Distributed data processing levels are the daily trajectory summary (l2p) and weekly/monthly gridded data (l3c). The content of products based on the near-real time and reprocessed input version are identical and marked by the timeliness tag in the filename and global attributes of the netCDF files.
L2P Trajectory
The Level-2 pre-processed (l2p) product contains daily information from CryoSat-2 at full resolution (see documentation).
Filenaming
The filename of l2p data indicated the timelines (nrt or ntc) and the date (e.g. 20181001) of the data file:
The global attributes of the netCDF file provide metadata such as citation, reference, time coverage and more. Use ncinfo filename.nc or tools like panoply to list the global attributes.
netCDF Variables
Parameter
Description
Unit
Comment
freeboard
freeboard of the sea ice layer
meter
freeboard_uncertainty
freeboard uncertainty
meter
latitude
latitude of satellite nadir measurement point
degrees north
longitude
longitude of satellite nadir measurement point
degrees east
radar_freeboard
elevation of retracked point above instantaneous sea surface height
meter
radar freeboard is defined as the elevation basedon the assumption of vacuum light speed without a snow propagation or range penetration correction
radar_freeboard_uncertainty
algorithm uncertainty (error propagation) of the radar freeeboard retrieval
meter
radar_mode
radar mode flag
None
flag meaning:
0: pulse limited (lrm) 1: sar 2: sar interferometric
region_code
Region code (adapted from NSIDC region mask with Baltic Sea added)
None
New in version 2.1
flag meaning:
0: Inland sea and lakes 1: Ice-free Oceans 2: Sea of Okhotsk 3: Bering 4: Hudson Bay 5: St John 6: Baffin Bay 7: East Greeland Sea 8 Barents Sea 9: Kara Sea 10: Laptev Sea 11: East Siberian Sea 12: Chukchi Sea 13: Beaufort Sea 14: Canadian Islands 15: Central Arctic 16: Baltic Sea 20: land 21: land outline