, and improved signal-to-noise, preliminary studies indicate that OLI should be radiometrically superior to its predecessors. Considering that OLI will have the traditional 30m resolution of other Landsat instruments, and that its data is free to the community, this sensor should be an invaluable tool for long-term monitoring of water quality in Case 2 waters, especially in the nearshore environment. Through the use of simulated data, previous research indicates that OLI can retrieve the levels of three main water quality indicators (chlorophyll, suspended materials, and colored-dissolved organic matter (CDOM)) to within 7% of their expected range when atmospheric effects are ignored. Since the atmosphere typically represents a major source of error when quantifying water constituents from space, significant efforts have been made to develop techniques that will accurately remove atmospheric effects from OLI data. As OLI is an instrument designed for land-based studies, it will not be equipped with the appropriate bands required by traditional water-based atmospheric correction algorithms. This work presents a new atmospheric correction technique that was developed specifically for the OLI instrument. Preliminary results indicate that when atmospheric effects are included, OLI can retrieve the levels of the three water parameters to within 15% of their expected range, which is within the desired error range for this type of research.

In recent years, forward-scan sonar is widely applied to the underwater inspection, which is not subject to the influence of light and turbidity. For expanding the monitoring scope, the image sonar is generally mounted on the pan-tilt platform of a ROV (Remotely Operated Vehicle) or survey boat. However, there are still some problems such as: 1) The field-of-view is narrow, i.e. the horizontal view angle of DIDSON (Dual-frequency identification sonar) is 29°; 2) The dynamic change of a ROV or survey boat by the water disturbances will cause the target to escape from the sonar image easily; 3) The image sonar is fixed on the pan-tilt platform, and its position and posture are unceasingly changed. As a result of these problems, the obtained images may be distorted and not on the same plane. To solve the above problems, stability augmentation of pan-tilt platform based on the principle of bionic eye movements and a mosaic method of sonar images are presented. According to the principle of the vestibule-ocular reflex, an active compensation control system of the mechanical pan-tilt platform is developed. It can compensate the sonar image instability resulting from attitude variation of a ROV or survey boat during operation. Applying multi-sensor fusion technology can rectify the sonar images with different position and posture to be on a single geodetic coordinate frame for image matching. Finally, sonar images can be mosaic. A stable large-scale sonar image can be obtained. The experimental results validate that the presented method is valid.

This paper reports on performance of a previously reported sonar watermarking algorithm in actual sea trials. Tests were conducted at the South Florida Ocean Measurement Facility in shallow water depths of 200m and a range of 7km subject to a 80dB propagation loss. The watermark was designed to match the acoustic channel simulated in the Sonar Simulation Toolset (SST), but no access to the actual acoustic channel was available prior to the test. Watermark detection was carried out over multiple ping cycles. For a 10-ping cycle, it was possible to achieve zero false alarm and a single miss at SWR=27dB. At SWR=30dB, zero false alarm was maintained but the miss rate increased to three. This experiment has rearmed the detectability of the watermark in actual sea deployment.

Data from the radar and an absolute pressure gauge collected from Verem, Goa over a period of one year- January, 2009 to May, 2010 is used to carry out the comparative studies. The root mean square difference between the estimated sea level using radar and pressure gauge with atmospheric pressure correction is ~ 2.6 cm. The harmonic analysis over the two time series produces similar residuals and tidal constituents. The results from the study indicate the importance of concurrent measurement of atmospheric pressure along with sub-bottom absolute pressure gauge. The radar gauge has advantages over other type of gauges with regard to easy installation, maintenance and also sea level measurements are absolute and could be given precedence in future applications.

The role of dense coconut palms in attenuating the wind speed at Kavaratti Island, which is located in the southeastern Arabian Sea, is examined based on land-based and offshore wind measurements (U₁₀) using anchored-buoy-mounted and satellite-borne sensors (QuikSCAT scatterometer and TMI microwave imager) during an 8-year period (2000-2007). It is found that round the year monthly-mean wind speed measurements from the Port Control Tower (PCT) located within the coconut palm farm at the Kavaratti Island are weaker by 15-61% relative to those made from the nearby offshore region. Whereas wind speed attenuation at the island is ~15-40% in the mid-June to mid-October south-west monsoon period, it is ~41-61% during the rest of the year. Wind direction measurements from all the devices overlapped, except in March-April during which the buoy measurements deviated from the other measurements by ~20°. U₁₀ wind speed measurements from PCT during the November 2009 tropical cyclone "Phyan" indicated approximately 50-80% attenuation relative to those from the seaward boundary of the island's lagoon (and therefore least influenced by the coconut palms). The observed wind speed attenuation can be understood through the theory of free turbulent flow jets embodied in the boundary-layer fluid dynamics, according to which both the axial and transverse components of the efflux of flows discharged through the inter-leaves porosity (orifice) undergo increasing attenuation in the downstream direction with increasing distance from the orifice. Thus, the observed wind speed attenuation at Kavaratti Island is attributable to the decline in wind energy transmission from the seaward boundary of the coconut palm farm with distance into the farm. Just like mangrove forests function as bio-shields against forces from oceanic waves and stormsurges through their large above-ground aerial root systems and standing crop, and thereby playing a distinctive role in ameliorating the effects of catastrophies such as hurricanes, tidal bores, cyclones, and tsunamis, the present study provides an indication that densely populated coconut palms and other tall tree vegetation would function as bio-shields against the damaging effects of storms through attenuation of wind speed.

