Terminology

Acquisition

The date of SAR acquisition or image, expressed as a datetime.datetime object.

Pair

A pair is a combination of two SAR acquisitions in acquisition order.

Warning

In FanInSAR, a Pair must be in acquisition order, which means that the first acquisition should be earlier than the second acquisition. For example, a pair of (2018-01-01, 2018-02-01) is valid, but a pair of (2018-02-01, 2018-01-01) is invalid. If an invalid pair is provided, FanInSAR may yield unexpected results.

Pairs

A collection of pairs.

Loop

A loop contains a list of edge pairs and one diagonal pair. See paper [1] for more details.

Loops

A collection of loops.

TripletLoop

triplet loop is a special loop that contains three pairs. See paper [1] for more details.

TripletLoops

A collection of triplet loops.

SBASNetwork

A collection of loops and pairs.

CRS

A coordinate reference system (CRS) is a coordinate-based local, regional, or global system used to locate geographical entities. In FanInSAR, the CRS is handled by the rasterio and pyproj packages. A valid CRS input for FanInSAR can be any type supported by the pyproj.crs.CRS.from_user_input() method.

[1] (1,2)

: Fan, Chengyan, Lin Liu, Zhuoyi Zhao and Cuicui Mu. “Unwrapping errors matter: Pronounced underestimation of surface deformation over Tibetan Plateau permafrost by Sentinel-1 InSAR and its correction”.