This PDF file contains the front matter associated with SPIE Proceedings Volume 8532, including the Title Page, Copyright Information, Table of Contents, and the Conference Committee listing.

The SYSIPHE system is the state of the art airborne hyperspectral imaging system developed in European cooperation. With a unique wide spectral range and a fine spatial resolution, its aim is to validate and quantify the information potential of hyperspectral imaging in military, security and environment applications. The first section of the paper recalls the objectives of the project. The second one describes the sensors, their implementation onboard the platform and the data processing chain. The last section gives illustrations on the work in progress.

This study is aimed at exploring the potentials of SAR Interferometry (InSAR) to aid Unmanned Aerial Vehicles (UAV) navigation. The basic idea is to infer both position and attitude of an aerial platform by inspecting the InSAR phase derived by a real time SAR interferometer mounted onboard the platform. Thanks to the expected favorable conditions in terms of geometrical sensitivity as well as signal coherence, the InSAR phase field can be used to derive the terrain elevation. By using both approximated position and attitude values of the platform as well as a reference Digital Terrain Model (DTM) from a mission database available onboard, it is possible to generate a synthetic InSAR phase model to be compared w.r.t. that derived by SAR observations. The geometrical transformation needed to match these two terrain models depends on the difference between position and attitude values derived by the instruments available on board and their actual values. Hence, this matching provides a feedback to be used for adjusting position and attitude. In order to assess the reliability of the proposed approach, we evaluated the interferometric sensitivity to changes in position and attitude. This analysis defines the limits of applicability of the InSAR-based approach and provides indications and requirements on geometric and radiometric parameters.

CARVE-FTS is a near-IR Fourier-Transform Spectrometer (FTS) used by the Jet Propulsion Laboratory (JPL) for the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). CARVE is a 5-year mission of intensive aircraft campaigns in the Alaskan Arctic selected as part of NASA’s Earth Ventures program (EV-1). The CARVE-FTS has been designed, manufactured and tested by ABB Inc. The objective of this instrument is to provide integrated column measurements of carbon dioxide (CO₂), methane (CH₄), and carbon monoxide (CO). The system is inspired from the TSUKUBA-FTS built by ABB for the Japanese Aerospace Exploration Agency (JAXA). JAXA uses the instrument for preparation, calibration and validation within the GOSAT program. The instrument is a Michelson based FTS with three spectral bands. The light modulator is a Michelson single pass type interferometer with large aperture and medium spectral resolution. It provides infrared spectra from 12,900 cm^-1 to 13,200 cm^-1, from 5,800 cm^-1 to 6,400 cm^-1, and from 4,200 cm^-1 to 4,900 cm^-1. This instrument is also able to measure the scene radiance with S and P polarization simultaneously using monopixel detectors. The instrument is mounted on a damping platform and is installed in an aircraft. It delivers continuous data for flight campaigns over the Alaskan Arctic. SNR higher than 100 is reached for each band and the measured ILS full width at half maximum is as low as 0.26 cm^-1 at 6,566 cm^-1. We present the instrument design, its specification and test results obtained at ABB.

The Canadian Space Agency and the Defence Research and Development Canada are jointly developing an advanced miniaturized imaging spectrometer for future Mars rover and onboard a small aircraft. This work is the further development of the two previous concept studies for Mars: Canadian Hyperspectral Imager for Mars Exploration and Resource Assessment (CHIMERA) and Hyperspectral and Luminescence Observer (HALO). Based on outcomes of the concept studies, a Dyson spectrometer design was selected as the imaging spectrometer due to its compactness, high optical output and low distortion. This paper briefly describes the options of imaging spectrometers proposed in the HALO study. Then the requirements of the advanced miniaturized imaging spectrometer system are provided. Finally the preliminary results of the development of the Dyson imaging spectrometer system will be reported.

This paper explores aspects of the inter-relationships between traditional archaeological interpretation of remote sensed data (principally visual examination of aerial photographs/satellite) and those drawing on automated feature extraction and processing. Established approaches to archaeological interpretation of aerial photographs are heavily reliant on individual observation (eye/brain) in an experience and knowledge-based process. Increasingly, however, much more complex and extensive datasets are becoming available to archaeology and these require critical reflection on analytical and interpretative processes. Archaeological applications of Airborne Laser Scanning (ALS) are becoming increasingly routine, and as the spatial resolution of hyper-spectral data improves, its potentially massive implications for archaeological site detection may prove to be a sea-change. These complex datasets demand new approaches, as traditional methods based on direct observation by an archaeological interpreter will never do more than scratch the surface, and will fail to fully extend the boundaries of knowledge. Inevitably, changing analytical and interpretative processes can create tensions, especially, as has been the case in archaeology, when the innovations in data and analysis come from outside the discipline. These tensions often centre on the character of the information produced, and a lack of clarity on the place of archaeological interpretation in the workflow. This is especially true for ALS data and autoextraction techniques, and carries implications for all forms of remote sensed archaeological datasets, including hyperspectral data and aerial photographs.

