AVNIR
=====
  see https://doi.org/10.1109/IGARSS.2007.4423393
  files
    AVNIR.csv

Landsat
=======
 see https://landsat.usgs.gov/spectral-characteristics-viewer
 files
   etmplus.csv
   landsat_8.csv

geoeye
======
  see https://apollomapping.com/blog/new-documents-atmospheric-correction-digitalglobe-satellites-2
  files
    geoeye1.csv

ikonos
======
  see https://web.archive.org/web/20150331094259/https://www.digitalglobe.com/sites/default/files/DigitalGlobe_Spectral_Response_1.pdf
  files
    ikonos.csv

pleiades
========
  see https://trac.osgeo.org/grass/ticket/3054
  files
    pleiades1a.csv
    pleiades1b.csv

PRISM
=====
  see ?
  files
    PRISM-B.csv
    PRISM-F.csv
    PRISM-N.csv

quickbird
=========
  see https://apollomapping.com/blog/new-documents-atmospheric-correction-digitalglobe-satellites-2
  files
    quickbird2.csv

rapideye
========
  see https://resa.planet.com/files/2014-06/Spectral_Response_Curves.pdf
  files
    rapideye.csv

sentinel
========
  see https://sentinels.copernicus.eu/documents/247904/685211/S2-SRF_COPE-GSEG-EOPG-TN-15-0007_3.0.xlsx
    updates on https://sentinels.copernicus.eu/web/sentinel/home
    go to Home › User Guides › Sentinel-2 MSI › S2-MSI Document Library
  files
    sentinel_2A_msi.csv

spot
====
  see https://trac.osgeo.org/grass/ticket/3054
  files
    spot6.csv
    spot7.csv
    VGT1_spot4.csv
    VGT2_spot5.csv

worldview2
==========
  see https://apollomapping.com/blog/new-documents-atmospheric-correction-digitalglobe-satellites-2
  files
    worldview2.csv

worldview3
==========
  see ?
  files
    worldview3.csv

worldview4
==========
  see https://www.digitalglobe.com/resources/technical-information -> https://dg-cms-uploads-production.s3.amazonaws.com/uploads/document/file/242/relative_spectral_response_WV4.pdf
  files
    worldview4.csv