Naiad search in details

Naiad is mainly about spatio-temporal search, but finer search on some specific properties registered with the granule footprint and time coverage can also be performed.

This section details how to search granules both with the command line tool and the python API. It explores in more details the available options.

naiad-search command-line tool

So let’s search for some granules intersecting an area and period of interest. This is done with naiad-search command.

All you need to know first is the name of the index you want to search your product granules from. Here we use an index called test_pdgs_sl_2_wct____nr in which we registered SLSTR L1 granules from sentinel-3.

Get all options with:

naiad-search --help

Selection options

Get everything! (be careful!):

naiad-search test_pdgs_sl_2_wct____nr

Add a time frame restriction:

naiad-search test_pdgs_sl_2_wct____nr --start 2016-11-09 --end 2016-11-10

And now some area, defined as lonmin, latmin, lonmax, latmax:

naiad-search test_pdgs_sl_2_wct____nr --start 2016-11-09 --end 2016-11-10 --area='-20,-20,20,20'

You can request several products at the same time using a coma-separated list:

naiad-search test_pdgs_sl_2_wct____nr,test_pdgs_sl_2_wst____nr  --start 2016-11-19 --end 2016-11-20 --area='-20,-20,20,20'

You can specify some constraints on the granule properties, if they have been registered in the product index.

For instance, get all granules with a cloud coverage (slstr_class_summary_1km_cloudy_region_pix property) lower than 10%:

naiad-search test_pdgs_sl_2_wct____nr --granule_constraints='slstr_class_summary_1km_cloudy_region_pix le 10' --start 2016-11-09 --end 2016-11-10

Multiple constraints can be combined, separating the different constraints by a ;, here for instance testing both cloud and land coverage:

naiad-search test_pdgs_sl_2_wct____nr --granule_constraints='slstr_class_summary_1km_cloudy_region_pix le 10;slstr_class_summary_1km_land_pix le 50' --start 2016-11-09 --end 2016-11-10

Format options

If Naiad has been properly configured, you can get the full path to the selected granules with --full-path option:

naiad-search test_pdgs_sl_2_wct____nr --granule_constraints='slstr_class_summary_1km_cloudy_region_pix le 10;slstr_class_summary_1km_land_pix le 50' --start 2016-11-09 --end 2016-11-10 --full-path

--show option allows you to check the location of each selected granules on a map:

naiad-search test_pdgs_sl_2_wct____nr --granule_constraints='slstr_class_summary_1km_cloudy_region_pix le 10;slstr_class_summary_1km_land_pix le 50' --start 2016-11-09 --end 2016-11-10 --show

--output-format json will return the selected granules as a json list:

naiad-search test_pdgs_sl_2_wct____nr --granule_constraints='slstr_class_summary_1km_cloudy_region_pix le 10;slstr_class_summary_1km_land_pix le 50' --start 2016-11-09 --end 2016-11-10 --output-format json