diff --git a/docs/examples/streaks.ipynb b/docs/examples/streaks.ipynb
index 41e118f..62cdd0b 100644
--- a/docs/examples/streaks.ipynb
+++ b/docs/examples/streaks.ipynb
@@ -55,6 +55,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "xsarsea.windspeed.gmfs.GmfModel.activate_gmfs_impl()\n",
     "xsarsea.windspeed.available_models()"
    ]
   },
@@ -138,7 +139,7 @@
     "streaks_geo['weight'] = streaks['weight']\n",
     "\n",
     "# convert directions from image convention to geographic convention\n",
-    "streaks_geo['streaks_dir'] =  xsarsea.dir_sample_to_geo(np.rad2deg(streaks['angle']), streaks_geo['ground_heading']) \n",
+    "streaks_geo['streaks_dir'] =  xsarsea.dir_sample_to_meteo(np.rad2deg(streaks['angle']), streaks_geo['ground_heading']) \n",
     "\n",
     "streaks_geo = streaks_geo.compute()\n",
     "\n",
@@ -228,7 +229,7 @@
    "source": [
     "#### Convertion between image convention and geographic convention\n",
     "\n",
-    "see [xsarsea.dir_geo_to_sample](../basic_api.rst#xsarsea.dir_geo_to_sample) and [xsarsea.dir_sample_to_geo](../basic_api.rst#xsarsea.dir_sample_to_geo)\n",
+    "see [xsarsea.dir_meteo_to_sample](../basic_api.rst#xsarsea.dir_meteo_to_sample) and [xsarsea.dir_sample_to_meteo](../basic_api.rst#xsarsea.dir_sample_to_meteo)\n",
     "\n"
    ]
   },
diff --git a/docs/examples/windspeed_inversion.ipynb b/docs/examples/windspeed_inversion.ipynb
index 683b830..f3c63b6 100644
--- a/docs/examples/windspeed_inversion.ipynb
+++ b/docs/examples/windspeed_inversion.ipynb
@@ -18,7 +18,7 @@
     "> .. warning::\n",
     "   **Use of ancillary wind**\n",
     "\n",
-    "> We suggest to go from `ancillary_wind = -np.conj(sarwing_ds.owi_ancillary_wind)` to `sarwing_ds.owi_ancillary_wind`` ; then it won't match sarwing results anymore\n",
+    "> We suggest to go from `ancillary_wind = -np.conj(sarwing_ds.owi_ancillary_wind)` to `ancillary_wind = sarwing_ds.owi_ancillary_wind` ; then it won't match sarwing results anymore\n",
     "\n"
    ]
   },
@@ -82,7 +82,7 @@
     "\n",
     "Ecmwf wind is stored in owi file in *geographical* (deg N/S) convention. `xsarsea.windspeed` need it relative to *sample* (ie antenna), as a complex number.\n",
     "\n",
-    "We use [xsarsea.dir_geo_to_sample](../basic_api.rst#xsarsea.dir_geo_to_sample) to convert `sarwing_ds.owiEcmwfWindDirection` (deg) to radians, relative to sample, using `sarwing_ds.owiHeading`\n"
+    "We use [xsarsea.dir_meteo_to_sample](../basic_api.rst#xsarsea.dir_meteo_to_sample) to convert `sarwing_ds.owiEcmwfWindDirection` (deg) to radians, relative to sample, using `sarwing_ds.owiHeading`\n"
    ]
   },
   {
@@ -92,7 +92,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "owi_ecmwf_wind = sarwing_ds.owiEcmwfWindSpeed * np.exp(1j* xsarsea.dir_geo_to_sample(sarwing_ds.owiEcmwfWindDirection, sarwing_ds.owiHeading))\n",
+    "owi_ecmwf_wind = sarwing_ds.owiEcmwfWindSpeed * np.exp(1j* xsarsea.dir_meteo_to_sample(sarwing_ds.owiEcmwfWindDirection, sarwing_ds.owiHeading))\n",
     "sarwing_ds = xr.merge([\n",
     "    sarwing_ds,\n",
     "    owi_ecmwf_wind.to_dataset(name='owi_ancillary_wind'),\n",
@@ -127,7 +127,7 @@
     "vectorfield = hv.VectorField(\n",
     "    (\n",
     "        sub_sarwing_ds.sample, sub_sarwing_ds.line,\n",
