HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Access-Control-Request-Methods: GET, HEAD, OPTIONS
Content-Length: 97316
Content-Security-Policy: default-src 'self' data: blob:; script-src 'self' 'unsafe-eval' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; worker-src 'self' 'unsafe-eval' 'unsafe-inline' data: blob:; frame-src https:; img-src data: https:; media-src https:; object-src 'none'; sandbox allow-downloads allow-forms allow-modals allow-pointer-lock allow-popups allow-presentation allow-same-origin allow-scripts;
Content-Type: text/xml; charset=utf-8
Last-Modified: Mon, 31 Mar 2025 13:06:42 GMT
Vary: Accept-Encoding
Date: Mon, 26 Jan 2026 15:23:16 GMT
Connection: close


<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="default.xsl"?>
<fr:tree
toc="true"
numbered="true"
show-heading="true"
show-metadata="true"
expanded="true"
root="true"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>362</fr:anchor><fr:addr
type="user">ocs-0001</fr:addr><fr:route>index.xml</fr:route><fr:title
text="Owen">Owen</fr:title><fr:authors><fr:author>owensmith</fr:author></fr:authors><fr:meta
name="author">false</fr:meta></fr:frontmatter><fr:mainmatter><fr:p>I am a <fr:em>Scientific Software Developer</fr:em> for <fr:link
type="external"
href="https://www.earthdata.nasa.gov/centers/gesdisc-daac">NASA Goddard's Earth Sciences Data Information Services Center</fr:link> and a <fr:em>Ph.D. Candidate</fr:em> in <fr:link
type="external"
href="https://cnr.ncsu.edu/geospatial/">Geospatial Analytics @ NCSU</fr:link>.
You can also find me elsewhere at <fr:link
type="external"
href="https://bsky.app/profile/bean.computer">bsky</fr:link>, <fr:link
type="external"
href="https://git.sr.ht/~obeancomputer/">sourcehut</fr:link>, <fr:link
type="external"
href="https://github.com/ocsmit">github</fr:link>.</fr:p><fr:p>This website is built using <fr:link
type="external"
href="https://www.forester-notes.org/index.xml">Forester</fr:link> and is used to collect various notes. You can search the site using <fr:code>ctrl+k</fr:code></fr:p><fr:tree
toc="true"
numbered="true"
show-heading="true"
show-metadata="false"
expanded="false"
root="false"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>361</fr:anchor><fr:addr
type="user">ocs-0002</fr:addr><fr:route>ocs-0002.xml</fr:route><fr:title
text="Notes">Notes</fr:title><fr:authors /></fr:frontmatter><fr:mainmatter><fr:p>This is a notebook in which I keep notes of a variety of subjects at varying degrees of disjointedness.</fr:p><fr:tree
toc="false"
numbered="false"
show-heading="true"
show-metadata="true"
expanded="false"
root="false"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>256</fr:anchor><fr:addr
type="user">ocs-0006</fr:addr><fr:route>ocs-0006.xml</fr:route><fr:title
text="Double Logistic Greendown Model">Double Logistic Greendown Model</fr:title><fr:taxon>Note</fr:taxon><fr:date><fr:year>2025</fr:year><fr:month>3</fr:month><fr:day>20</fr:day></fr:date><fr:authors /></fr:frontmatter><fr:mainmatter><fr:p>Logistic sigmoid function for modeling <fr:link
type="local"
href="ocs-0007.xml"
addr="ocs-0007"
title="Phenology">Phenology</fr:link> detailed in <fr:link
type="local"
href="elmore_ea_2011.xml"
addr="elmore_ea_2011"
title="Landscape controls on the timing of spring, autumn, and growing season length in mid-Atlantic forests">Elmore et. al 2011</fr:link> &amp; <fr:link
type="local"
href="gao_ea_2021.xml"
addr="gao_ea_2021"
title="Long-term, medium spatial resolution annual land surface phenology with a Bayesian hierarchical model">Gao et al. 2011</fr:link>. The function combines spring and autumn seasons into a single equation to account for the <fr:strong>greendown</fr:strong> phenomena by allowing for a gradual reduction of VI values in mid-summer. Typically the model is fit to all VI observations within a single year using maximum likelihood methods.</fr:p><fr:tex
display="block"><![CDATA[ 	v(t, M) = m_1 + (m_2 - m_7t)\left (\frac {1}{1+e^{(m_3-t)/m_4}}-\frac {1}{1 + e^{(m_5-t)/m_6}}\right ) ]]></fr:tex><fr:p>	where
		<fr:ul><fr:li><fr:tex
display="inline"><![CDATA[v(t,m)]]></fr:tex> is the modeled VI value at time <fr:tex
display="inline"><![CDATA[t]]></fr:tex> in terms of day of year (DOY)</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[M = [m_1, \dots  , m_7]^T]]></fr:tex> is a parameter vector controlling the shape of the double-logistic function.</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[m_1]]></fr:tex> represents the mean VI value in the dormant period;</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[(m_2 − m_7t)]]></fr:tex> represents the <fr:strong>difference</fr:strong> between VI value at time <fr:tex
display="inline"><![CDATA[t]]>

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Access-Control-Request-Methods: GET, HEAD, OPTIONS
Content-Length: 97316
Content-Security-Policy: default-src 'self' data: blob:; script-src 'self' 'unsafe-eval' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; worker-src 'self' 'unsafe-eval' 'unsafe-inline' data: blob:; frame-src https:; img-src data: https:; media-src https:; object-src 'none'; sandbox allow-downloads allow-forms allow-modals allow-pointer-lock allow-popups allow-presentation allow-same-origin allow-scripts;
Content-Type: text/xml; charset=utf-8
Last-Modified: Mon, 31 Mar 2025 13:06:42 GMT
Vary: Accept-Encoding
Date: Mon, 26 Jan 2026 15:23:16 GMT
Connection: close