Light detection and ranging (lidar) provides a promising way of detecting changes of vegetation in three dimensions (3D) because the beam of laser may penetrate through the foliage of vegetation. This study aims at the detection of changes in trees in urban areas with a high level of automation using mutil-temporal airborne lidar point clouds. Three datasets covering a part of Rotterdam, the Netherlands, have been classified into several classes including trees. A connected components algorithm was applied first to group the points of trees together. The attributes of components were utilized to differentiate tree components from misclassified non-tree components. A point based local maxima algorithm was implemented to distinguish single tree from multiple tree components. After that, the parameters of trees were derived through two independent ways: a point based method using 3D alpha shapes and convex hulls; and a model based method which fits a Pollock tree model to the points. Then the changes were detected by comparing the parameters of corresponding tree components which were matched by a tree to tree matching algorithm using the overlapping of bounding boxes and point to point distances. The results were visualized and statistically analyzed. The difference of parameters and the difference of changes derived from point based and model based methods were both lower than 10%. The comparison of these two methods illustrates the consistency and stability of the parameters. The detected changes show the potential to monitor the growth and pruning of trees.

This paper describes low altitude mobile imaging of near coastal waters in the Northern Gulf of Mexico. A suite of mobile multispectral and hyperspectral sensors were flown between ~1,000m to ~3000m altitudes in order detect subsurface features in nearby wetlands and littoral zone areas following the Deepwater Horizon oil spill. In this paper techniques used to develop, integrate and calibrate the airborne sensors are described. The sensors include a multispectral digital frame camera system, a traditional photogrammetric camera, and a small custom hyperspectral imaging system with custom software. Ancillary sensors include include multiple differential GPS and inertial motion unit (IMU) sensing systems and twin high definition video cameras for parallax related estimations. The correction of hyperspectral pushbroom imagery that utilizes Kalman filtering and smoothing is described and examples of georeferenced imagery is presented. The ability to image subsurface features is described and demonstrates not only the hyperspectral imaging system, but the value of utilizing simultaneous multisensor mobile sensing systems for environmental monitoring and surveillance of shorelines, water and nearby vegetation environments in littoral zones.

Wireless sensor netwoks (WSN) employ miniaturized devices which integrate sensing, processing, and communication capabilities. In this paper an innovative mobile platform for heterogeneous sensor networks is presented, combined with adaptive methods to optimize the communication architecture for novel potential applications even in coastal and marine environment monitoring. In fact, in the near future, WSN data collection could be performed by UAV platforms which can be a sink for ground sensors layer, acting essentially as a mobile gateway. In order to maximize the system performances and the network lifespan, the authors propose a recently developed hybrid technique based on evolutionary algorithms. This procedure is here applied to optimize the communication energy consumption in WSN by selecting the optimal multi-hop routing schemes, with a suitable hybridization of different routing criteria. The proposed approach can be potentially extended and applied to ongoing research projects focused on UAV-based remote sensing of the ocean, sea ice, coastal waters, and large water regions.

The goal of the project is the working out of a multichannel spectrometric system in the visible and near infrared bands of the electromagnetic spectrum for remote sensing with the following purposes: recognition of main land covers (soils, natural and agricultural vegetation, water areas); state assessment of the studied objects. The multichannel spectrometric system is designed to measure the reflected by ground objects solar radiation in the visible and near infrared range of the electromagnetic spectrum on board of a remotely-controlled airborne platform (helicopter). The measurements will be performed in a main working regime - nadir, helicopter velocity – up to 20 km/h, height – up to 1000 m (optimal 200 m), flight duration - up to 30 min. Components of the system are: multichannel spectrometer; digital camera (optional); data control on-board system; onboard power supply device; fitting elements for installation on board; ground-based computing system for storage and processing of spectrometric data. Technical specifications of the spectrometric system are: spectral VIS-NIR range (450-900) nm; number of spectral channels 128–64; channel location even; spectral resolution (3-10) nm; spatial resolution (1-25) m²; CCD line elements 2048; dynamic range of the system 4 x 104 and per scan 2000:1; exposure time (3-60) ms; measurement flight duration (10-30) min. Main tasks are investigation of the relationships between the reflectance and biophysical features of the studied objects; development and validation of spectral-biophysical models for estimation of land cover parameters; soil state assessment (type, moisture content, surface texture); vegetation state assessment (type, phenological and growth parameters, detection of stress situations) and emergency response.

We present a detailed investigation on the temperature-dependence of polarized and unpolarised Raman spectra for various laboratory water, fresh and saltwater samples. We have identified the spectral parameters which are most sensitive to water temperature, and compared these between the water samples from different locations. We have then applied linear regression methods and multiple linear regression methods to investigate the accuracy with which water temperature can be estimated from Raman spectral data.

Analysis of coastal marine algae communities enables an estimation of the state of coastal marine environments and provides evidence for environmental changes. Hyperspectral remote sensing provides a tool for mapping macroalgal habitats if the algal communities are spectrally resolvable. We tested the performance of a new approach for determining the distribution of macroalgae communities in the rocky intertidal zone of Helgoland (Germany) using airborne hyperspectral (AISA_eagle) data. This new approach calculates the slopes in wavelength regions between specific pigment absorption features and does not rely on absolute reflectance values. The first order derivatives of these wavelength regions form slope bands, which are then classified using a k-Means approach. The new derivatives approach proved to be a time effective possibility for identifying the dominating macroalgae species with sufficient accuracy (Cohan’s kappa = 0.70). The method was tested on another AISA data set and turned out to be as a robust (Cohan’s kappa = 0.77) and easy-to-use approach for delineating dominant algae communities or habitats, which can be adapted easily to different data sets.

