7

Sentinel-2 has 13 bands with 3 distinct resolutions.

  • Band 1 60m
  • Band 2 10m
  • Band 3 10m
  • Band 4 10m
  • Band 5 20m
  • Band 6 20m
  • Band 7 20m
  • Band 8 10m
  • Band 8A 20m
  • Band 9 60m
  • Band 10 60m
  • Band 11 20m
  • Band 12 20m

This page just gives how they separate the spectrum. But does not elaborate on how these bands have different resolution (the technology behind it).

I am curious about the advantage of this variation in spatial resolution (since Landsat 8 has only 30m)?

1
  • 4
    Landsat 8 has actually bands with 15, 30, and 100 m resolution landsat.gsfc.nasa.gov/landsat-8/landsat-8-bands. It would waste resources in data transfer and storage to use let's say 10 m pixel size with thermal band because due to the long wavelength the true resolution just can't be that good.
    – user30184
    Mar 4 '17 at 12:09
9

I can provide three elements of the design of Sentinel-2 spectral band resolutions :

  • there is a data volume/ Data transmission rate issue : the data volume gathered by the Sentinel-2 is huge : 1 TB per day for each Sentinel-2. I guess the mission designers decided to provide the most frequently used bands at 10m, and the other bands at larger resolution. For instance, 3 bands are only needed for atmospheric correction, which can be processed at a lower resolution.

  • technology issues : Short Wave Infra Red detectors (SWIR, above 1 µm) can't be as small as the Visible and Near Infra-red detectors (VNIR, <1µm). Elementary detector size is 7µm for VNIR and 13 µm for SWIR. IN fact, the ratio (detector size/wavelength) stays roughly constant.

  • Signal to noise ratio issues. The 10 m bands are broad bands, with a lot of light coming in. So they can provide a good signal to noise ratio, even at 10m resolution. But bands 5,6,7,8A are here to catch thinner spectral features, related to the vegetation "red edge". Their bandwidths are much thinner than the 10m bands, so detectors are receiving less light, which is compensated by adding the measurements of 2*2 elementary detectors.

1
  • point 1 is clear. Will have to open my signal processing books for point 2 and 3. Could you perhaps point me in the direction of an elaborate explanation? Mar 10 '17 at 6:37
2

Each wavelength has a different reflection/radiation strength. Maybe this article about radiometry helps you or the book 'Remote Sensing and Image Interpretation' from Lillesand, Kiefer, Chipman link to amazon.com

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.