Most of the devastations wrecked by a tropical cyclone occur on land, and therefore, its longevity after landfall is of critical importance. Published literature identifies many factors including inland environmental characteristics that influence this longevity and power dissipation rate. These have been studied in this research in the context of tropical cyclones that hit Australian coasts during the period 1970-2003. For obvious reasons, tropical cyclones which manifested recurrence or multiple landfalls have been excluded. After performing correlation, regression, eigen analysis, and significance tests it has been found that from variables identified in literature storm intensity at landfall, translation speed, relative humidity, surface temperature, upper level divergence, and surface roughness are the significant parameters. However, stepwise regression retained only surface roughness, central pressure and longitudinal position, which yielded a coefficient of determination of 88 percent for the data. The concept of surface roughness is well understood, but hitherto, no consistent metric for the purpose of tropical cyclones' propagation existed, and therefore, this paper introduces a scheme of assigning surface roughness based on terrain characteristics.

Divers executing strategic underwater missions as well as recreational divers have a great need for communication. Divers can communicate between themselves as well as to a surface boat, to share information, perform cooperative maneuvers and call for help. In addition, it would be useful to know the location of all divers relative to the boat. Such capability will allow operators to guide divers in their maneuvers and provide immediate assistance during emergencies. We present the development of communication protocols for text messaging and the development of a relative diver locating system.

Simulation of natural oceanic conditions in a laboratory setting is a challenging task, especially when that environment can be miles away. We present an attempt to replicate the solar radiation expected at different latitudes with varying water clarity conditions up to 30 m in depth using a 2.5 m deep engineering tank at the University of New Hampshire. The goals of the study were: 1) to configure an underwater light source that produced an irradiance spectrum similar to natural daylight with the sun at zenith and at 60° under clear atmospheric conditions, and 2) to monitor water clarity as a function of depth. Irradiance was measured using a spectra-radiometer with a cosine receiver to analyze the output spectrum of submersed lamps as a function of distance. In addition, an underwater reflection method was developed to measure the diffuse attenuation coefficient in real time. Two water clarity types were characterized, clear waters representing deep, open-ocean conditions, and murky waters representing littoral environments. Results showed good correlation between the irradiance measured at 400 nm to 600 nm and the natural daylight spectrum at 3 m from the light source. This can be considered the water surface conditions reference. Using these methodologies in a controlled laboratory setting, we are able to replicate illumination and water conditions to study the physical, chemical and biological processes on natural and man-made objects and/or systems in simulated, varied geographic locations and environments.

The conventional method used to detect the range to an underwater object is by sending and receiving some form of acoustic energy. However, acoustic systems have limitations in the range resolution and accuracy they can provide under certain conditions. The potential benefits of a laser-based range finder include high-directionality and covertness, speed of response, and the potential for high-precision, range accuracy. These benefits have been exploited in the above-water environment where kilometer propagation ranges are achieved with sub-meter range precision. The challenge in using optical techniques in the underwater environment is overcoming the exponential loss due to scattering and absorption. While absorption extinguishes photons, scattering redistributes the light and produces a 'clutter' signal component from the surrounding water environment. Optical modulation techniques using compact laser diode sources are being investigated to help suppress this 'clutter' and provide accurate target range information in a wide range of underwater environments. To complement the experimental efforts, a theoretical model has been developed to help optimize the system parameters and test the performance of various configurations as a function of different water optical properties. Results from laboratory water tank experiments will be discussed and compared with model predictions.

This paper describes the development of an USV (Unmanned Surface Vehicle) prototype that serves as an educational platform and can be use for coastal patrol and operations in the jungle. The USV length is less than 2 m and range of 5000 m. It's composed by the following modules: propulsion, power, motor driver, CPU, sensor suite, camera system, communication and weapon system. The weapon system is formed by an experimental assault rifle and a rocket launcher with a fire control system. The assault rifle haven't got mechanical moving parts, the bullets (7.62x51mm round) are electronically ignited. The CPU is an FPGA development kit. The USV can be operate in remote mode or fully autonomous. Results of some systems from laboratory and sea trials are show.