-    "        xsarsea.dir_geo_to_sample(sub_sarwing_ds.owiEcmwfWindDirection, sub_sarwing_ds.owiHeading),\n",
+    "        xsarsea.dir_meteo_to_sample(sub_sarwing_ds.owiEcmwfWindDirection, sub_sarwing_ds.owiHeading),\n",
     "        sub_sarwing_ds.owiEcmwfWindSpeed\n",
     "    )\n",
     ")\n",
@@ -478,7 +478,7 @@
     "vectorfield = hv.VectorField(\n",
     "    (\n",
     "        sub_sarwing_ds.sample, sub_sarwing_ds.line,\n",
-    "        xsarsea.dir_geo_to_sample(sarwing_ds[\"winddir_dual\"] ,sub_sarwing_ds.owiHeading),\n",
+    "        xsarsea.dir_meteo_to_sample(sarwing_ds[\"winddir_dual\"] ,sub_sarwing_ds.owiHeading),\n",
     "        np.abs(wind_dual).isel(line=slice(None, None, 10), sample=slice(None, None, 10))\n",
     "    )\n",
     ")\n",
@@ -506,7 +506,7 @@
     "vectorfield = hv.VectorField(\n",
     "    (\n",
     "        sub_sarwing_ds.sample, sub_sarwing_ds.line,\n",
-    "        xsarsea.dir_geo_to_sample(sub_sarwing_ds.owiWindDirection ,sub_sarwing_ds.owiHeading),\n",
+    "        xsarsea.dir_meteo_to_sample(sub_sarwing_ds.owiWindDirection ,sub_sarwing_ds.owiHeading),\n",
     "        sub_sarwing_ds.owiWindSpeed\n",
     "    )\n",
     ")\n",
diff --git a/docs/examples/windspeed_retrieval_L1.ipynb b/docs/examples/windspeed_retrieval_L1.ipynb
index 18b4ad2..2a514b6 100644
--- a/docs/examples/windspeed_retrieval_L1.ipynb
+++ b/docs/examples/windspeed_retrieval_L1.ipynb
@@ -249,7 +249,7 @@
     "dataset['sigma0_ocean'] = xr.where(dataset['sigma0'] <= 0, 1e-15, xsar_obj.dataset['sigma0'])\n",
     "dataset['ancillary_wind_direction'] = (90. - np.rad2deg(np.arctan2(dataset.model_V10, dataset.model_U10)) + 180) % 360\n",
     "dataset['ancillary_wind_speed'] = np.sqrt(dataset['model_U10']**2+dataset['model_V10']**2)\n",
-    "dataset['ancillary_wind'] = dataset.ancillary_wind_speed * np.exp(1j * xsarsea.dir_geo_to_sample(dataset.ancillary_wind_direction, dataset.ground_heading)) # ref antenna"
+    "dataset['ancillary_wind'] = dataset.ancillary_wind_speed * np.exp(1j * xsarsea.dir_meteo_to_sample(dataset.ancillary_wind_direction, dataset.ground_heading)) # ref antenna"
    ]
   },
   {
@@ -471,7 +471,7 @@
     "vectorfield = hv.VectorField(\n",
     "    (\n",
     "        sub_ds.sample, sub_ds.line,\n",
-    "        xsarsea.dir_geo_to_sample(sub_ds.winddir_dual,sub_ds.ground_heading),\n",
+    "        xsarsea.dir_meteo_to_sample(sub_ds.winddir_dual,sub_ds.ground_heading),\n",
     "        sub_ds.windspeed_dual\n",
     "    )\n",
     ")\n",
@@ -491,7 +491,7 @@
     "vectorfield = hv.VectorField(\n",
     "    (\n",
     "        sub_ds.sample, sub_ds.line,\n",
-    "        xsarsea.dir_geo_to_sample(sub_ds.ancillary_wind_direction,sub_ds.ground_heading),\n",
+    "        xsarsea.dir_meteo_to_sample(sub_ds.ancillary_wind_direction,sub_ds.ground_heading),\n",
     "        sub_ds.ancillary_wind_speed\n",
     "    )\n",
     ")\n",
diff --git a/src/xsarsea/__init__.py b/src/xsarsea/__init__.py
index b8e73dc..a78a1b0 100644
--- a/src/xsarsea/__init__.py
+++ b/src/xsarsea/__init__.py
@@ -1,10 +1,10 @@
-__all__ = ['sigma0_detrend', 'dir_geo_to_sample', 'dir_sample_to_geo', 'get_test_file']
+__all__ = ['sigma0_detrend', 'dir_meteo_to_sample',
+           'dir_sample_to_meteo', 'dir_meteo_to_oceano', 'dir_oceano_to_meteo', 'dir_to_180', 'dir_to_360', 'get_test_file']
 
