PhenoDeriv

PhenoDeriv.fFIT

PhenoDeriv.default

Phenology extraction in Derivative method (DER)

The merits of 'TIMESAT' and 'phenopix' are adopted. Besides, a simple and
growing season dividing method and a practical snow elimination method
based on Whittaker were proposed. 7 curve fitting methods and 4 phenology
extraction methods were provided. Parameters boundary are considered for
every curve fitting methods according to their ecological meaning.
And 'optimx' is used to select best optimization method for different
curve fitting methods.
Reference:
Kong, D., (2020). R package: A state-of-the-art Vegetation Phenology extraction
package, phenofit version 0.3.1, <doi:10.5281/zenodo.5150204>;
Kong, D., Zhang, Y., Wang, D., Chen, J., & Gu, X. (2020). Photoperiod Explains
the Asynchronization Between Vegetation Carbon Phenology and Vegetation Greenness
Phenology. Journal of Geophysical Research: Biogeosciences, 125(8), e2020JG005636.
<doi:10.1029/2020JG005636>;
Kong, D., Zhang, Y., Gu, X., & Wang, D. (2019). A robust method for reconstructing
global MODIS EVI time series on the Google Earth Engine.
ISPRS Journal of Photogrammetry and Remote Sensing, 155, 13–24;
Zhang, Q., Kong, D., Shi, P., Singh, V.P., Sun, P., 2018. Vegetation phenology
on the Qinghai-Tibetan Plateau and its response to climate change (1982–2013).
Agric. For. Meteorol. 248, 408–417. <doi:10.1016/j.agrformet.2017.10.026>.

Dongdong Kong

phenofit

Extract Remote Sensing Vegetation Phenology

Mingzhong Xiao

Yongqiang Zhang

Xihui Gu

Jianjian Cui

PhenoDeriv function

<dl><dt>x</dt>
<dd>numeric vector, or <code>fFIT</code> object returned by <code>curvefit()</code>.</dd>
<dt>t</dt>
<dd><code>doy</code> vector, corresponding doy of vegetation index.</dd>
<dt>...</dt>
<dd>Other parameters will be ignored.</dd>
<dt>analytical</dt>
<dd>If true, <code>numDeriv</code> package <code>grad</code> and <code>hess</code>
will be used; if false, <code>D1</code> and <code>D2</code> will be used.</dd>
<dt>smoothed.spline</dt>
<dd>Whether apply <code>smooth.spline</code> first?</dd>
<dt>der1</dt>
<dd>the first order difference</dd>
<dt>IsPlot</dt>
<dd>whether to plot?</dd>
<dt>show.legend</dt>
<dd>whether show figure lelend?</dd></dl>

Arguments

Phenology extraction in Derivative method (DER) — PhenoDeriv

<dl>

<dt>x</dt>
<dd>numeric vector, or <code>fFIT</code> object returned by <code>curvefit()</code>.</dd>


<dt>t</dt>
<dd><code>doy</code> vector, corresponding doy of vegetation index.</dd>


<dt>...</dt>
<dd>Other parameters will be ignored.</dd>


<dt>analytical</dt>
<dd>If true, <code>numDeriv</code> package <code>grad</code> and <code>hess</code>
will be used; if false, <code>D1</code> and <code>D2</code> will be used.</dd>


<dt>smoothed.spline</dt>
<dd>Whether apply <code>smooth.spline</code> first?</dd>


<dt>der1</dt>
<dd>the first order difference</dd>


<dt>IsPlot</dt>
<dd>whether to plot?</dd>


<dt>show.legend</dt>
<dd>whether show figure lelend?</dd>

</dl>

PhenoDeriv: Phenology extraction in Derivative method (DER)

Description

Usage

Arguments

References

See Also