Many sensor systems are available for sensing the earth surface from satellites as well as airborne and mobile platforms. Thus, fusing data from multiple sensors is becoming a common theme in earth remote sensing. A major goal of remote sensing image fusion is resolution enhancement. In this paper, optimization techniques are presented and discussed in order to help make an image fusion process a practical method for not only spectral signature based image analysis but also for algorithm development in remote sensing of water. The technique described and explored in this paper includes the identification of feature areas, stratified random pixel selection, singular value decomposition model building for synthetic image generation, and optimization of the 2D Butterworth filter cutoff and order coefficients in a spectral and spatial resolution enhancement protocol. The process is also called spatial sharpening of hyperspectral imagery as presented in this paper. Examples of methods for estimating errors in the data fusion process are also described using coastal littoral zone remote sensing imagery with an emphasis on weathered oil scenes. The optimization and testing of a data fusion methodology or protocol described utilizes image to image georeferencing methods, nearest neighborhood and linear remapping of multi-resolution spatial and spectral imagery. The central optimization procedures entails random selection of pixels from feature areas in simultaneously acquired multispectral and hyperspectral scenes in order to build multiple "SVD" singular value decomposition models and optimized selection of these image models for each hyperspectral channel based upon the non-parametric K-S p-statistical test. The model synthetic imagery is then used with the 2D discrete cosine and inverse cosine filters, a 2D Butterworth filter. Optimization of the 2D Butterworth filter cutoff and order coefficients are conducted for each hyperspectral band and these coefficients are optimized using the same K-S based tests. The above optimization protocol results in synthetic reflectance hyperspectral cube where minimization between observed and synthetic hyperspectral signatures has been performed for each hyperspectral channel. Results indicate the synthetic hyperspectral resolution enhancement methodology is most sensitive to (a) the pixels selected (from feature areas) for use in the SVD model building process and (b) the 2D Butterworth cutoff frequency selected.

In this paper it is investigated how conventional in-situ sensor networks can be complemented by the satellite data streams available through numerous platforms orbiting the earth and the combined analyses products available through services such as MyOcean. Despite the numerous benefits associated with the use of satellite remote sensing data products, there are a number of limitations with their use in coastal zones. Here the ability of these data sources to provide contextual awareness, redundancy and increased efficiency to an in-situ sensor network is investigated. The potential use of a variety of chlorophyll and SST data products as additional data sources in the SmartBay monitoring network in Galway Bay, Ireland is analysed. The ultimate goal is to investigate the ability of these products to create a smarter marine monitoring network with increased efficiency. Overall it was found that while care needs to be taken in choosing these products, there was extremely promising performance from a number of these products that would be suitable in the context of a number of applications especially in relation to SST. It was more difficult to come to conclusive results for the chlorophyll analysis.

Numerous approaches characterising the radiation field of a water column have been developed and correction attempts for remote sensing data have been applied successfully. Various algorithms describe the complex interaction of biophysical parameters with down- and upwelling radiation in a water body and form the basis for water column correction. Parameters such as varying bottom reflectances and bathymetry aggravate an accurate parameterization of water column correction models. Applying these models, special interest lies in their sensitivity to both quality and accuracy of model input parameters. In this paper we discuss the sensitivity of the water column correction model MIP² to bio-physical parameters, i.e. suspended matters (SM) and chlorophyll (CHL), in case 2 waters.

In August 2010, hyperspectral AISA_eagle data have been acquired; in-situ measurements were conducted concurrently to the airborne campaign. The study was conducted at the rocky shores of the island Helgoland (North Sea, Germany). The study area is characterised by a heterogeneous water body resulting in varying and spatially uncorrelated concentrations of SM and CHL, which aggravate an accurate water column correction.

During analysis, special focus is set on areas with varying water characteristics such as vegetated bedrock, shallow sandy spots and deep water areas. Water column correction is performed using a sub-module of MIP, i.e. WATCOR. Reflectance deviation results show that variations of SM concentrations have a stronger influence than variations of CHL within the water column correction. Whereas, the shallow sandy spots reveal the highest sensitivity at constituent concentration variation followed by the deep water and the vegetated bedrock areas.

Algorithms for retrieving inherent optical properties (IOPs) in coastal waters from remote sensing of water leaving reflectance spectra, are increasingly focused on red and near infrared (NIR) spectral bands, since the simple blue - green ratio approaches, valid in open oceans, fail when in coastal waters with strongly scattering inorganic particles and colored dissolved organic matter (CDOM). NIR spectra can however be significantly impacted by overlapping chlorophyll a fluorescence, and considerable progress has been made to quantify its contribution, and hence achieve more accurate [Chl] retrievals. Recently we have been studying multiangular hyperspectral polarization characteristics of underwater scattered light, using our recently developed Stokes vector polarimeter to fully measure Stokes parameters. From these studies, information on IOPs, in particular the characteristics of non - algal particles (NAP), which are the primary source of underwater polarized elastic scattering, can be obtained. Multiangular hyperspectral polarization measurements, combined with those of IOPs collected in eutrophic waters of Chesapeake/Virginia and New York Harbor/Hudson River areas, showed that chlorophyll a fluorescence markedly impacts (reduces) the underwater degree of polarization (DOP) in the 650 - 700 nm spectral region. By noting the unpolarized nature of algal fluorescence and the partially polarized properties of elastic scattering, we are able to separate the chlorophyll a fluorescence signal from the total reflectance. The analysis is based on comparisons of experimental measurements with vector/scalar radiative transfer computations using measured IOPs as inputs. Relationships between change in observed DOP and fluorescence contributions are examined, and the possibility of using DOP measurements for underwater fluorescence retrieval is evaluated for different scattering geometries.

