DOI: 10.6078/d1zt1m
title: Restoration of incomplete oceanographic datasets

description: Remote sensing of oceanographic data often yields incomplete coverage of
 the measurement domain. This can limit interpretability of the data and
 identification of coherent features informative of ocean
 dynamics. Several methods exist to fill gaps of missing
 oceanographic data, and are often based on projecting the
 measurements onto basis functions or a statistical model. Herein, we use
 an information transport approach inspired from an image processing
 algorithm. This approach aims to restore gaps in data by advecting and
 diffusing information of features as opposed to the field itself.
 Since this method does not involve fitting or projection, the portions of
 the domain containing measurements can remain unaltered, and the method
 offers control over the extent of local information transfer. This method
 is applied to measurements of ocean surface currents by high frequency
 radars. This is a relevant application because data coverage can be
 sporadic and filling data gaps can be essential to data usability.
 Application to two regions with differing spatial scale is considered. The
 accuracy and robustness of the method is tested by systematically blinding
 measurements and comparing the restored data at these locations to the
 actual measurements. These results demonstrate that even for locally large
 percentages of missing data points, the restored velocities have errors
 within the native error of the original data (e.g., &lt;10% for
 velocity magnitude and &lt;3% for velocity direction). Results were
 relatively insensitive to model parameters, facilitating a
 priori selection of default parameters for de
 novo applications. 
description: Input Data: There are four files in this
 dataset. Two file are original measurments of ocean surface velocity
 obtained from High Frequency radars. 
 <pre> HFR_MarthaVineyard_2014_original.nc</pre> 
 <pre> HFR_MontereyBay_2017_original.nc</pre>
 The above NetCDF files contain east and
 north velocity fields at two sites.The dataset at Martha's Vineyard,
 Massachussetts, is collected by HF radar operated by Woods Hole
 Oceanographic Institue (WHOI). The dataset has 400m resolution and covers
 July to September of 2014. The dataset at Monterey Bay, California has 2km
 resolution spanning a larger domain and covers January of 2017. Both
 datasets are publically availble  Output
 Data: These data have incomplete coverage. With our
 method, we have resotored the missing coverage. The output files of our
 method are: <pre>
 HFR_MarthaVineyard_2014_restored.nc</pre> 
 <pre> HFR_MontereyBay_2017_restored.nc</pre> 
 Visualization of data: The above
 datasets can be interactively visualized online at the following
 links: Original Martha's Vineyard
 data: http://transport.me.berkeley.edu/terriajs/#clean&WHOI_HFR_2014_original Restored Martha's Vineyard data: http://transport.me.berkeley.edu/terriajs/#clean&WHOI_HFR_2014_restored Original Monterey Bay data: http://transport.me.berkeley.edu/terriajs/#clean&MontereyBay_2km_original Restored Monterey Bay data: http://transport.me.berkeley.edu/terriajs/#clean&MontereyBay_2km_restored
description: Online software: We have developed a
 web-based gateway to accompany our manuscript available at http://transport.me.berkeley.edu/restore/ and has been designed to be a community tool to process incomplete oceanographic datasets. The gateway contains a user guide, documentation and sample data, including those that has been used in this manuscript. Demo video: A brief video of the tool is demonstrated at https://vimeo.com/274810038. All results of this manuscript can be reproduced using our online tool.