ShapeSelectForest - Shape Selection for Landsat Time Series of Forest Dynamics
Landsat satellites collect important data about global
forest conditions. Documentation about Landsat's role in forest
disturbance estimation is available at the site
<https://landsat.gsfc.nasa.gov/>. By constrained quadratic
B-splines, this package delivers an optimal shape-restricted
trajectory to a time series of Landsat imagery for the purpose
of modeling annual forest disturbance dynamics to behave in an
ecologically sensible manner assuming one of seven possible
"shapes", namely, flat, decreasing, one-jump (decreasing, jump
up, decreasing), inverted vee (increasing then decreasing), vee
(decreasing then increasing), linear increasing, and
double-jump (decreasing, jump up, decreasing, jump up,
decreasing). The main routine selects the best shape according
to the minimum Bayes information criterion (BIC) or the cone
information criterion (CIC), which is defined as the log of the
estimated predictive squared error. The package also provides
parameters summarizing the temporal pattern including year(s)
of inflection, magnitude of change, pre- and post-inflection
rates of growth or recovery. In addition, it contains routines
for converting a flat map of disturbance agents to time-series
disturbance maps and a graphical routine displaying the fitted
trajectory of Landsat imagery.