The range – time optical images [1, 2] of capillary waves using artificial diffuse illumination of water surface like sky illumination was derived in water tank. The software for processing of wave’s images was developed. The technique for recording splashes appearing for strong winds is developed using range – time surface images. The developed method can be used for investigation of free and bounded capillary waves, wave’s breaking, action of internal waves on surface waves [3,4] and scattering of radio and acoustic waves by rough surface in laboratory and natural conditions. The study of gravity-capillary waves in the tank of the IAP RAS was carried out employing the developed optical system with artificial diffuse illumination.

The HY-2A (launched on 2011/8/16) is the first microwave marine remote sensing satellite from HY-2 satellite series developed by China. It includes a dual-frequency altimeter in Ku and C-bands. In this paper, (1) significant wave height (SWH) data from HY-2A altimeter are corrected by using collocated NDBC (U.S. National Data Buoy Centre) buoy data and are compared with Jason-1/2 data; (2) data fusion of SWH from the combination of HY-2A altimeter and other satellite altimeters (Jason-1/2 and Envisat) is given and the results are compared one another; (3) the merged SWH data from HY-2A, Jason-1/2 and Envisat are used to analyze the characteristics of SWH in China Seas and adjacent waters. Comparisons show that the results are good and HY-2A altimetry data work well with other satellite altimetry data.

Satellite high-resolution radar data from Envisat ASAR, RADARSAT-2 and TerraSAR-X sensors are used for the detection and investigation of fine structure of currents and submesoscale eddies. The fine structure of sea currents is manifested in radar images as quasiperiodic slick strips of a horizontal scale from tens of meters to several kilometers. The strips are typically elongated along the currents apparently indicating their jet character and intermittence. The focus is on filamentary slick bands involved into small scale vortical processes and allowing estimation of spatial characteristics of submesoscale eddies based on their SAR signatures. Submesoscale or eddies with diameters of less than Rossby radius of deformation could hardly be investigated by traditional oceanographic means due to spontaneity of their appearance, nonstationarity and short lifetimes. Sources of their generation are still not well known. A large archive of satellite data accumulated during 1999-2011 over different parts of the Black, Baltic and Caspian Seas has been analyzed in order to search, systemize and reveal mechanisms of formation and evolution of small scale eddy structures in these areas. Atmospheric and hydrological fronts and current instability have been found to play a significant role in submesoscale eddies generation. Subsatellite measurements using acoustic Doppler profiler (ADCP) have been performed aimed at verification and adjustment of the results obtained based on satellite radar data. The formation and drift of a near-shore submesoscale anticyclonic eddies of 5-7 km in diameter were observed.

Results of field experiments on radar imaging of surfactant films using satellite SAR (TerraSAR-X) co-located with Xband and Ka-band radar (scatterometer) measurements are described and analyzed. The experiments were performed using surfactant films with pre-measured physical parameters, the surface tension and the film elasticity, at low to moderate wind and at different radar incidence angles. Contrasts characterizing depression of radar backscatter in slicks have been obtained. Theoretical analysis of radar contrasts for low-to-moderate incidence angles has been carried out based on a hydrodynamic model of wind wave damping due to films and on a composite radar imaging model. The hydrodynamic model takes into account wave damping due to viscoelastic films, wind wave generation and a phenomenological term describing nonlinear limitation of the wind wave spectrum. The radar model takes into account Bragg scattering and specular scattering, the latter is usually negligible compared to the Bragg effect at moderate incidence angles (larger than 30-35 degrees), but is obtained to give noticeable contribution to radar backscattering at smaller incidence angles particularly for slick areas when cm-scale ripples is strongly depressed by films. Theoretical calculations of radar contrasts in slicks are compared with experiment.

Complex experiments were performed in the north-eastern part of the Black Sea and in the south-eastern part of the White Sea to study variability of the current fields and other characteristics of the sea, wind waves, and parameters of the near-surface atmospheric layer. Measurements were carried out from the onboard of the scientific research vessels by optical, radar and acoustic sensors. The heterogeneity of bottom topography in Black Sea had quasi-one-dimensional character. The case of the two-dimensionally heterogeneous relief of the bottom was investigated in the White Sea. The peculiarity of these experiments was simultaneous measurements from onboard of vessel synchronously with acquisitions of synthetic aperture radar (SAR) images of the Envisat and TerraSAR-X satellites. We have detected for the case of the quasi-one-dimensionally heterogeneous current a difference between the sea surface roughness above the shelf zone and the roughness at the deep bottom. We found that the inhomogeneities of the bottom topography can manifest as a change not only in the amplitude of different characteristics of surface wave and atmospheric near-water layer, but also in their frequency spectrum. In White Sea the special features of the flow of the powerful tidal current (up to 1 m/s) around the secluded underwater elevation and the spatial structure of surface anomalies in the field of these two-dimensional-heterogeneous currents are analyzed. The numerical simulation of the wind wave transformation in the field of two-dimensional- heterogeneous flows is carried out. The qualitative agreement of the calculation results with the experimental data is shown.

