python SAR processor for level-1 SLC product

`xsarslc` is a python package that allow to compute sar cross spectrum and advanced radar parameters from sentinel-1 slc products.it handles 3 modes of acquisitions iw , ew and wv.the source code is relying on `xarray` library.https://github.com/umr-lops/xsar_slcdocumentation is available here: https://cerweb.ifremer.fr/datarmor/sarwave/documentation/processor/sar/xsarslc/html/it contains an algorithm tehcnical baseline document (atbd) section, describing the equations of each processing steps and their rationales.

xsarslc 是一款 Python 软件包，允许从 Sentinel-1 SLC 产品中计算合成孔径雷达交叉谱和高级雷达参数。该软件包支持三种采集模式：IW、EW 和 WV。其源代码基于 `xarray` 库。详细文档可在此处查阅：https://cerweb.ifremer.fr/datarmor/sarwave/documentation/processor/sar/xsarslc/html。文档中包含了一个算法技术基线文档（ATBD）部分，其中描述了每个处理步骤的方程及其原理。