Time
The units used in the SRAL/MWR Level-2 products are SI units, except for angles which use degrees as opposed to radians.
Quantity | Unit | Symbol |
Length | metre | m |
Mass | kilogram | kg |
Time | second | s |
Angle | degree | ° |
Frequency | Hertz | Hz |
The SRAL/MWR Level-2 product variables may have an offset and/or a scale factor applied in the netCDF output files to maintain maximum precision using an integer data type variable. They shall be considered when reading the values of these variables. An example is shown below for the altitude variable at 1 Hz:
int alt(time);
alt:long_name = "1 Hz altitude of satellite";
alt:_FillValue = 2147483647;
alt:units = "m";
alt:add_offset = 1.30e+06;
alt:scale_factor = 1.00e-04;
alt:coordinates = "lon lat";
The data are stored in 32-bit integers (long). The value of the altitude expressed in metres (SI) of the satellite can be recovered using:
alt_si =(alt *scale_factor) + add_offset