We provide comparison results and detailed data analyses for evaluating performance of various sun glint models for satellite ocean color data processing. Osa exploring the limits for sky and sun glint correction. Uav, hotspot, sun glint, image preprocessing, photogrammetry, remote sensing, flight planning and control, software development, chemical technology, tp11185. Simulation and smap observation of sunglint over the land. Unfortunately, the problem of sun glint is particularly acute under conditions at which remote sensing might otherwise be most effective. These results validate the claim that the dolp in the glint region is independent of the wind speed and is that predicted by the.
Simple and robust removal of sun glint for mapping shallowwater benthos. In most cases, sun glint contaminated pixels are directly masked and excluded from the data analysis 24. A sun glint correction method for hyperspectral imagery. The dotted lines represent the dolp predicted by the fresnel equations, and star symbols in the top plot mark the direction of specular re.
Sun glint correction of high and low spatial resolution. There are a number of methods used for sun glint removal. Pdf removing sun glint from optical remote sensing images. The polymer and pcabased algorithms yield imagery that is comparable with standard imagery. Principles of remote sensing detection and discrimination of objects or surface features means detecting. The bidirectional reflection of downwelling light at the ocean surface is computed using the empirical relationship between surface wind field and the slope distribution of wave facets derived by cox and munk 1954a. Request pdf impact of sun glint on salinity remote sensing. Simultaneous estimation of the refractive index and thickness. A spectral model for correcting sun glint and sky glint. Removing sun glint from optical remote sensing images of shallow. We used the red sea model to tune the standard chlorophyllalgorithms and the overestimation in chlorophylloriginally observed was corrected. There are usually no meaningful retrievals in regions significantly contaminated by sun glint. Sun glint, the specular reflection of light from water surfaces, is a serious confounding factor for remote sensing of water column properties and benthos. Sun glint occurs in imagery when the water surface orientation is such.
Spatial profiles of pixel radiance by pixel position were compared and slope values were calculated. Evaluation of sun glint correction algorithms for high. The sensors in this example are the two types of photosensitive cells, known as the cones and the rods, at the retina of the eyes. While the weibull pdf accurately parameterizes windspeed pdf over much.
The glint model performance is then evaluated by comparing the modisderived sun glint reflectances with glint reflectance predicted by various models. The use of remote sensing techniques is increasing rapidly, finding new fields of application as technology advances in. Pdf removing sun glint from optical remote sensing images of. Using remote sensing to detect the polarized sunglint reflected. Jan 17, 2014 ocean colour remote sensing has supported research on subjects ranging from marine ecosystems to climate change for almost 35 years. Using remote sensing to detect the polarized sunglint reflected from. About cookies, including instructions on how to turn off cookies if you wish to do so. Characterization of sun and sky glint from wind ruffled sea. Atmospheric correction of satellite ocean color imagery in. By continuing to browse this site you agree to us using cookies as described in about cookies. The use of remote sensing techniques is increasing rapidly, finding new fields of application as technology advances in developing the remote sensing systems.
Oct, 2016 sun glint is the specular reflection of light from the water surface, which often causes unusually bright pixel values that can dominate fluvial remote sensing imagery and obscure the water. Automatic sun glint removal of multispectral highresolution. Removing sun glint from optical remote sensing images of shallow rivers. Removing sun glint from river imagery article pdf available in earth surface processes and landforms october 2016 with. Estimation of the sunglint radiance field from optical satellite imagery. Remote sensing is the common name for all methods used to collect data at a distance from the object under study by some kind of recording device. Removing sun glint from optical remote sensing images of. Modeling and application of multispectral oceanic sun glint. The traditional technique based on the single horizontal linear polarizer was a common method to reduce the sun glint by eliminating its spolarized component, nevertheless, the residual ppolarized component could be still too strong to saturate the detector in some cases. Dec 17, 2015 thus, the objective of this study is to determine the sun glint threshold required for detecting thin oil films in optical remote sensing imagery. A new simple concept for ocean colour remote sensing using. Thus, the objective of this study is to determine the sun glint threshold required for detecting thin oil.
This problem was recently overcome by hochberg et al. Remote sensing of sun induced chlorophyll fluorescence. Sun glint has high impact on several kinds of remote sensing applications over oceans, e. Remote sensing measurements represented as a series of digital numbers the larger this number, the higher the radiometric resolution, and the sharper the imagery spectral bands and resolution for various sensors cimss. Osa correction of sun glint contamination on the seawifs. Sun glint correction algorithms were tested on a hyperspectral image containing crosstrack sun glint. Thus, the objective of this study is to determine the sun glint threshold required for detecting thin oil films in optical remote sensing imagery. In traditional remote sensing of ocean color, glint mitigation is achieved.
