Sampled SSH and error fields#
At each pass, for each cycle, an output netCDF file containing the SSH
interpolated from the model (if ssh_plugin
is
not set to None
), and the different errors. The naming and the file format are
compliant with SWOT’s PDD (Product Description Document), set
complete_product
key to True
to
store all the variables and False
to store only the one compute by the
simulator.
You can also select the output type
product_type
among basic
, expert
,
unsmoothed
, and wind_wave
. Default is expert
and details are in the
corresponding XML file.
The output directory is defined in
working_directory
key, default is the
user’s root. The output file names are stored in the output directory in
karin/<year>
directory for SWOT and nadir/<year>
directory for the
nadir. The naming follows the pattern :
SWOT_L2_LR_Expert_[cycle]_[pass]_[start_time]_[stop_time]_DG10_01.nc
for the Karin products andSWOT_GPR_2PTP[cycle]_[pass]_[start_time]_[stop_time].nc
for the nadir products.
The interpolation method is specified in your SSH plugin. pangeo-pyinterp module is used in the examples.
The nadir
and swath
parameters enable (parameter set to True
) or disable (parameter set to
False
) the generation of these products.
Computation of errors
are specified as a list:
noise = ['altimeter',
'baseline_dilation',
'karin',
'corrected_roll_phase',
'timing',
'wet_troposphere']
Note
corrected_roll_phase
error will generate already cross-calibrated
roll-phase error whereas roll_phase
will generate errors before
cross-calibration.
A repeat length
len_repeat = 2000
key
defines the wavelength in km to repeat the noise and is used for all noises. The
path to the file that contains instrumental errors is mentioned in
error_spectrum
key. It is possible to
specify the seed for Randomstate in nseed
. The
following parameters are specific to each noise component:
KaRIN: The file noise that contains the spectrum is available in
karin_noise
, a constantswh
can be setswh=2
or interpolated from a model SWH specified in the pluginswh_plugin
.Roll-phase: To use the already cross-calibrated roll phase, download the file from the FTP (https://ftp.odl.bzh/swot) and specify the path in the
corrected_roll_phase_dataset
key. So far, the following files are available:data_sim_slope_v0.nc
: One year of cross-calibrated roll-phasedata_sim_slope_2cycles_v0.nc
: Two cycles of cross-calibrated roll-phase
Wet troposphere: The number of beams used to correct the wet troposphere is set in
nbeam
variable. The beam position of each beam can be set as a list inbeam_position
, and the gaussian footprint can be changed usingsigma
variable.