{"id":371867,"date":"2026-02-19T05:23:57","date_gmt":"2026-02-18T19:23:57","guid":{"rendered":"https:\/\/science.nasa.gov\/missions\/explorer\/notes-from-the-field\/"},"modified":"2026-02-19T05:23:57","modified_gmt":"2026-02-18T19:23:57","slug":"notes-from-the-field","status":"publish","type":"post","link":"https:\/\/www.vibewire.com.au\/?p=371867","title":{"rendered":"Notes from the Field"},"content":{"rendered":"
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2 min read<\/p>\n

Notes from the Field<\/h1>\n<\/div>\n<\/div>\n<\/div>\n

Looking at Chlorophyll from Space<\/h3>\n

By Compton \u201cJim\u201d Tucker<\/h5>\n
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\"Tucker<\/a><\/figure>
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Tucker began his ground studies using a handheld instrument built by one of his classmates. \u201cThe instrument was literally held together by masking tape and rubber bands.\u201d<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

NASA scientists are able to study plants from space, but this wasn\u2019t always the case.<\/p>\n

\u201cI love using satellite data to study the Earth,\u201d says Dr. Compton \u201cJim\u201d Tucker. When Tucker was a graduate student, he and some friends discovered a new way to study photosynthesis.<\/p>\n

\u201cWe realized that there was a really strong connection with the plant pigment, chlorophyll, and certain wavelengths of light. We figured out that if you wanted to study photosynthesis you needed to study chlorophyll.\u201d<\/p>\n

Tucker learned that you could figure out plant health by measuring how much visible and near-infrared light a plant reflects. \u201cWe call this light-type comparison the Normalized Differentiated Vegetation Index (NDVI). Really it is just a simple ratio of these two wavelengths or bands.\u201d<\/p>\n

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\"Tucker<\/a><\/figure>
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Tucker in 1971. Tucker first became interested in the world around him and began to look at it more closely when a friend\u2019s older brother took them both exploring around the Pecos River in New Mexico. \u201cHe really helped to raise my awareness and my interest in the natural wonders of Earth. I really enjoy doing field work.\u201d<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

This was groundbreaking science. Tucker also learned that this observation and comparison could be done from space. In 1981 the first NDVI instrument flew in space as part of the Advanced Very High Resolution Radiometer (AVHRR) mission. \u201cIt is the same instrument from my working-in-the-field days, literally, just bigger.\u201d<\/p>\n

Later in 1983, Tucker met Piers Sellers. This meeting began a decades-long friendship and scientific collaboration. Sellers came up with a way to scale Tucker\u2019s photosynthesis measurements. This made it possible to get detailed information about plant health around the globe \u2014 from a single leaf to plants covering a field, a forest, or a continent and all from space.<\/p>\n

\u201cPeople are always asking me when I plan to retire,\u201d Tucker says. \u201cAnd I always say that I really like what I am doing. I am going to do it for as long as I can because it is fun. Most people look at me and think \u2018Are you crazy?\u2019 I am not. It is true: I really love my work.\u201d<\/p>\n

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About the Author<\/h2>\n
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