 from .utils import get_test_file
-from .xsarsea import dir_geo_to_sample, dir_sample_to_geo, sigma0_detrend, read_sarwing_owi
+from .xsarsea import dir_meteo_to_sample, dir_sample_to_meteo, sigma0_detrend, dir_meteo_to_oceano, dir_oceano_to_meteo, dir_to_180, dir_to_360,  read_sarwing_owi
 try:
     from importlib import metadata
 except ImportError:  # for Python<3.8
     import importlib_metadata as metadata
 __version__ = metadata.version('xsarsea')
-
diff --git a/src/xsarsea/gradients.py b/src/xsarsea/gradients.py
index 34bce4a..0db0fc4 100644
--- a/src/xsarsea/gradients.py
+++ b/src/xsarsea/gradients.py
@@ -12,7 +12,11 @@
 __all__ = ['Gradients', 'Gradients2D',
            'circ_smooth', 'PlotGradients', 'circ_hist']
 
-import cv2
+try:
+    import cv2
+except:
+    import cv2
+
 import numpy as np
 from scipy import signal, ndimage
 import xarray as xr
diff --git a/src/xsarsea/windspeed/__init__.py b/src/xsarsea/windspeed/__init__.py
index 5754e66..98f808d 100644
--- a/src/xsarsea/windspeed/__init__.py
+++ b/src/xsarsea/windspeed/__init__.py
@@ -2,9 +2,9 @@
 windspeed module, for retrieving wind speed from sigma0 and models.
 """
 __all__ = ['invert_from_model', 'available_models', 'get_model', 'register_cmod7',
-           'register_sarwing_luts', 'register_nc_luts', 'nesz_flattening', 'GmfModel']
+           'register_sarwing_luts', 'register_nc_luts', 'register_luts', 'nesz_flattening', 'GmfModel']
 from .windspeed import invert_from_model
-from .models import available_models, get_model, register_nc_luts
+from .models import available_models, get_model, register_nc_luts, register_luts
 from .sarwing_luts import register_sarwing_luts
 from .cmod7 import register_cmod7
 from .utils import nesz_flattening, get_dsig
diff --git a/src/xsarsea/windspeed/models.py b/src/xsarsea/windspeed/models.py
index 20dab2d..be41ea5 100644
--- a/src/xsarsea/windspeed/models.py
+++ b/src/xsarsea/windspeed/models.py
@@ -273,7 +273,7 @@ def __call__(self, inc, wspd, phi=None, broadcast=False):
         wspd: array-like
             windspeed
         phi: array-like or None
-            wind direction, in **gmf convention**
+            wind direction relative to antenna
         broadcast: bool
             | If True, input arrays will be broadcasted to the same dimensions, and output will have the same dimension.
             | This option is only available for :func:`~xsarsea.windspeed.gmfs.GmfModel`
@@ -397,7 +397,7 @@ def _raw_lut(self, **kwargs):
         return lut
 
 
-def register_nc_luts(topdir, gmf_names=None, **kwargs):
+def register_nc_luts(topdir, gmf_names=None):
     """
     Register all netcdf luts found under `topdir`.
 
