> For the complete documentation index, see [llms.txt](https://docs.terraref.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.terraref.org/user-manual/data-products/fluorescence-intensity-imaging.md). # Fluorescence intensity imaging ## Summary Fluorescence intensity data is collected using the PSII camera. Each measurement produces 102 bin files. The first (index 0) is an image taken right before the LED are switched on (dark reference). Frame 1 to 100 are the 100 images taken, with the LEDs on. In binary file 102 (index 101) is a list with the timestamps of each frame of the 100 frames. Right now the LED on timespan is 1s thus the first 50 frames are taken with LEDs on the latter 50 frames with LED off. ![](/files/-MTbNAFIXpLx6XfgNuqo) ![](/files/-MTbN6j48oIg-xb_7CsJ) ## Raw data access Fluorescence intensity data is available via Clowder and Globus: * **Clowder**: \_\_[ps2Top collection](https://terraref.ncsa.illinois.edu/clowder/collection/58714b584f0cc129fb5ea660) * **Globus paths**: * `/raw_data/ps2top` * `/Level_1/ps2_png/` * **Sensor information**: [LemnaTec PSII](https://terraref.ncsa.illinois.edu/clowder/datasets/5873a84b4f0cad7d8131a73d) * **Code on GitHub**: [**Multispectral extractor**](https://github.com/terraref/extractors-multispectral) ## See also Herritt, Matthew T., et al. "Chlorophyll fluorescence imaging captures photochemical efficiency of grain sorghum (Sorghum bicolor) in a field setting." Plant Methods 16.1 (2020): 1-13. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.terraref.org/user-manual/data-products/fluorescence-intensity-imaging.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.