Water quality instruments

LIFL.11 mounted on a vessel rail with open sea behind
Survey

LIFL-11

The LIFL-11 combines laser-induced fluorescence, elastic scattering, and Raman scattering in one survey instrument. It records the full 48-band return in about fifteen seconds at a station or measures four selected bands at up to 10 Hz while underway. Two excitation configurations cover chlorophyll, CDOM, suspended matter, oils, phenols, and tryptophan.

What it measures
  • Phytoplankton and pigments Measures chlorophyll-a from 0.01 to 1000 mg·m⁻³ and distinguishes pigment returns associated with phycoerythrin and phycocyanin
  • Dissolved organic matter Characterises CDOM and FDOM, including fulvic and humic matter and optical markers associated with wastewater
  • Hydrocarbons and oil Uses 266 nm excitation to distinguish fluorescence from fuels, diesel, crude oil, and oil-in-water emulsions
  • Marine litter and plastics Records fluorescence signatures from polyethylene, polypropylene, wood, leaves, seagrass, and surface foam
  • Suspended matter Maps mineral particles and suspended sediment from 0.1 to 1000 g·m⁻³ along the survey track
  • Additional spectral signals Phycoerythrin, phycocyanin, bacteriochlorophyll, tryptophan and phenol markers, and methane seep signatures
Key specifications
Total bands
48, ~250–800 nm
Excitation
355 + 532 nm or 266 + 532 nm
Repetition rate
up to 10 Hz
Chl-a range
0.01–1000 mg·m⁻³
Surface-layer sensing
0.5–5 m @355 nm, 1–10 m @532 nm
Size / mass
44 × 33 × 28 cm, 21 kg
Deployment platforms
Research vesselSmall vessel / RIBFerry of opportunityAutogyro / small aircraftFixed coastal stationUSV
mFL.12 sensor render from the OQOMETHI poster
Unattended

mFL-12

Unattended above-water fluorescence measurements in a 1.75 kg instrument

The mFL-12 is installed above the water for unattended fluorescence measurements at user-defined intervals. A modulated 405 nm source and a 400–880 nm receiver separate the laser-induced signal from ambient light, allowing operation by day or night. Measurements can be transmitted to the Microsensor Viewer for processing, quality control, and review. The instrument is at TRL 7–8 and was field-tested during ESA's PHY2FLEX campaign in Venice in 2025.

What it measures
  • Chlorophyll-a and CDOM Estimates chlorophyll-a and CDOM concentration from a fixed or moving surface platform
  • Total suspended matter Estimates total suspended matter at outfalls, river mouths, port basins, and monitoring stations
  • Petroleum Detects surface films and oil-in-water emulsions from an above-water installation
  • Ambient-light rejection Alternating laser-on and laser-off measurements isolates the fluorescence signal for day-and-night operation
Key specifications
Excitation
405 nm, single, modulated
Reception
hyperspectral, 400–880 nm, 288 bands
Detection rate
up to 1 Hz, ambient-light dependent
Size / mass
130 × 140 × 121 mm, 1.75 kg
Deployment platforms
Moored buoyPier / bridgeVesselUSVFixed coastal station
mHR.2 radiometer mounted on a metal support above the water
Passive

mHR-2

Above-water Rrs measurements for satellite comparison and water-colour monitoring

The mHR-2 is a passive radiometer with one motorised head for downwelling irradiance, sky radiance, sea-surface radiance, and dark-current measurements. Each cycle returns Rrs across 320–880 nm together with position, attitude, and a context image. The instrument was developed through OQOMETHI and field-tested during ESA's PHY2FLEX campaign in Venice in 2025.

What it measures
  • Above-water Rrs Combines downwelling irradiance, sky radiance, and sea-surface radiance with a dark-current measurement in each cycle
  • Satellite match-up Returns Rrs for synchronous comparison with satellite observations and active LIF measurements
  • Sun-glint rejection Uses the standard 40° sky and 140° sea-surface viewing geometry, measured from zenith, to minimise sun glint
  • Autonomous operation Runs unattended and can upload measurement records automatically for remote review
Key specifications
Channels
3, Ed, Ls, Lt
Output
Rrs (remote-sensing reflectance)
Wavelength range
320–880 nm
Size / mass
132 × 125 × 106 mm, 0.9 kg
Deployment platforms
VesselSmall vessel / RIBPier / bridgeMoored buoyFixed coastal station
Datasheets

Specifications for each instrument

Public datasheets are listed here; operating and integration documents are supplied with the instrument or on request