For remote sensing of the ocean and atmosphere optical properties, the measurement of radiances affected by sun glint has to be avoided andor masked out. In optical remote sensing imagery, the contrast between surface oil and nonoil water comes from two sources. Remote sensing of sun induced chlorophyll fluorescence msc thesis by thomas c. Sun glint and sea surface salinity remote sensing emrnanuel p. The sun glint problem is a major issue to be addressed for mwir marine targets detection. Whereas the systems where the remote sensing measurements depend upon the external energy source, such as sun are referred to as passive remote sensing systems. Here we investigate to what extent information about sun glint can be derived from spectrally resolved. This is achieved through comparing sameday usually within 12h imagery of multiple sensors over the same natural seeps. Oct 15, 2017 the sun glint effect is produced in specular surfaces such as water, glass or metal when the angle of incidence of the sun equals the angle of reflection, whereas the hotspot effect is produced due to a direct alignment between the sun, the camera and the position on the ground, that is, the point on the ground opposite the sun in relation to. The seaviewing wide fieldofview sensor seawifs is capable of operationally tilting the sensor 20 away from nadir to minimize sun glint.
Evaluation of sun glint models using modis measurements. Sunglint has high impact on several kinds of remote sensing applications over oceans, e. Introduction satellite and airborne remote sensing are important means for ocean monitoring. Typically, sun glint forms bands of white along wave edges on the windward side of near shore. Remote sensing of environment volume 1, issue 10, october 2009, pages 22672274 a sun glint correction method for hyperspectral imagery containing areas with non. A spectral model for correcting sun glint and sky glint core.
Pdf sun glint is the specular reflection of light from the water surface, which often causes unusually bright pixel values that can dominate fluvial. To address this issue, the hyspiri sun glint subgroup was formed during the fall of. Remote sensing methods to study spatial and temporal changes in water quality using satellite or aerial imagery are limited by the inherently low re. Results suggest that the overestimation was likely due to an excess of cdom absorption. Sun glint and sea surface salinity remote sensing emmanuel p. Sunglint in current smos brightness temperature will be a few times stronger than that in 2006. Here we investigate to what extent information about sunglint can be derived from spectrally resolved. Atmospheric correction of satellite oceancolor imagery can be performed through thin clouds and in the presence of sun glint, and in the vicinity of clouds, sea ice, and land. Inundation discriminated using sun glint geoscience and. Remote sensing of environment university of maine system. Sun glint is the specular reflection of light from the water surface, which often causes unusually bright pixel values that can dominate fluvial remote sensing imagery and obscure the water.
Their measurements gave a pdf that was approximately gaussian, and they. To demonstrate the effectiveness of ppr in diminishing sun glint, we simulated the upward stokes vector at the toa using the vector radiative transfer. The negative effects of sun glint in remote sensing of rivers are. An example with the aquarius radiometer the aquariussacd mission will employ three lband 1. Sun glint requirement for the remote detection of surface oil. The sun glint effect is produced in specular surfaces such as water, glass or metal when the angle of incidence of the sun equals the angle of reflection, whereas the hotspot effect is produced due to a direct alignment between the sun, the camera and the position on the ground, that is, the point on the ground opposite the sun in relation to. Visual remote sensing system the human visual system is an example of a remote sensing system in the general sense. Correlation values were calculated for each spectral comparison and averaged for each sun glint correction algorithm. Sun glint correction of high and low spatial resolution images of. Target detection in sun glint using the improved mwir. Sunglint produces radiance that can far exceed the radiance scattered by both the. Ocean colour remote sensing has supported research on subjects ranging from marine ecosystems to climate change for almost 35 years. Remote sensing of environment volume 1, issue 10, october 2009, pages 22672274 a sun glint correction method for hyperspectral imagery containing areas with nonnegligible water leaving nir signal. One commonly adopted by the aquatic remote sensing community is the one developed by.
Although sun glint is ubiquitous in fluvial remote sensing imagery, riverspecific methods for. Remote sensing of suninduced chlorophyll fluorescence msc thesis by thomas c. A method is proposed to use the oceanic sun glint for remote sensing applications. Simultaneous estimation of the refractive index and. Remote sensing of coastal areas requires multispectral satellite images with a high spatial. Le vine instrumentation sciences branch goddard space flight center greenbelt, md 20771 popular summary a new mission in space, called aquariussacd, is being built to measure the salinity of the worlds oceans.
714 279 845 836 244 918 1304 513 739 1188 1587 1354 233 1499 1157 402 1557 976 242 1111 940 607 32 981 218 94 303 196 699 1314 376 352 915 937