@@ -518,3 +518,32 @@ def get_model(name):
             raise KeyError('model %s not found' % name)
 
     return model
+
+
+def register_luts(topdir=None, topdir_cmod7=None):
+    """
+    Register gmfModel luts and ncLutModel luts
+
+    Parameters
+    ----------
+    topdir: str
+        top dir path to nc luts.
+    
+    topdir_cmod7: str
+        top dir path to cmod7 luts.
+
+    kwargs: dict
+        kwargs to pass to register_nc_luts
+    """
+    
+    # register gmf luts
+    import xsarsea.windspeed as windspeed
+    windspeed.GmfModel.activate_gmfs_impl()
+
+    # register nc luts
+    if topdir != None:
+        register_nc_luts(topdir)
+
+    # register cmod7
+    if topdir_cmod7 != None:
+        windspeed.register_cmod7(topdir_cmod7)
diff --git a/src/xsarsea/windspeed/windspeed.py b/src/xsarsea/windspeed/windspeed.py
index b5d69b9..32de90b 100644
--- a/src/xsarsea/windspeed/windspeed.py
+++ b/src/xsarsea/windspeed/windspeed.py
@@ -23,8 +23,7 @@ def invert_from_model(inc, sigma0, sigma0_dual=None, /, ancillary_wind=None, dsi
         sigma0 in cross pol for dualpol invertion
     ancillary_wind=: xarray.DataArray (numpy.complex28)
         ancillary wind
-
-            | (for example ecmwf winds), in **model convention**
+            | (for example ecmwf winds), in **antenna convention**
     model=: str or tuple
         model to use.
 
@@ -46,8 +45,7 @@ def invert_from_model(inc, sigma0, sigma0_dual=None, /, ancillary_wind=None, dsi
     -------
     xarray.DataArray or tuple
         If available (copol or dualpol), the returned array is `np.complex64`, with the angle of the returned array is
-        inverted direction in **gmf convention** (use `-np.conj(result))` to get it in standard convention)
-
+        inverted direction in **antenna convention**
     See Also
     --------
     xsarsea.windspeed.available_models
@@ -170,12 +168,6 @@ def __invert_from_model_1d(inc_1d, sigma0_co_db_1d, sigma0_cr_db_1d, dsig_cr_1d,
             # this function will be vectorized with 'numba.guvectorize' or 'numpy.frompyfunc'
             # set debug=True below to force 'numpy.frompyfunc', so you can debug this code
 
-            # gmf and lut doesn't have the same direction convention than xsarsea in the sample direction
-            # for xsarsea, positive sample means in the sample increasing direction
-            # for gmf and lut, positive means in the sample decreasing direction
-            # we switch ancillary wind to the gmf convention
-            # ancillary_wind_1d = -np.conj(ancillary_wind_1d)
-
             for i in range(len(inc_1d)):
                 one_inc = inc_1d[i]
                 one_sigma0_co_db = sigma0_co_db_1d[i]
diff --git a/src/xsarsea/xsarsea.py b/src/xsarsea/xsarsea.py
index f94e401..705cd65 100644
--- a/src/xsarsea/xsarsea.py
+++ b/src/xsarsea/xsarsea.py
@@ -89,13 +89,13 @@ def read_sarwing_owi(owi_file):
     return sarwing_ds
 
 
-def dir_geo_to_sample(geo_dir, ground_heading):
+def dir_meteo_to_sample(meteo_dir, ground_heading):
     """
-    Convert geographical N/S direction to image convention
+    Convert meteorological N/S direction to image convention
 
