Visual/IR (InfraRed)/Other data
Apart from the small scale sea-surface roughness which is measured by SAR, there are other properties of the ocean which can be measured by satellite sensors. These include
- the colour of the surface layers of the ocean
- the temperature of the sea surface;
- the variation of height (i.e. slope) of the sea surface
- the salinity of the sea surface
- sea surface roughness
From these primary measurements which are communicated to the satellite sensors via signals in the electromagnetic spectrum many other ocean parameters can be recovered. It depends on the phenomena that one wishes to study with the help of satellite data which data type is suitable as, like SAR data, they all have their individual measuring characteristics. In the following, we have restricted our studies mainly to the use of optical and thermal data measuring the colour and the temperature of the ocean. The reasons for this are that
- these data types are relatively easily available,
- they measure quantities that most people are familiar with from standard oceanographic measurements,
- they do not require a large amount of expert knowledge for processing and some basic analyses if certain points about their limitations are kept in mind.
However, some basic information on the other data types which will not be used in MARSAIS but which are mentioned above will be provided on this web site, along with some references to other sites recommended for
Tables of data sources and available data products for the various ocean properties can be found under the following links:
- ocean colour
- sea surface temperature
- sea surface slope
- sea surface roughness (scatterometry)
Whilst these tables cannot cover all available data sources, they provide a starting point for finding suitable data from the appropriate sensors and give an overview of availability, software requirements, processing levels and costs of specific data types.