A methodology of cross-comparison of C-band spaceborne scatterometers is developed and applied to ERS-1 and ERS-2 scatterometers data. Assuming the differences between the instruments can be represented by an incidence-angle dependent bias, this paper presents and discusses four methods providing an estimate of that bias and of its standard deviation. These methods use natural distributed targets such as rainforest, ocean and sea ice, and are based on geophysical model functions, namely constant gamma model, CMOD5 and sea ice line model. The backscatter from the natural distributed targets is compared against a simulated backscatter providedby the models. Finally, the deviation of the two datasets from the models are comparedto yield a bias between the two scatterometers. The methodologyis applied to ERS-1 and ERS-2 data acquired during the tandem mission in 1996. Generally, the bias between the ERS-1 and ERS-2 scatterometers is smaller than 0.2 dB over most incidence angles and the four methods provide relatively consistent results. However, in order to achieve a consistent backscatter data, the scatterometers need to be inter-calibrated. The methodology can be useful to cross-calibrate scatterometers on-board other satellites (e.g. METOP, OceanSat-2, HY2A, etc.) in the view of the Global Climate Observing System guidelines.

Detection of oil films and their discrimination from, e.g., biogenic films is a very important ecological problem. Remote sensing methods, particularly, satellite methods are the most perspective for the problem solution. Films in the sea surface optical images can be seen because of changing a) the reflected radiance due to strong depression of short gravity-capillary waves by films and b) the reflection coefficient when considering light reflection from the upper and lower film boundaries. But the effects are strongly determined by film parameters. Natural biogenic films spread down to monomolecular layers and can be characterized by the elasticity and the surface tension coefficient. Oil films have finite thickness and wave damping due to these films is determined by larger number of physical parameters, than biogenic films, namely by the oil density, film thickness, viscosity and elasticity of two film boundaries, etc. Possibilities of filmslick detection and characterization using optical systems of low spatial resolution are analyzed. The threshold values of the film parameters at which film slicks can be detected with these systems are estimated at different observation/illumination conditions and wind regimes. The principal possibility to estimate the film parameters and to identify oil films is demonstrated using a theoretical model. Experimental verification of the model is presented based on measurements of the sea surface radiance contrast in slicks with known film parameters.

An ocean airborne lidar design based on a complex modulated illuminating beam and the received echo signal processing is proposed, which involves the extraction of the modulated component and its matched filtering. A model of this lidar taking into account the effect of surface waves and multiple scattering in water is constructed. The lidar limiting longitudinal and transverse resolutions determined by random light refraction on the surface and scattering in water are estimated.

Sea level anomaly maps from altimeter (AVISO) were retrieved for the Gulf of Cadiz (GoC) for the period 1997-2008, along with maps of Dynamic Atmospheric Correction (DAC), atmospheric pressure at sea level and satellite Sea Surface Temperature (SST). Data were averaged in time to obtain maps of monthly mean time series in order to analyze the seasonal variability of sea level and its main forcing agents along the GoC. Moreover, a very high resolution climatology for the region was combined with the SST maps to explore the steric contribution with enough spatial resolution near the coast. The AVISO sea level anomaly monthly maps were initially de-corrected using the DAC product and then corrected using the inverted barometer method. Atmospheric pressure explained more than 55% of the sea level variance offshore and between 35-45% within the continental shelf. The amplitude of the pressureadjusted sea level semiannual signal was considerably reduced, confirming its meteorological origin. The steric contribution on the pressure-adjusted sea level was addressed by considering local, open ocean, basin-wide and continental shelf steric effects. The open ocean contribution explained the highest percentage of variance all over the basin with the exception of the western shelf, where the best results were obtained with the local contribution. After correcting for the best steric contribution, the amplitude of the remaining offshore annual signal was negligible (0.5-1.0 ± 1 cm). As for the continental shelves, 2- 3 cm (± 0.5-1 cm) of the annual signal remained unexplained, probably due to local effects related with the shelves dynamics.

A global-scale climatological assessment of the temporal and spatial relationships between physical and optical ocean layers was previously performed to determine LIDAR efficiency for measuring the 3D Ocean. That effort provided estimates of laser sensor penetration depth (PD) in the global oceans and identified critical coupling between Mixed Layer Depth (MLD) and Optical Depth (OD) based on potential laser power and ensuing attenuation. We make use of a Bio-Physical ocean model configured for the Gulf of Mexico (GOM) along with remotely sensed satellite measurements to examine LIDAR performance in the Gulf of Mexico coastal regions. The 4Km GOM ocean model runs in near-realtime and produces physical and bio-optical fields which are coupled to in-house derived satellite bio-optical products such as the Diffuse Attenuation Coefficient at 490 nm (Kd490). PD and MLD are coupled to determine laser power efficiency rates across multiple attenuation lengths. The results illustrate the potential utilization of space-borne oceanographic LIDAR to penetrate through the water column, elucidating its applicability for a variety of scientific (characterization of the ocean subsurface layers) and applied (target detection) objectives.

