ISSN:0143-1161    

DOI:10.1080/01431169108929683

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Systems developed for tracking marine animals including fish, reptiles, mammals and birds using the.ARGOS system are described. Platform Terminal Transmitters (PTTs) attachable to animals now weigh less than 150 g and can be used on larger species of birds. Simultaneous remote sensing and location of animals using the NOAA satellites is described. Marine animals can only be tracked if they surface during a satellite overpass. New developments which permit animal location using fewer messages greatly increase the probability of successful tracking. Only satellite tracking can provide long-term ocean-wide coverage necessary for management and conservation of many important species.

ISSN:0143-1161    

DOI:10.1080/01431169108929684

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An objective analysis scheme has been modified and used for AVHRR imagery. The computing time involved in the sorting process applied to each interpolation point, has been significantly reduced exploiting the fact that satellite-derived data are regularly sampled and that the covariance function behaviour (monotonically decreasing) is known. Spatial gaps in the sea surface temperature (SST) maps resulting from cloud coverage, atmospheric phenomena and missing data were optimally interpolated using neighbouring, future and past pixels. The interpolated SST fields reproduce the relevant oceanographic features (and their evolution) but filter out the noise introduced by the split window atmospheric correction. Space and time correlation scales of 40km and 10days respectively were empirically determined as best choice for the correlation function parameters in the Ligurian Sea. These values are in agreement with previousin situobservations of meander wavelength and phase speed for the same area. Moreover, a comparison of objective analysis (OA) and compositing techniques results has shown that while the latter does not retain the rapidly varing features moving along the northern edge of the Ligurian gyre the former reproduces them accurately.

ISSN:0143-1161    

DOI:10.1080/01431169108929685

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Diurnal warming of the sea surface temperature (SST) is often observed in the spring and summer Advanced Very High Resolution Radiometer (AVHRR) imagery of the Mediterranean Sea. It masks SST features of oceano-graphic interest. Diurnally warmed regions, where low wind conditions prevail, exhibit smooth surface and thus are characterized by low reflected solar radiation except for specular reflection of the visible solar radiation. Utilization of this correlation through clustering of diurnally warmed areas in an infrared-visible histogram permits discrimination from areas where the SST is representative of the underlying bulk temperature.

ISSN:0143-1161    

DOI:10.1080/01431169108929686

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The water depth in coastal areas was assumed to be linear with the first principal component of the logarithms of the detected signals within the spectral bands of the satellite sensor. Hence, relative water depths (digital counts) were computed. Charts of absolute water depths were then derived by the application of several calibration points with known water depth. The charts produced in this way were compared with available sounding charts. Multi-temporal images were used to assess the quality of the method and to detect morphological changes.

ISSN:0143-1161    

DOI:10.1080/01431169108929687

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A brief balance of the attainments and limits in the modern halieutic (fishery biology and economy) field is stricken and shows off the gap between the present management structure and the present problems. The surface tuna fishery case is thoroughly studied, considering its specificity and its economical importance. From there, it appears that conclusive strides will be made by halieutic science through the knowledge of the relationship between tuna and its environment. Some tuna environment studies are presented through typical remote sensing examples and introduce the basis of a coherent theory of tuna behaviour which can be schematically summarized by this basic general hypothesis; namely, that if tuna are present in a zone they will be inclined to aggregate close to any anomalies (gradients) of parameters in their environmental sensing field. From there, several models are presented in order to assess or forecast surface tuna stocks. A second part analyses the potential and contribution of the aerospatial remote sensing in the halieutic field through several original examples which point out clearly that this technique is one of the only tools able to visualize some essential concepts in oceanography and halieutic science. Last, we propose a study in several countries within the framework of several activities to integrate remote sensing tools in the fishery management structure, and to establish the data acquisition system in remote sensing satellites. From this study, a true operational halieutic field can be created.

ISSN:0143-1161    

DOI:10.1080/01431169108929688

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Knowledge of the distribution of SPM is recognised to be of increasing importance in relation to the prediction of the fate of pollutants in the shelf seas. Persistent patterns in SPM and a marked annual cycle are observed in the shelf seas around the United Kingdom. Although concentrations of surface suspended particulate material can be related to the imagery, little insight into the processes causing the variations can be gained without knowledge of the depth variability. Assessment of the spatial variation was facilitated by regular conductivity, temperature, depth (CTD) and transmissometer surveys from March to October 1987, in an area of the Irish Sea where there were marked gradients in the sea surface reflectance. This showed that although surface concentrations showed similar trends to sea surface reflectance, vertical gradients in suspended particulate material were associated with the seasonal pycnocline. The time dependance of beam attenuation and its control by tidal currents were assessed by the analysis of a six month record of transmissometer and current meter data from a mixed-water site. Beam attenuation was found to be significantly related to the springs-neaps cycle, advective processes and to the time of year. The study shows that remotely-sensed sea surface reflectance data have a significant part to play in the measurement of suspended particulate material if they are coupled with a carefully planned survey ofin situoptical and oceanographic measurements.

ISSN:0143-1161    

DOI:10.1080/01431169108929689

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

MBB and subcontractors have conceived both of the main optical payload elements for the second-generation METEOSAT (i.e. the imaging radiometer and the infrared sounder) in studies performed under ESA/ESTEC contracts. The latter represents a new instrument type onboard METEOSAT and is dedicated to vertical temperature (CO2bands) and water vapour soundings. The optical, opto-mechanical and overall concepts for both instruments as defined by the MBB team are described here. Emphasis is placed on the outline of the new features of both instruments in terms of higher spatial and radiometric resolution, number of spectral channels and repetition rates, and their benefits for all users of METEOSAT. Also, the impact of these optical payload elements on the satellite and ground segment, in particular the user stations, is discussed.

ISSN:0143-1161    

DOI:10.1080/01431169108929690

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The reflective optics system imaging spectrometer (ROSIS) is an advanced sensor particularly tailored to measure ocean parameters, including chlorophyll fluorescence. Further applications are described. Emphasis is placed on the wide range of applications for both airborne and space-borne instruments, including water biomass detection and water quality measurements, atmospheric applications as well as those over ice and land surfaces. It provides ≤5 nm spectral resolution at 128 selectable spectral bands, dispersed by a grating onto a matrix detector array and 32° field of view, which may be more than doubled when matching more than one optical module, especially for space-borne missions where a high repetition rate is required. A ROSIS airborne prototype is currently under development in a joint project of DLR, GKSS and MBB. This instrument will become operational in mid-1991. The ROSIS concept and design is outlined, as well as the planning status for extensions.

ISSN:0143-1161    

DOI:10.1080/01431169108929691

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The Groupement pour le Développement de la Télédétection Aerospatiale, (GDTA), located in Toulouse, France, is a group of French organizations involved in remote sensing. A wide range of sensors is being used, operated or developed, especially in oceanography. The present paper describes the related activities of GDTA, from data acquisition to data management, data dissemination, training and technology transfer, showing various examples of cases studies in oceanography, using a wide range of sensors.

ISSN:0143-1161    

DOI:10.1080/01431169108929692

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor