Search found 135 matches

by OB WebDev - norman
Thu Apr 09, 2020 9:00 am America/New_York
Forum: All Questions/Comments
Question: Write L2_LAC_OC.nc data
Replies: 5

Write L2_LAC_OC.nc data

Hello,Our level-2 products are written in NetCDF4/HDF5 format.  Please see this page.        https://oceancolor.gsfc.nasa.gov/docs/format/l2nc/The SeaDAS software that we distribute can already read that format.If you are looking for a more detailed description of the format...
by OB WebDev - norman
Wed Apr 08, 2020 11:24 am America/New_York
Forum: All Questions/Comments
Question: browse.pl
Replies: 4

browse.pl

Hi Bruce,There have been many changes (added missions, file-name-convention changes, etc.)since this forum thread that have caused the suggested wget calls to no longer work.My old browse code (never intended for such uses) is still limping along while otherswork out a design for a new browser that ...
by OB WebDev - norman
Mon Apr 06, 2020 10:01 am America/New_York
Forum: All Questions/Comments
Question: Featured images
Replies: 10

Featured images

Hi Fabrizio,Those images look much better now.Indeed you can perform most of the same operations using ImageMagick as you can ingimp.  See, for instance, the "-compose" option to the convert command.https://imagemagick.org/Usage/compose/#mathNote, however, that sometimes blending mode...
by OB WebDev - norman
Thu Apr 02, 2020 2:02 pm America/New_York
Forum: All Questions/Comments
Question: Featured images
Replies: 10

Featured images

Oh, with regards to your comment about applying a palette under gimp: I do notuse the chlorophyll images in that way i.e. as indexed color look-up tables.  I blendthe gray-scale chlorophyll images with the other layers using blending modes suchas "soft light".  That particular bl...
by OB WebDev - norman
Thu Apr 02, 2020 1:55 pm America/New_York
Forum: All Questions/Comments
Question: Featured images
Replies: 10

Featured images

Hi Fabrizio,We have the same issues accessing our work place at Goddard Space Flight Center inMaryland.  Yes, these are challenging times.There is still something wrong with the files you are generating.  They should nothave those holes in the grid.  I notice that you have many key li...
by OB WebDev - norman
Thu Apr 02, 2020 11:25 am America/New_York
Forum: All Questions/Comments
Question: Surface and subsurface blooms in MODIS data
Replies: 2

Surface and subsurface blooms in MODIS data

Perhaps in the future we may be able to vertically resolve phytoplankton using
LIDAR from space.

See advance number 1 under the Satellite section of this paper.
https://doi.org/10.3389/fmars.2019.00251

Norman
by OB WebDev - norman
Tue Mar 31, 2020 10:11 am America/New_York
Forum: All Questions/Comments
Question: Featured images
Replies: 10

Featured images

Hi Fabrizio,I looked at a couple of your images, and the moiré patterns indicate that thechosen search radius passed to nearneighbor is too small for the spacing ofthe projected input data.  A couple of possibilities spring to mind.(a) I am not familiar with R.  Are you sure that your Rscr...
by OB WebDev - norman
Mon Mar 30, 2020 10:03 am America/New_York
Forum: All Questions/Comments
Question: Geolocation issue with l2gen
Replies: 4

Geolocation issue with l2gen

Hi Armin,

I have generally found the geolocation provided by the orthorectified
Landsat 8 data from USGS to be pretty good.  I would suspect the
land mask you are using is the problem.  The l2gen software does not
change the original projection supplied by USGS.

Norman
by OB WebDev - norman
Fri Mar 27, 2020 12:49 pm America/New_York
Forum: All Questions/Comments
Question: Geolocation issue with l2gen
Replies: 4

Geolocation issue with l2gen

Hi Armin,For Landsat, I would suggest that you not use the land-mask that comes along withl2gen; it is just not of high enough resolution or accuracy.  When I need to discriminatebetween land and water in Landsat 8 data, I like to compute rhos_865 from Band 5and choose a threshold reflectance t...
by OB WebDev - norman
Tue Mar 24, 2020 1:45 pm America/New_York
Forum: All Questions/Comments
Question: Size of 1 day level 2 data on global scale
Replies: 3

Size of 1 day level 2 data on global scale

Hi Eligio,Compression ratio will vary depending on the contents of the scene.L2 scenes that have large areas masked out (e.g. for land) willcompress much smaller than those with a more complete andvarying feature set.If I were you, I would set up a processing flow that downloadsscenes serially and d...