API reference¶

sigma0_detrend¶

xsarsea.sigma0_detrend(sigma0, inc_angle, wind_speed_gmf=10, wind_dir_gmf=45)¶

compute sigma0_detrend from sigma0 and inc_angle

Parameters

sigma0 (numpy-like) – linear sigma0
inc_angle (numpy-like) – incidence angle (deg). Must be same shape as sigma0
wind_speed_gmf (int, optional) – wind speed (m/s) used by gmf, by default 10
wind_dir_gmf (int, optional) – wind dir (deg relative to antenna) used by , by default 45

Returns

sigma0 detrend.

Return type

numpy-like

implemented from: ‘W. Koch, “Directional analysis of SAR images aiming at wind direction,” IEEE Trans. Geosci. Remote Sens., vol. 42, no. 4, pp. 702-710, 2004.’ https://ieeexplore.ieee.org/document/1288365 https://www.climate-service-center.de/imperia/md/content/gkss/institut_fuer_kuestenforschung/ksd/paper/kochw_ieee_2004.pdf

xsarsea.streaks.streaks_direction(sigma0)¶

Parameters: sigma0 (xarray.DataArray) – detrended sigma0, at 100m resolution (I1 in Koch(2004))
Returns: streaks direction, in range [-180,180], at 16km resolution. 0 deg is azimuth satelite track (not north)
Return type: xarray.DataArray

Notes

100m resolution sigma0_detrend is not checked. Koch(2004) say it should be 100m