nd 0.0.0

A Python library for n-dimensional Earth observation data processing

nd

This package contains a selection of tools to handle and analyze satellite data.

nd is making heavy use of the xarray library. dask is used for parallelization.

The GDAL library is only used as a compatibility layer in nd.io to enable reading supported file formats. Internally, all data is passed around as xarray Datasets and all provided functions expect this format as inputs. nd.io.from_gdal_dataset may be used to convert any gdal.Dataset object or GDAL-readable file into an xarray Dataset.

---

Submodules

nd.io

Several functions to read and write satellite data.

• to/from NetCDF
• read data from open GDAL datasets and any GDAL-readable file
• deal with complex-valued data (not supported by NetCDF) by disassembling into two reals when writing to NetCDF, and vice versa when reading.

nd.change

A module implementing change detection algorithms.

• convert dual polarization data into the complex covariance matrix representation
• OmnibusTest (change detection algorithm by Conradsen et al. (2015))

nd.classify

A collection of classification and clustering methods.

... work in progress ...

nd.filter

Implements several filters, currently:

• kernel convolutions
• non-local means

nd.utils

Several utility functions.

• split/merge numpy arrays, xarray datasets, ...
• parallelize operations acting on xarray datasets

nd.warp

Given a dataset with Ground Control Points (GCPs), usually in the form of a tie point grid, warp the dataset onto an equirectangular projection (WGS84), such that lat/lon directly correspond to the y and x coordinates, respectively.

This makes concatenating datasets easier and reduces storage size, because lat/lon coordinates do not need to be stored for each pixel.

nd.visualize

Several functions to quickly visualize data.

• create RGB images from data
• create video from a spatiotemporal dataset

nd.tiling

• Split a dataset into tiles.
• Read a tiled dataset.
• Map a function across a tiled dataset.
• Create and merge tiles with buffer to avoid edge affects.