Hyperspectral sensors are getting more important

 

This article is about the uses of data from the Earth Surface Mineral Dust Source Investigation (EMIT) sensor on the International Space Station, but there are more hyperspectral instruments in space, such as NASA's PACE (Plankton, Aerosol, Cloud, and ocean Ecosystem) mission. 

NASA Space Station Sensor Spots Contamination off the California Coast

Proof-of-concept results from the mouth of the Tijuana River in San Diego County show how an instrument called EMIT could aid wastewater detection.

"That’s where EMIT comes in. NASA’s hyperspectral instrument orbits Earth aboard the International Space Station, observing sunlight reflecting off the planet below. Its advanced optical components split the visible and infrared wavelengths into hundreds of color bands. By analyzing each satellite scene pixel by pixel at finer spatial resolution, scientists can discern what molecules are present based on their unique spectral “fingerprint.”

Scientists compared EMIT’s observations of the Tijuana River plume with water samples they tested on the ground. Both EMIT and the ground-based instruments detected a spectral fingerprint pointing to phycocyanin, a pigment in cyanobacteria, an organism that can sicken humans and animals that ingest or inhale it."

This is a good image from the study:

"Fig. 8. (A) True color EMIT hyperspectral satellite image covering a known wastewater plume on 25 March 2023. (B) Fluorescence Line Height (FLH) at 650 nm calculated from EMIT reflectance imagery. FLH is greatest at the Tijuana River Estuary and decreases with distance from the estuary mouth."

Read all about it:

Reference: Scrivner E, Mladenov N, Biggs T, et al. Hyperspectral characterization of wastewater in the Tijuana River Estuary using laboratory, field, and EMIT satellite spectroscopy. Sci Total Environ. 2025;981:179598. doi: 10.1016/j.scitotenv.2025.179598.