One of the first steps that was required in the SFI bathymetry project that I posted about recently was to find free data. We had agreed at the kick-off meeting that three parameters were essential, primarily due to findings from the pilot Dublin bay study. These were:
1) The imagery had to coincide with the LiDAR calibration datasets
2) The imagery had to have a blue band
3) The imagery had to be of higher resolution than 30m.
Of particular relevance to my previous post was point 2, where scientists used a coastal blue band to look for submerged whales.
Satellites that have a 'coastal blue' band like Worldview 2 or Landsat 8 can penetrate water to greater depths than those that are restricted to the traditional blue portion of the spectrum.
Anyway - these 3 requirements were quite restrictive when matching the datasets with imagery and most of the free datasets had to be eliminated. The industry partner, TWM suggested I contact the European Space Agency (ESA) representative, who is an employee of Enterprise Ireland and see could we get some free ESA data for the project.
This was an excellent idea so I completed and submitted a, 'Third Party Mission' application and after some toing and froing we were granted access to, and a quota for, imagery from two commercial satellites - RapidEye and SPOT. Although SPOT doesn't have a blue band - it will allow us to to test the importance of the blue band for turbid waters - the findings of in the literature seem to imply that the green band is rpeferable for turbid waters and Irish waters are certainly that. plus it's always useful to have an extra dataset. So now we have some Landsat 5 imagery, RapidEye and SPOT.
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