With the wide application of broadband imaging spectrometer in the ocean remote sensor, the depolarizer in front of the optical system must satisfy the high requirement. Based on the character of simple structure and good stability, Lyot depolarizer is widely used in the fiber and grating spectrometer in which the polarization should be controlled strictly. Nowadays the design method of Lyot depolarizer based on the coherent condition is mostly used for laser and sensors of narrow band, not suitable for the broadband and high spectral resolution. According to the theory of matrix optics, the relationship between the residual polarization and the angle and thickness of the depolarizer has been analyzed in the wide wavelength range. The formula is too complicated to get an analysis solver. With the numerical results, as the wedge angle increasing the residual polarization dying oscillates to a stable value. As the crystal thickness increasing the value of residual polarization is oscillating to zero. As a result, increasing the wedge angle and the thickness both could reduce the residual polarization of the depolarizer, but considering the dimension and the resolution of the optical system the wedge angle and the thickness of the depolarizer have restrictions. The design process of Lyot depolarizer used for broadband are summarized as follows: 1. Using the numerical solution the variability of the residual polarization along the wedge angle and thickness are analyzed; 2. According to the requirement of the spectral resolution the wedge angle could be chosen; 3. While the wedge angle is curtained, based on the numerical results the suitable thickness could be solved satisfying the requirement of the residual polarization. This method can be widely applied to the depolarizer design in imaging spectrometer of broadband which can cover several hundred nanometers and high spectral resolution which is to several nanometers. In this article a Lyot depolarizer has been designed for a broadband imaging spectrometer used in ocean observation. In the wavelength from 400nm to 950nm, the residual polarizations of the depolarizer are less than 2%. This is necessary for the instrument to obtain the accurate radiance data of the target.

The vertical profiles of beam attenuation coefficient (c) can provide information about the distribution and variability of suspended particles in the water column. Vertical profiles of particulate beam attenuation coefficient at 660 nm (c_p(660)), Chlorophyll a (chla) and Particulate Organic Carbon(POC) were analyzed to examine patterns and controlling factors of vertical distributions in the East China Sea (ECS), based on two cruises in summer and late autumn. In late autumn, the c_p(660) profiles showed uniform distribution with depth in most of shelf regions, and high value of c_p(660) was observed in some inshore stations caused by strong resuspension. In summer, c_p(660) exhibited weak subsurface maxima phenomenon in outer shelf, while with the well vertical mixed structures in the northern coast areas of ECS. The variability of c_p(660) between summer and autumn were mainly influenced by the changes of thermocline distribution in the ECS. In the late autumn, water potential density were characterized as fully vertical mixed, on the contrary, the strong stratifications of water column were observed in summer. Except for several inshore stations with highly influenced by terrestrial input, significant relationships between POC and c_P(660) were observed in both late autumn and summer. The close relationship between POC and c_p(660) could be an potential application to retrieve the POC profiles from in situ c_P(660) measurements, and be applied to the surface POC estimated from space.

The East China Sea (ECS) is the 11th largest marginal seas around the world. ECS has widely continental shelf, and has relatively high concentration of suspended particulate matter (TSM) affected by the terrestrial material from the large rivers, including the Changjiang River, and also affected by the resuspension in the winter. Recently, several regional algorithms for the TSM retrieval in the ECS have been proposed, such as the algorithms developed by Zhang et al. (2010) and Han et al. (2006). Due to the variation of the optical properties of TSM, it is significant to study whether existing algorithms are adequate and reliable for the inversion of the concentration of TSM in the ECS for all seasons. Yet, up to now, the validation of the satellite retrieved TSM is still lack due to the insufficient of the in-situ data and the standard TSM product in the ECS. In the past three years, we have carried out four seasonal cruises covering the whole ECS, including the spring cruise from May to June 2011, the summer cruise in August 2009, the autumn cruise from November to December 2010, and the winter cruise from December 2009 to January 2010. In this paper, we firstly analyzed the spatial-temporal distribution of the TSM in the ECS. The results showed that there was remarkable seasonal variation with higher concentration in the winter half year and lower concentration in the summer half year. The concentration of TSM was higher inshore than that of offshore. The isolines were parallel to the shoreline as a whole. There was a turbid water tongue with notably seasonal variation spreading to southeast at the 29°N in the middle of the ECS. Finally, based on the remote sensing reflectance retrieved by the Aqua-MODIS and SeaWiFS data, the performance of the four inversion algorithms of TSM were evaluated using the in-situ measured TSM data in the ECS, including the Clark’s model in the SeaDAS, Zhang’s model, Han’s model and Tassan’s model. The results show that all of the TSM retrieved by the four models have large error as compared with the in-situ data, indicating the strong requirement of the improving the TSM retrieval in the ECS.

Directional ocean wave spectra can describe the energy distribution of ocean wave and play an important role in oceanography. Synthetic aperture radar (SAR) can measure wave spectra based on a nonlinear mapping model between the image spectra (or cross spectra) and wave spectra. Due to the complexity of variable estimation and wave number cut off in azimuth direction in the mapping process, some scientists have been endeavoring to improve the retrieval of wave spectra. The paper proposes a method for the retrieval, which don’t depend on any external information except wind direction. It separates into two parts. In part 1, the spectra for real image or the cross spectra for complex image are calculated. And the modulation transfer function (MTF) is estimated including real aperture radar (RAR) MTF and velocity bunching. Then the wave spectra are retrieved by direct dividing based on the quasi-linear relation. The 180° ambiguity is removed from the imaginary part of cross spectra or the wind direction. The significant wave height (Hs), peak wave wavelength (L) and peak wave direction (D) are extracted from the retrieval. If the angle between the D and the azimuth direction is higher than 45°, the retrieval is finished. If the angle is lower than 45°, we go on retrieving. In part 2, the first guess spectra are needed to compensate the lost wave information, which can be parametrically constructed based on the retrieved wave spectra in part 1. Finally the wave spectra are iteratively retrieved from the first guess spectra based on the nonlinear relation. The Envisat ASAR images are used to validate the method. In case 1, the RMSE between this method and SARTool on D, L, Hs is 7.6°, 19.7 m, 0.18 m respectively. In case 2, the RMSE between this method and Jason-1 on Hs is 0.5 m.