     Parameters
     ----------
-    geo_dir: geographical direction in degrees north
+    meteo_dir: meteorological direction in degrees north
     ground_heading: azimuth at position, in degrees north
 
     Returns
@@ -104,22 +104,94 @@ def dir_geo_to_sample(geo_dir, ground_heading):
         same shape as input. angle in radian, relative to sample, anticlockwise
     """
 
-    return np.pi / 2 - np.deg2rad(geo_dir - ground_heading)
+    return np.pi / 2 - np.deg2rad(meteo_dir - ground_heading)
 
 
-def dir_sample_to_geo(sample_dir, ground_heading):
+def dir_sample_to_meteo(sample_dir, ground_heading):
     """
-    Convert image direction relative to antenna to geographical direction
+    Convert image direction relative to antenna to meteorological direction
 
     Parameters
     ----------
-    sample_dir: geographical direction in degrees north
+    sample_dir: angle in degrees, relative to sample, anticlockwise
     ground_heading: azimuth at position, in degrees north
 
     Returns
     -------
     np.float64
-        same shape as input. angle in degrees, relative to sample, anticlockwise
+        same shape as input. meteorological direction in degrees north
     """
 
     return 90 - sample_dir + ground_heading
+
+
+def dir_meteo_to_oceano(meteo_dir):
+    """
+    Convert meteorological direction to oceanographic direction
+
+    Parameters
+    ----------
+    meteo_dir: float
+        Wind direction in meteorological convention (clockwise, from), ex: 0°=from north, 90°=from east
+
+    Returns
+    -------
+    float
+        Wind direction in oceanographic convention (clockwise, to), ex: 0°=to north, 90°=to east
+    """
+    oceano_dir = (meteo_dir + 180) % 360
+    return oceano_dir
+
+
+def dir_oceano_to_meteo(oceano_dir):
+    """
+    Convert oceanographic direction to meteorological direction
+
+    Parameters
+    ----------
+    oceano_dir: float
+        Wind direction in oceanographic convention (clockwise, to), ex: 0°=to north, 90°=to east
+
+    Returns
+    -------
+    float
+        Wind direction in meteorological convention (clockwise, from), ex: 0°=from north, 90°=from east
+    """
+    meteo_dir = (oceano_dir - 180) % 360
+    return meteo_dir
+
+
+def dir_to_180(angle):
+    """
+    Convert angle to [-180;180]
+
+    Parameters
+    ----------
+    angle: float
+        angle in degrees
+
+    Returns
+    -------
+    float
+        angle in degrees
+    """
+    angle_180 = (angle + 180) % 360 - 180
+    return angle_180
+
+
+def dir_to_360(angle):
+    """
+    Convert angle to [0;360]
+
+    Parameters
+    ----------
+    angle: float
+        angle in degrees
+
+    Returns
+    -------
+    float
+        angle in degrees
+    """
+    angle_360 = (angle + 360) % 360
+    return angle_360
diff --git a/test/test_xsarsea.py b/test/test_xsarsea.py
index 6057e9c..dca1f30 100644
--- a/test/test_xsarsea.py
+++ b/test/test_xsarsea.py
@@ -84,7 +84,7 @@ def test_inversion():
         line=slice(0, 50), sample=slice(0, 60))
 
     owi_ecmwf_wind = sarwing_ds.owiEcmwfWindSpeed * np.exp(
-        1j * xsarsea.dir_geo_to_sample(sarwing_ds.owiEcmwfWindDirection, sarwing_ds.owiHeading))
+        1j * xsarsea.dir_meteo_to_sample(sarwing_ds.owiEcmwfWindDirection, sarwing_ds.owiHeading))
     sarwing_ds = xr.merge([
         sarwing_ds,
         owi_ecmwf_wind.to_dataset(name='owi_ancillary_wind'),