“O Mar Está para Peixes?” – an Interactive Platform for Open Source Fishery Data in Rio De Janeiro State

Despite the wide dissemination of information access, open data scarcity in fisheries science is still seen as a challenge. Thus, initiatives such as Sea Around Us and Fish Stats stand out. Particularly in developing countries, fishery data collection systems are precarious and there is a lack of national platforms to make fisheries data available. In Brazil, some states such as São Paulo and Santa Catarina have their own data repositories in web platforms, but there are limitations for dynamic queries. In addition, fisheries management based on the “Ecosystem Approach to Fisheries” (EAF) have been discussed and adopted, and environmental variables have been used as indicators to increase the robustness of fishery models. In this sense, the present work proposes a fishery data compilation platform named O mar está para peixes? (Are there fish in the sea?), which contains fishery data and fishery-related satellite remote sensing data (i.e. sea surface temperature, chlorophyll concentration) for the State of Rio de Janeiro, Brazil. The platform is divided in five sections: Fishery, Habitat, Map, Satellite and Download. These sections make data available for dynamic and  personalized consultations, with the option of downloading the data. A standard spreadsheet developed for users to submit their own data is  presented, with the goal of promoting participation and the collective  construction of the platform. This is a new step towards the development of  an EAF in Rio de Janeiro, which will potentially open the pathway for the  integration of public agencies, research institutions, fishing industry and artisanal fishermen

Comparação de técnicas de eliminação do efeito striping para imagens CCD CBERS-2B

The striping effect is a common type of noise presented in some remote sensing systems. In most of times, it is caused by poor relative calibration between detectors. Striping not only affects the quality and image interpretation but also compromise image processing. Some proposals have sought to correct this kind of effect. Among them we can mention the digital filters based on statistical operations, and filters based on Fourier transform. This study compared four filters, been tree statistical and one based on Fourier transform, named: the median filter, the multilevel median filter, the moment matching filter, and the one based on Fourier transform. Each filter was applied to all CCD sensor spectral bands from CBERS-2B (China Brazil Earth Resource Satellite). A visual interpretation was made in order to compare the four filter tested. Results showed that each band had a specific filter that better corrects their striping effect. The main problem in this case of noise correction was finding the best compromise between noise elimination and spatial resolution degradation, which creates the blurring effect. Filters have also shown not to vary drastically image mean and standard deviation which leads to just a small changing on image histogram.Pages: 2661-266

Realce de imagens CCD CBERS–2B com filtros multiescala ótimos ponderados

A feature of images generated by CCD CBERS-2B is the blurred appearance and also they show a very intense noise stripes in almost all bands, making it difficult to obtain information and to analyze the content present in these images. Enhancement strategies using traditional high-pass filtering not only enhance the features, but also the noise present in images. In this study we sought to improve these images initially decreasing noise stripes using the Fourier transform filter and the median and then highlighting the features using high-pass filters and low-pass as weights from a multiscale decomposition. To automate the process the optimum enhancement is obtained as a linear combination of elements of the set of weights defined by the outputs of the wavelet transform using minimum squares. The method is compared with the method of Richardson-Lucy, showing that it is possible to enhance with a quality equivalent and even superior because it takes a smaller amplification of noise in the image.Pages: 2561-256

Ajuste de bandas de modelos empíricos de estimativa de clorofila aplicados à região da planície de inundação do Lago Grande Curuai - PA

Empirical Models to estimate chlorophyll-a concentrations are among the most used in the remote sensing community. Historically, those models were applied to ocean monitoring, but in the last decade they were tested for Case II water types studies. In particular, in tropical water bodies characterized by highly complex mixture of optically active components. This complexity, based on high concentration of colored dissolved Organic Matter (CDOM), Total of Suspended Sediments (TSS) and Chlorophyll- (Chlo-a) that varies independently, one from each other, makes it necessary the search for a set of spectral bands able to improve the accuracy of chlorophyll estimates. This work uses a computational search method to find the best band set, for 295 samples distributed in 4 periods in a hydrological cycle. The samples are from the Curuai floodplain located in the Pará State in the Amazon Region. Results show good agreement to literature, but also shows some discrepancies, mostly because of tropical waters complexity. The new bands show better adjustments compared to standard bands intervals, found in literature. Models of Two and three band are adequate only for two periods with high degree of confidence. A discussion about the behavior of each period, and its empirical model best fit is also made.Pages: 8924-893

Simulação e Restauração de Imagens HRC CBERS 2B

Restoration is an image processing technique for correcting distortions inserted by sensor systems during the imaging process. Blurring is one of the most notable effects, which reduce the amount of information on the image. There are several restoration techniques presented in literature. However, the application of such filters depends intrinsically on the type of sensor, which leads to a comparison between techniques, in order to find the method that better fits the proposed sensor. An alternative for a comparison is image simulation. Through image simulation techniques it is possible to estimate characteristics from existing or planned sensors, enabling an assessment sensors performance or the quality of image processing techniques applied to these images. This work proposes the comparison of three restoration methods applied to HRC (High Resolution Camera) sensor, from, CBERS 2B (China Brazil Earth Resource Satellite) satellite: Wiener filter, Richardson- Lucy filter and Modified Inverse Filter. For the comparison, an image from HRC - CBERS 2B sensor is simulated using PRISM (Panchromatic Remote-sensing Instrument Mapping) sensor from ALOS (Advanced Land Observing System) satellite as input. Statistical measures show that Richardson-Lucy method outperforms the other two methods. Visual results of the simulation and restoration are also shown.Pages: 2652-266

Atenuação vertical da irradiância descendente na coluna de água e sua influência sobre a ocorrência de macrófitas submersas - Reservatório de Nova Avanhandava

Submerged macrophytes are a serious problem in water reservoirs. The radiation availability is among the main factors related with the occurrence of this vegetation. Therefore, this study aimed to survey the vertical attenuation for downward irradiance and their influence on submerged macrophytes occurrence. The work was made in a region of Tietê river arm, in Nova Avanhandava reservoir. Data about the river depth and plant height were collected using an echosounder BioSonics DT-X. Downward irradiance data were collected in different depths using TriOS Optical sensor. It was noted that the downward irradiance decreases exponentially with depth. The vertical attenuation coefficient and the euphotic zone depth were calculated. Therefore, the behavior of submerged aquatic vegetation with different radiations quantities was evaluated. Up to 1 meter depth submerged macrophytes had not a strong development. It happened due to excessive radiation and waves. Between 1 and 5 meter the macrophytes height increase with the depth. Between 5 and 8 meter the macrophytes are highest because the lower light intensities make the higher elongation of the occurred species (E. densa and E. najas). To leave the euphotic zone (9,7 meter) the submerged aquatic vegetation occurrence is completely interrupted. Finally, the study of vertical attenuation for downward irradiance in the water column can contribute to the understanding of the behavior of submerged aquatic vegetation in different aquatic environments.Pages: 5792-579

AlgaeMAp: Algae Bloom Monitoring Application for Inland Waters in Latin America

Due to increasing algae bloom occurrence and water degradation on a global scale, there is a demand for water quality monitoring systems based on remote sensing imagery. This paper describes the scientific, theoretical, and methodological background for creating a cloud-computing interface on Google Earth Engine (GEE) which allows end-users to access algae bloom related products with high spatial (30 m) and temporal (~5 day) resolution. The proposed methodology uses Sentinel-2 images corrected for atmospheric and sun-glint effects to generate an image collection of the Normalized Difference Chlorophyll-a Index (NDCI) for the entire time-series. NDCI is used to estimate both Chl-a concentration, based on a non-linear fitting model, and Trophic State Index (TSI), based on a tree-decision model classification into five classes. Once the Chl-a and TSI algorithms had been calibrated and validated they were implemented in GEE as an Earth Engine App, entitled Algae Bloom Monitoring Application (AlgaeMAp). AlgaeMAp is the first online platform built within the GEE platform that offers high spatial resolution of water quality parameters. The App benefits from the huge processing capability of GEE that allows any user with internet access to easily extract detailed spatial (30 m) and long temporal Chl-a and TSI information (from August 2015 and with images every 5 days) throughout the most important reservoirs in the State of São Paulo/Brazil. The application will be adapted to extend to other relevant areas in Latin America

Simulação de uma imagem WFI/CBERS-3 para a classificação de massas d’água no Reservatório de Ibitinga – SP

Even though currently there are a lot of sensors with adequate spectral and radiometric resolutions and field of view to the water properties characterization, the low spatial resolution limits the application of their images on the inland water study. The WFI sensor that will be launched at the CBERS-3 satellite may fill this gap by having spectral, radiometric and spatial characteristics that attend the application needs for inland water studies. To assess a sensor performance before its launch there are available image simulation methods. This article aimed to assess the potential of a WFI/CBERS-3 image to distinguish optically distinct water masses in the Ibitinga ReservoirSP. Therefore, it was accomplished the image simulation of this sensor from a QuickBird scene, which has similar spectral and radiometric properties to the WFI sensor. Unsupervised classifications were performed with different numbers of spectral classes for the simulated image and for a TM/Landsat-5 image (resampled to the same pixel size). It was realized that the application of high radiometric resolution images allows the obtaining of better results for the optically distinct water masses classification. However, the use of high spatial resolution images on the simulation process may complicate the water masses distinction due to the direct surface reflection of the Sun light. The surface water ripples caused by the wind action intensify the brightness in these images, damaging the classification. Nevertheless, the WFI/CBERS-3 image simulation indicated a high potential of this sensor to water quality studies in inland aquatic systems.Pages: 2530-253