At present, there are two types of method to detect ships in SAR images. One is a direct detection type, detecting ships directly. The other is an indirect detection type. That is, it firstly detects ship wakes, and then seeks ships around wakes. The two types all effect by speckle noise. In order to improve the accuracy of ship detection and get accurate ship and ship wakes parameters, such as ship length, ship width, ship area, the angle of ship wakes and ship outline from SAR images, it is extremely necessary to remove speckle noise in SAR images before data used in various SAR images ship detection. The use of speckle noise reduction filter depends on the specification for a particular application. Some common filters are widely used in speckle noise reduction, such as the mean filter, the median filter, the lee filter, the enhanced lee filter, the Kuan filter, the frost filter, the enhanced frost filter and gamma filter, but these filters represent some disadvantages in SAR image ship detection because of the various types of ship. Therefore, a mathematical function known as the wavelet transform and multi-resolution analysis were used to localize an SAR ocean image into different frequency components or useful subbands, and effectively reduce the speckle in the subbands according to the local statistics within the bands. Finally, the analysis of the statistical results are presented, which demonstrates the advantages and disadvantages of using wavelet shrinkage techniques over standard speckle filters.

The variations of Dissolved Oxygen (DO) in the near-bottom waters off the Changjiang (Yangtze River) Estuary before and after the passage of typhoons are investigated using both remotely sensed and in situ data sets. The Ekman pumping velocity during and after Typhoon was calculated. From buoys observation, typhoon passed by cause the water exchange between upper and lower layer. The mixture made the Dissolved Oxygen (DO) level changed to high level in short time. The level of DO at 50 m increased from 3.2 to 6.2 during the period of strong winds (< 30 knots) of Typhoon Muifa. The mixing process occurred in a short time, about 1-2 hours. The raise and resume result also has been verified from cruise observations. Typhoon effects hypoxia in many aspects. Typhoon can affect hypoxia in many ways. SST decreases as typhoon passes directly over the water. The concentrations of surface Chl a increase gradually due to mixing triggered by the typhoon. The affected area and time of change of hypoxia depend on the wind speed and the movement of the typhoon as well as the water depth.

A total of 12 years (2000–2011) of sea surface wind data from QuikSCAT and ASCAT are employed to examine the seasonal and interannual variability over the China Seas and its adjacent ocean. The wind speed and direction, strong wind frequency, monsoon onset and transition time are revealed by statistic analysis. The result shows that (1) the wind speed is highest in winter and lowest in summer in the study area. The Southeastern Vietnam, Luzon Strait, Taiwan Strait and the eastern ocean of Japan are the regions with the higher wind speed throughout the year, especially more than 12 m/s in winter. (2) The monsoon prevails in the China Seas, southwesterly in summer and northeasterly in winter, while southeast wind also occurs all the seasons except winter. The northwest wind only occurs in the north of 27°N in winter. (3)The strong wind more than 10.8 m/s exceeds 140 days per year in the Taiwan Strait while only 30 days in the Bohai Sea and Yellow Sea. In addition, the Luzon Strait can reach 120 days with strong wind larger than 10.8 m/s, ranking the second after the Taiwan Strait. (4) The time of monsoon onset changes from year to year. Generally, the southwest wind in the low latitudes begins in May and ends in September or October, then turns to northwest wind completely which almost have no transition time. For the mid-latitudes zone, the southwest wind begins in June and ends in August. May and September are the transition time. Then the northeast wind begins to prevail. (5) The trend of sea surface wind speed in the study area is increasing from 2000 to 2011, except the Southeastern Vietnam. The annual mean wind speed is lowest in 2002 and 2010 during the period of. 2000–2011

Red tide not only destroys marine fishery production, deteriorates the marine environment, affects coastal tourist industry, but also causes human poison, even death by eating toxic seafood contaminated by red tide organisms. Remote sensing technology has the characteristics of large-scale, synchronized, rapid monitoring, so it is one of the most important and most effective means of red tide monitoring. This paper selects the high frequency red tides areas of the East China Sea as study area, MODIS/Aqua L2 data as the data source, analysis and compares the spectral differences in the red tide water bodies and non-red tide water bodies of many historical events. Based on the spectral differences, this paper develops the algorithm of Rrs555/Rrs488> 1.5 to extract the red tide information. Apply the algorithm on red tide event happened in the East China Sea on May 28, 2009 to extract the information of red tide, and found that the method can determine effectively the location of the occurrence of red tide; there is a good corresponding relationship between red tide extraction result and chlorophyll a concentration extracted by remote sensing, shows that these algorithm can determine effectively the location and extract the red tide information.

