xsar 2024.11.18

Python xarray library to use Level-1 GRD Synthetic Aperture Radar products

xsar

Synthetic Aperture Radar (SAR) Level-1 GRD python mapper for efficient xarray/dask based processing

This python library allow to apply different operation on SAR images such as:

• calibration
• de-noising
• re-sampling

The library is working regardless it is a Sentinel-1, a RadarSAT-2 or a RCM product.

The library is providing variables such as longitude , latitude, incidence_angle or sigma0 at native product resolution or coarser resolution.

The library perform resampling that are suitable for GRD (i.e. ground projected) SAR images. The same method is used for WV SLC, and one can consider the approximation still valid because the WV image is only 20 km X 20 km.

But for TOPS (IW or EW) SLC products we recommend to use xsarslc

Install

Conda

1. Install xsar (without the readers)

For a faster installation and less conflicts between packages, it is better to make the installation with micromamba

conda install -c conda-forge mamba

2. install xsar (without the readers)

micromamba install -c conda-forge xsar

3. Add optional dependencies

• Add use of Radarsat-2 :

micromamba install -c conda-forge xradarsat2

• Add use of RCM (RadarSat Constellation Mission)

pip install xarray-safe-rcm

• Add use of Sentinel-1

micromamba install -c conda-forge xarray-safe-s1

Pypi

1. install xsar (this will only allow to use Sentinel-1)

pip install xsar

2. install xsar with optional dependencies (to use Radarsat-2, RCM...)

• install xsar including Sentinel-1 :

pip install xsar[S1]

• install xsar including Radarsat-2 :

pip install xsar[RS2]

• install xsar including RCM :

pip install xsar[RCM]

• install xsar including multiple readers (here Radarsat-2 and RCM):

pip install xsar[RS2,RCM]

>>> import xsar
>>> import xarray
>>> xarray.open_dataset('S1A_IW_GRDH_1SDV_20170907T103020_20170907T103045_018268_01EB76_Z010.SAFE')

<xarray.Dataset>
Dimensions:               (atrack: 16778, pol: 2, xtrack: 25187)
Coordinates:
  * atrack                (atrack) int64 0 1 2 3 4 ... 16774 16775 16776 16777
  * pol                   (pol) object 'VV' 'VH'
  * xtrack                (xtrack) int64 0 1 2 3 4 ... 25183 25184 25185 25186
    spatial_ref           int64 ...
Data variables: (12/19)
    time                  (atrack) timedelta64[ns] ...
    digital_number        (pol, atrack, xtrack) uint16 ...
    land_mask             (atrack, xtrack) int8 ...
    ground_heading        (atrack, xtrack) float32 ...
    sigma0_raw            (pol, atrack, xtrack) float64 ...
    nesz                  (pol, atrack, xtrack) float64 ...
    ...                    ...
    longitude             (atrack, xtrack) float64 ...
    latitude              (atrack, xtrack) float64 ...
    velocity              (atrack) float64 ...
    range_ground_spacing  (xtrack) float64 ...
    sigma0                (pol, atrack, xtrack) float64 ...
    gamma0                (pol, atrack, xtrack) float64 ...
Attributes: (12/14)
    ipf:               2.84
    platform:          SENTINEL-1A
    swath:             IW
    product:           GRDH
    pols:              VV VH
    name:              SENTINEL1_DS:/home/oarcher/SAFE/S1A_IW_GRDH_1SDV_20170...
    ...                ...
    footprint:         POLYGON ((-67.84221143971432 20.72564283093837, -70.22...
    coverage:          170km * 251km (atrack * xtrack )
    pixel_atrack_m:    10.152619433217325
    pixel_xtrack_m:    9.986179379582332
    orbit_pass:        Descending
    platform_heading:  -167.7668824808032

More information

For more install options and to use xsar, see documentation