altimetryFit

Scripts for fitting smooth surfaces to altimetry data

This repository includes code that uses the utilities in the smithB/LSsurf and smithB/pointCollection repos to fit smoothly changing surfaces to altimetry data from Greenland and Antarctica.

A sample workflow for this repository is:

1. Download altimetry files:

Supported formats include:

- ICESat hdf5
- ICESat-2 ATL06, ATL11 
- Reduced ATM Qfit (see scripts/reduce_ATM.py)
- Reduced LVIS
- Reduced PGC DEMs (see scripts/dem_filter.py)
- Cryosat-2 level-2
- Retracked Cryosat-2 level-1

Each datatype should be stored in its own directory

2. Use the pointCollection index_glob.py script to create a geoIndex file for each altimetry-file directory

3. Create a json file containing a list of geoIndex files:

The json file should translate to a Python dictionary, in which the keys are the data types, and  the values are the corresponding geoIndex filenames, or wildcards that reduce to a list of geoIndex filenames

Example (default_args/Arctic_GI_files_IS2_era.json) :

{
    "ICESat2": "/Volumes/ice1/ben/ATL06/tiles/Arctic/005/*/GeoIndex.h5",
    "DEM": "/Volumes/insar10/ben/ArcticDEM/v2*/*/GeoIndex.h5"
}

4. Create a default_args file containing arguments to fit_altimetry.py

Example ()

5. Generate tiled preliminary fits

The preliminary fits produce independent tiles of fit data (e.g. 30x30-km tiles, with centers spaced 20 km apart). These can be mosaicked directly, or if distracting discontinuities are visible between tiles, step 6 allows matching at tile boundaries.

scripts/make_OIB_queue.py with the --prelim argument generates commands to make tiles that span the area defined by the --mask_file argument in the default_args file, in steps of the --tile_spacing argument

Run the commands in the preliminary queue, with xargs or using scripts in the smithB/parallel_boss repo.

6. Rerun the tiles, with forced edge matching

Run scripts/make_OIB_queue.py with the --matched argument, and run that list of commands.

7. Mosaic the output.

scripts/regen_OIB_mosaics will generate mosaics of the dz and z0 fields from the tiles.