<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="default.xsl"?>
<fr:tree
toc="true"
numbered="true"
show-heading="true"
show-metadata="true"
expanded="true"
root="true"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>362</fr:anchor><fr:addr
type="user">ocs-0001</fr:addr><fr:route>index.xml</fr:route><fr:title
text="Owen">Owen</fr:title><fr:authors><fr:author>owensmith</fr:author></fr:authors><fr:meta
name="author">false</fr:meta></fr:frontmatter><fr:mainmatter><fr:p>I am a <fr:em>Scientific Software Developer</fr:em> for <fr:link
type="external"
href="https://www.earthdata.nasa.gov/centers/gesdisc-daac">NASA Goddard's Earth Sciences Data Information Services Center</fr:link> and a <fr:em>Ph.D. Candidate</fr:em> in <fr:link
type="external"
href="https://cnr.ncsu.edu/geospatial/">Geospatial Analytics @ NCSU</fr:link>.
You can also find me elsewhere at <fr:link
type="external"
href="https://bsky.app/profile/bean.computer">bsky</fr:link>, <fr:link
type="external"
href="https://git.sr.ht/~obeancomputer/">sourcehut</fr:link>, <fr:link
type="external"
href="https://github.com/ocsmit">github</fr:link>.</fr:p><fr:p>This website is built using <fr:link
type="external"
href="https://www.forester-notes.org/index.xml">Forester</fr:link> and is used to collect various notes. You can search the site using <fr:code>ctrl+k</fr:code></fr:p><fr:tree
toc="true"
numbered="true"
show-heading="true"
show-metadata="false"
expanded="false"
root="false"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>361</fr:anchor><fr:addr
type="user">ocs-0002</fr:addr><fr:route>ocs-0002.xml</fr:route><fr:title
text="Notes">Notes</fr:title><fr:authors /></fr:frontmatter><fr:mainmatter><fr:p>This is a notebook in which I keep notes of a variety of subjects at varying degrees of disjointedness.</fr:p><fr:tree
toc="false"
numbered="false"
show-heading="true"
show-metadata="true"
expanded="false"
root="false"
xmlns:fr="http://www.jonmsterling.com/jms-005P.xml"><fr:frontmatter><fr:anchor>256</fr:anchor><fr:addr
type="user">ocs-0006</fr:addr><fr:route>ocs-0006.xml</fr:route><fr:title
text="Double Logistic Greendown Model">Double Logistic Greendown Model</fr:title><fr:taxon>Note</fr:taxon><fr:date><fr:year>2025</fr:year><fr:month>3</fr:month><fr:day>20</fr:day></fr:date><fr:authors /></fr:frontmatter><fr:mainmatter><fr:p>Logistic sigmoid function for modeling <fr:link
type="local"
href="ocs-0007.xml"
addr="ocs-0007"
title="Phenology">Phenology</fr:link> detailed in <fr:link
type="local"
href="elmore_ea_2011.xml"
addr="elmore_ea_2011"
title="Landscape controls on the timing of spring, autumn, and growing season length in mid-Atlantic forests">Elmore et. al 2011</fr:link> &amp; <fr:link
type="local"
href="gao_ea_2021.xml"
addr="gao_ea_2021"
title="Long-term, medium spatial resolution annual land surface phenology with a Bayesian hierarchical model">Gao et al. 2011</fr:link>. The function combines spring and autumn seasons into a single equation to account for the <fr:strong>greendown</fr:strong> phenomena by allowing for a gradual reduction of VI values in mid-summer. Typically the model is fit to all VI observations within a single year using maximum likelihood methods.</fr:p><fr:tex
display="block"><![CDATA[ 	v(t, M) = m_1 + (m_2 - m_7t)\left (\frac {1}{1+e^{(m_3-t)/m_4}}-\frac {1}{1 + e^{(m_5-t)/m_6}}\right ) ]]></fr:tex><fr:p>	where
		<fr:ul><fr:li><fr:tex
display="inline"><![CDATA[v(t,m)]]></fr:tex> is the modeled VI value at time <fr:tex
display="inline"><![CDATA[t]]></fr:tex> in terms of day of year (DOY)</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[M = [m_1, \dots  , m_7]^T]]></fr:tex> is a parameter vector controlling the shape of the double-logistic function.</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[m_1]]></fr:tex> represents the mean VI value in the dormant period;</fr:li>
			<fr:li><fr:tex
display="inline"><![CDATA[(m_2 − m_7t)]]></fr:tex> represents the <fr:strong>difference</fr:strong> between VI value at time <fr:tex
display="inline"><![CDATA[t]]>

HTTP/1.1 302 Moved Temporarily
Server: nginx
Date: Mon, 26 Jan 2026 15:23:15 GMT
Content-Type: text/html
Content-Length: 138
Connection: close
Location: https://bean.computer/

Page title: 302 Found

<html>
<head><title>302 Found</title></head>
<body>
<center><h1>302 Found</h1></center>
<hr><center>nginx</center>
</body>
</html>

HTTP/1.1 302 Moved Temporarily
Server: nginx
Date: Mon, 26 Jan 2026 15:23:12 GMT
Content-Type: text/html
Content-Length: 138
Connection: close
Location: https://bean.computer/

Page title: 302 Found

<html>
<head><title>302 Found</title></head>
<body>
<center><h1>302 Found</h1></center>
<hr><center>nginx</center>
</body>
</html>