<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Remote Sensing |</title><link>https://AaronScherf.github.io/tags/remote-sensing/</link><atom:link href="https://AaronScherf.github.io/tags/remote-sensing/index.xml" rel="self" type="application/rss+xml"/><description>Remote Sensing</description><generator>HugoBlox Kit (https://hugoblox.com)</generator><language>en-us</language><lastBuildDate>Sat, 22 Aug 2026 00:00:00 +0000</lastBuildDate><image><url>https://AaronScherf.github.io/media/sharing.jpg</url><title>Remote Sensing</title><link>https://AaronScherf.github.io/tags/remote-sensing/</link></image><item><title>Predicting Wheat Yields in New Environments</title><link>https://AaronScherf.github.io/projects/wheat_yield_prediction/</link><pubDate>Sat, 22 Aug 2026 00:00:00 +0000</pubDate><guid>https://AaronScherf.github.io/projects/wheat_yield_prediction/</guid><description>&lt;p&gt;Choosing a wheat variety is partly a question of where it will grow. My master&amp;rsquo;s thesis tested whether satellite measurements of the environment and accessible machine learning tools could help predict yields where field-trial information is limited. I compared those measurements with field records, using wheat trials from CIMMYT, an international crop-research organization.&lt;/p&gt;
&lt;p&gt;The results separated two questions that can easily get mixed together. Machine learning models outperformed the study&amp;rsquo;s linear mixed-model baseline on held-out observations. Satellite data helped that baseline, but the machine learning models performed better with the manually collected environmental data. A stronger model and a more accessible data source did not automatically make the best combination.&lt;/p&gt;
&lt;h2 id="what-was-compared"&gt;What was compared&lt;/h2&gt;
&lt;p&gt;Google Earth Engine supplied environmental measurements such as soil moisture, precipitation, and vapor pressure. Field records supplied another view of growing conditions and management. I also tested adding pedigree information describing relationships between wheat varieties.&lt;/p&gt;
&lt;p&gt;Four approaches predicted yields: a Bayesian linear mixed model, random forest, gradient boosting, and a neural network. Fifteen percent of observations were held out for the final comparison, with varieties represented across that sample. This tests predictions within the study&amp;rsquo;s data; use in new regions would need further validation.&lt;/p&gt;
&lt;p&gt;For a direct comparison using environmental data alone:&lt;/p&gt;
&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Environmental information&lt;/th&gt;
&lt;th&gt;Random forest R²&lt;/th&gt;
&lt;th&gt;Linear mixed-model R²&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Field records&lt;/td&gt;
&lt;td&gt;0.829&lt;/td&gt;
&lt;td&gt;0.113&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Satellite-derived data&lt;/td&gt;
&lt;td&gt;0.746&lt;/td&gt;
&lt;td&gt;0.243&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p&gt;R² measures how much of the variation in the held-out yields the predictions account for relative to predicting the average. It is not the percentage accuracy of an individual yield prediction. The
gives the full comparison, including pedigree information.&lt;/p&gt;
&lt;h2 id="accessibility-mattered-too"&gt;Accessibility mattered too&lt;/h2&gt;
&lt;p&gt;The machine learning models ran on freely available Google Colab resources, though some calculations took hours. The mixed model&amp;rsquo;s large genetic covariance matrices required a specialized machine with roughly a terabyte of memory. Computing requirements were therefore part of the comparison, alongside prediction quality.&lt;/p&gt;
&lt;p&gt;The code is public, but restricted pedigree data prevents full reproduction from public inputs alone. The project is a research proof of concept, with further work needed on location precision, model settings, and validation before using its predictions to make planting decisions.&lt;/p&gt;
&lt;p&gt;This was my Spring 2020 thesis for UC Berkeley&amp;rsquo;s Master of Development Practice, advised by Professor David Zilberman. The
contains the code and full report.&lt;/p&gt;</description></item></channel></rss>