In this article, EOS MODIS ocean color and sea-surface temperature data were used to study the influence of coastal upwelling on a red tide in the Zhejiang Coastal Waters in the summer of 2007. Several cloud-free and date-continued ocean color and sea-surface temperature images during the red tide event were selected and processed in this study. According to the field observations of the red tide, pixels with chlorophyll concentration higher than a certain value were considered as the red tide waters in the ocean color images. And the coastal upwelling in the Zhejiang Coastal Waters was measured by applying a temperature threshold approach from the sea-surface temperature images. Then, the temporal and spatial distributions of the red tide and the coastal upwelling were contrastively analyzed. Results show that there exists a high degree of correlation in spatial distribution between the coastal upwelling and the red tide. The coastal upwelling affects the spatial cover of the red tide according to their spatial correlation and the upwelling plays a crucial role in the development of the red tide in term of water temperature. The upwelling in the Zhejiang Coastal Waters is an important dynamic factor for the formation of red tides there.

This article utilized aerosol product of MODIS and aerosol data provided by AERONET which is real-time monitoring data about aerosol in a station to study spatial-temporal changes of aerosol in the Yellow Sea of China in 2006, and adopted some indexes such AOD (Aerosol Optical Depth) and Angstrom index (α and β), and analyzed monthly distribution and annual average of aerosol. The result suggested that AOD had significant negative correlation with Angstrom-α (r=-0.7261), and significant positive correlation with Angstrom-β (r=0.9576), and Angstrom-α had significant negative correlation with Angstrom-β (r=-0.8791). AOD and Angstrom-β came up to the maximum in Spring, then in Summer and Winter, and down to the minimum in Fall in the study area, and Angstrom-α was completely opposite. AOD and Angstrom-β had a upward trend from offshore to deep sea area, and from the north to the south of the Yellow Sea, while Angstrom-α had a downward trend. Analysis of Angstrom-α displayed that the offshore was polluted by small particles from anthropic activities, and the main content of aerosol was large particle of sea salt in the deep sea field. The main type of aerosol was consisted of small particle aerosol emitted from anthropic activities in Summer and Fall, and of sea-salt particle in Spring and Winter in the Yellow Sea. Spatially the diameter of aerosol in the north of the sea was bigger than one in the south. This study obtained the general distribution spatially and temporally in the Yellow Sea of China, and especially the fact that the main content of aerosol in the offshore was small particle from anthropic activities was paid attention to

Remote sensing imagery was collected from a low flying aircraft along the near coastal waters of the Florida Panhandle and northern Gulf of Mexico and into Barataria Bay, Louisiana, USA, during March 2011. Imagery was acquired from an aircraft that simultaneously collected traditional photogrammetric film imagery, digital video, digital still images, and digital hyperspectral imagery. The original purpose of the project was to collect airborne imagery to support assessment of weathered oil in littoral areas influenced by the Deepwater Horizon oil and gas spill that occurred during the spring and summer of 2010. This paper describes the data acquired and presents information that demonstrates the utility of small spatial scale imagery to detect the presence of weathered oil along littoral areas in the northern Gulf of Mexico. Flight tracks and examples of imagery collected are presented and methods used to plan and acquire the imagery are described. Results suggest weathered oil in littoral areas after the spill was contained at the source.

CZMIL is an integrated lidar-imagery sensor system and software suite designed for the highly automated generation of physical and environmental information products for mapping the coastal zone. This paper presents the results of CZMIL system validation in turbid water conditions on the Gulf Coast of Mississippi and in relatively clear water conditions in Florida in late spring 2012. The system performance test shows that CZMIL successfully achieved 7-8m depth in K_d =0.46m^-1 (K_d is the diffuse attenuation coefficient) in Mississippi and up to 41m when K_d=0.11m^-1 in Florida. With a seven segment array for topographic mode and the shallow water zone, CZMIL generated high resolution products with a maximum pulse rate of 70 kHz, and with 10 kHz in the deep water zone. Diffuse attenuation coefficient, bottom reflectance and other environmental parameters for the whole multi km² area were estimated based on fusion of lidar and CASI-1500 hyperspectral camera data.

Hyperspectral imagery offers unique benefits for detection of land and water features due to the information contained in reflectance signatures such as the bi-directional reflectance distribution function or BRDF. The reflectance signature directly shows the relative absorption and backscattering features of targets. These features can be very useful in shoreline monitoring or surveillance applications, for example to detect weathered oil. In real-time detection applications, processing of hyperspectral data can be an important tool and Optimal band selection is thus important in real time applications in order to select the essential bands using the absorption and backscatter information. In the present paper, band selection is based upon the optimization of target detection using contrast algorithms. The common definition of the contrast (using only one band out of all possible combinations available within a hyperspectral image) is generalized in order to consider all the possible combinations of wavelength dependent contrasts using hyperspectral images. The inflection (defined here as an approximation of the second derivative) is also used in order to enhance the variations in the reflectance spectra as well as in the contrast spectrua in order to assist in optimal band selection. The results of the selection in term of target detection (false alarms and missed detection) are also compared with a previous method to perform feature detection, namely the matched filter. In this paper, imagery is acquired using a pushbroom hyperspectral sensor mounted at the bow of a small vessel. The sensor is mechanically rotated using an optical rotation stage. This opto-mechanical scanning system produces hyperspectral images with pixel sizes on the order of mm to cm scales, depending upon the distance between the sensor and the shoreline being monitored. The motion of the platform during the acquisition induces distortions in the collected HSI imagery. It is therefore necessary to apply a motion correction to the imagery. In this paper, imagery is corrected for the pitching motion of a vessel, which causes most of the deformation when the vessel is anchored at 2 points (bow and stern) during the acquisition of the hyperspectral imagry.