Chemistry Reference
In-Depth Information
One of the major problems to overcome is the diversity of different sen-
sors, resulting in varying sampling rates, different sensor geometries,
swath widths and different data formats. The direct comparison of sensors
like IR/UV and laser fluorosensor for the evaluation of an oil spill or in the
case of larger quantities, IR/UV and microwave radiometer requires a good
understanding of the sensor characteristics, capabilities and restrictions.
Such an understanding may not be suitable for the routine operation by
none-scientifically trained personnel. Therefore, it is intended to evaluate
sensor data automatically and create results in such a way that an assess-
ment may be accomplished by operators that are not necessarily familiar
with all sensor characteristics and details. One step forward in such a con-
cept is the generation of a synthetic image from the various sensor images
which allows much faster interpretation of sensor data because there is
only one image visually describing the whole and often complex situation
over an oil spill. It is important to provide such investigative tools in real
time because it is obvious that evaluation and assessment of damages, re-
sulting in possible clean up operations, have to be made immediately.
5.1 Internal data processing
Next, the Oil Spill Scene Analysis System (OSSAS) is presented (Robbe
and Zielinski 2004, Robbe 2005). The task of OSSAS is the fully-auto-
mated generation of the requested high-level information onboard the sur-
veillance aircraft. This kind of data processing is hereby defined as
inter-
nal data processing
. In the case of the present application, the term 'end-
user' comprises the airborne sensor operator, the response crew at sea and
responsible authorities. Any further use of the internally derived high-level
information outside the surveillance aircraft is defined as
external informa-
tion processing
.
The overall functional diagram in Figure 6 illustrates the principal struc-
ture of OSSAS. According to the diagram, IR/UV-LS data are of central
importance for the function of the analysis system. This is true because the
IR/UV-LS is probably the most important near-range remote sensor for the
oil spill operator since it provides high-resolution imagery information on
relative oil thickness. While the thermal infrared (TIR) component of the
IR/UV-LS is used for visualizing thick oil, the corresponding NUV com-
ponent is used for mapping the total extent of the oil spill. IR/UV-LS data
are, therefore, considered as primary input for OSSAS. MWR and IALFS
data as well as external model input and data originating from other sen-
sors are considered as secondary input for the analysis system. The output
of OSSAS is shown in the bottom part of the overall functional diagram. It
includes the desired set of high-level information.
