Coupling remote sensing data with crop model has been shown to improve accuracy of the model yield estimation.
MOSICAS model simulates sugarcane yield in controlled conditions plot, based on different variables, including the
interception efficiency index (i). In this paper, we assessed the use of remote sensing data to sugarcane growth modeling by 1) comparing the sugarcane yield simulated with and without satellite data integration in the model, and 2) comparing two approaches of satellite data forcing. The forcing variable is the interception efficiency index (Εi). The yield simulations are evaluated on a data set of cane biomass measured on four on-farm fields, over three years, in Reunion Island. Satellite data are derived from a SPOT 10 m resolution time series acquired during the same period. Three types of simulations have been made: a raw simulation (where the only input data are daily precipitations, daily temperatures and daily global radiations), a partial forcing coupling method (where MOSICAS computed values of Εi have been replaced by NDVI computed Εi for each available satellite image), and complete forcing method (where all MOSICAS simulated Εi have been replaced by NDVI computed Εi). Results showed significant improvements of the yield's estimation with complete forcing approach (with an estimation of the yield 8.3 % superior to the observed yield), but minimal differences between the yields computed with raw simulations and those computed with partial forcing approach (with a mean overestimation of respectively 34.7 and 35.4 %). Several enhancements can be made, especially by optimizing MOSICAS parameters, or by using other remote sensing index, like NDWI.
We present data collected as part of ValHyBio- VALidation HYperspectral of a BIOgeochemical model in
the South Western Tropical Lagoon of New Caledonia, a PNTS-sponsored program dedicated to chlorophyll satellite
imaging and validation as affected by bathymetry. The specific goals of ValHyBio are to: - examine time-dependent
oceanic reflectance in relation to dynamic surface processes, - construct field/satellite reflectance-based chlorophyll
models, - investigate the feasibility of inverting the model to yield surface chlorophyll and turbidity, - validate the
biogeochemical model with field/satellite observations. In situ bio-optical parameters include absorption coefficients
by CDOM and particles, Secchi disk depth, backscattering coefficient, pigment concentration, suspended matter
concentration, and K_dPAR. They are measured every month at 5 stations, of contrasted bathymetry and bottom
reflectance, as well as at a reference station situated 4 miles offshore, and on a station over coral reefs. Remote sensing
reflectance is calculated from the absorption and backscattering coefficients and compared with satellite data.
SeaWIFS and MODIS AQUA match-ups collected over the period 1997-2010 (ValHySat-VALidation HYperspectral
SATellite database) are used. Satellite retrievals are examined as a function of bathymetry. The feasibility of a longterm
monitoring program of optical water retrieval with satellite remote sensing technique is examined in the frame of
the GOPS (South Pacific Integrated Observatory).
Ship detection from remote sensing imagery is a crucial application for maritime security which includes among others
traffic surveillance, protection against illegal fisheries, oil discharge control and sea pollution monitoring. In the
framework of a European integrated project GMES-Security/LIMES, we developed an operational ship detection
algorithm using high spatial resolution optical imagery to complement existing regulations, in particular the fishing
control system. The automatic detection model is based on statistical methods, mathematical morphology and other
signal processing techniques such as the wavelet analysis and Radon transform. This paper presents current progress
made on the detection model and describes the prototype designed to classify small targets. The prototype was tested on
panchromatic SPOT 5 imagery taking into account the environmental and fishing context in French Guiana. In terms of
automatic detection of small ship targets, the proposed algorithm performs well. Its advantages are manifold: it is simple
and robust, but most of all, it is efficient and fast, which is a crucial point in performance evaluation of advanced ship
Tropical oligotrophic coral reef lagoons are areas of high biodiversity. Chlorophyll concentration, a proxy for
phytoplankton biomass and primary production, is useful to monitor the carbon balance in the context of the climate
change and to validate simulations by coupled biogeochemical models. Chlorophyll monitoring by Aqua/MODIS is
examined on the large tropical oligo- to mesotrophic lagoon of New Caledonia (23,900 km2). The classical OC3
algorithm developed for MODIS can only be applied in deep waters. In shallow water, when the water is clear with a
weak attenuation, the bottom reflectance influences the surface reflectance and then induces an error in the chlorophyll
determination. Here, a new OC3-type polynom, relating satellite reflectance ratios and chlorophyll, was determined from
bio-optical data collected during a cruise (Valhybio) on the R/V Alis in the frame of the Programme National de
Télédétection Spatiale. From the 22th of March to the 9th of April, data were collected during two surveys of the same
network. A total of 170 in situ bio-optical measurements in the South Western and South lagoons of New Caledonia
were obtained, within a 2 weeks interval (70 non-cloudy match-ups). Four Modis images were acquired during this
cruise with moderate to good atmospheric conditions. The new polynom gives a RMS of 14.8% and a MNB of - 9% and
gives a better representation of the "true" water column chlorophyll concentration of the New Caledonia lagoon.
A workshop on fisheries was held in Noumea on November 21, 2008 to address remote-sensing applications to fisheries adapted to the particular needs and problems of Western and Central Pacific Island countries. During the workshop, presentations and discussions covered various topics related to remote sensing of coastal and open ocean waters and its applications to fisheries. Participants were introduced to remote sensing of ocean colour and its significance vis-à-vis the marine food web. Applications to fisheries included improvements of fisheries operations to increase efficiency of fishing effort, assessment of fish stocks health, growth and recruitment, and ecosystem dynamics. A project on the Societal Applications in Fisheries & Aquaculture using Remote Sensing Imagery (SAFARI) and a global Network for marine ecosystem management (ChloroGIN) were also presented. The particular issues arising in the use of remote sensing for fisheries in the tropical island regimes were reviewed and recommendations on the use of remote sensing in the context of fisheries were presented.
During the period 2000-2005, the atmospheric dynamic showed a significant influence on the dust inputs dynamic and, as a result, on the primary production of the northwest African Upwelling System since 2000 to 2005. In this period, the annual mean sea level pressure became higher, ranging from 1014 to 1015 mb. Mean annual zonal wind intensity became higher (from 1.1 to 1.8 m s-1), while the mean annual meridional wind reduced from 6.2 to 5.3 m s-1. Mean annual satellite-derived AVHRR/NOAA Sea Surface Temperature recorded in the northwest African Upwelling becomes warmer with 18.3°C to 18.8°C in Cape Ghir, and from 19.5°C to 20.3°C north Canary Islands waters. Chlorophyll data from SeaWiFS/OV-2 showed a different pattern trend. Mean annual CHL levels increased at eutrophic-like waters of Cape Ghir from 0.65 mg m-3 to 0.9 mg m-. However, data were significantly reduced from 0.59 mg m-3 to 0.31 mg m-3 in oligotrophic-like waters of the Canary Islands. Changes observed in the role of CHL during the last 6-years period could be associated to intensive dust deposition and the exceptional weather warming observed in this area since 2000. However, it is addressed to a single 7 years period and conclusions on possible links between dust deposition and marine biochemistry activity cannot be generalized.
For a large class of practical applications, based on second order nonlinear optical effects, one needs not only noncentrosymmetric molecules, like charge transfer molecules, but also their assemblage to macroscopically noncentrosymmetric materials.