Knowledge Base

What is the difference between the NASA Team algorithm and the Bootstrap algorithm?

For general analyses or creation of simple images, either algorithm will suffice. The Bootstrap sea ice concentration data set is believed to be more useful for modeling and process studies in the polar regions because it is generally free of residual errors that could not be removed by conventional techniques. A temporally more consistent time series of sea ice concentrations is provided, offering improved accuracy over the ice concentration maps created from the original Bootstrap algorithm.

For in-depth analyses, input into model fields or other scientific research, users should first study the differences between the algorithms. For more information, see the NASA Team and Bootstrap algorithm descriptions.

NASA Team Bootstrap
Channels 19V, 19H, 37V Frequency mode: 19V, 37V (seasonal ice)
Polarization mode: 37V, 37H (perennial ice)
Methodology Ratios of brightness temperatures Interpolation between clusters of pure ice types
Tiepoints Summer and winter only Multi-seasonal
Strengths Not sensitive to changes in surface temperature Less sensitive to thin ice and layering within snow and ice
Weaknesses Sensitive to thin ice and layering within snow and ice Sensitive to changes in temperature (thin ice); tiepoints switch by date.
Regions of
highest errors
Regions where melt or refreeze occurs; algorithm underestimates thin ice Regions with very cold surface temperatures, such as the Antarctic coast in winter and central Arctic in winter

 Last Updated February 2018