D4.1 Report on performance criteria for field testing. Deliverable report of project H2020 MONOCLE (grant 776480)

This document constitutes Deliverable 4.1 of the MONOCLE project and provides an overview of the key performance indicators (KPIs) for each sensor or system as defined at the start of the project, briefly summarised as follows.

Prosumer units of a Remote Piloted Aircraft System (RPAS), either DJI Phantom 4 pro or DJI M200,  equipped with a range of cameras (RBG, Micasense Red-edge or Multispectral) are intended to be deployed by professionals and citizen science groups. These sensors measure radiance of the water surface and convert this to water-leaving reflectance, which will be validated by a TriOS Ramses, ASD Field Spec or WISP system. Concentrations of total suspended matter (TSM) and chlorophyll-a (Chl-a) derived from the camera imagery will be validated against laboratory measurements. Target measurement precision and performance accuracy for all parameters will be tested and are expected to depend on illumination conditions.

The HSP1 is a fixed installation that will collect global and diffuse irradiance measurements, to be validated against a sun photometer (e.g. Cimel) in the field. Measurement precision is in the range of 3-5%, while target performance accuracy is 5% uncertainty/offset.

The CLAM is presently a bench top flow-through system which measures in situ Chl-a concentrations.  Measurements will be validated against accredited laboratory analysis of Chl-a (e.g. High Performance Liquid Chromatography (HPLC)).  Measurement range and precision are to be tested and feed back into the development cycle, while target performance accuracy will be 10% uncertainty/offset.

The sun tracking radiometer platform is a ship-mounted device for control of the azimuth viewing angle of radiometers with respect to the sun and ship heading.  Reference values can be calculated from ship compass and solar position. Measurement precision is 1°, while target performance accuracy is <1% uncertainty assuming the viewing angle is consistently >90° and a ship heading is available.

The iSPEX is a smartphone add-on for citizen science measurements of aerosol optical thickness (AOT), which will be adapted for MONOCLE to measure water colour.  Measurements of AOT will be validated against groundSPEX, MODIS or AERONET measurements.  AOT measurement precision is >5% per individual measurement and <1% when stacking >50 measurements, and target performance accuracy is <10% uncertainty/offset. 

The KdUINO is a profiling device from a surface buoy that measures the light extinction coefficient (K_d).  It will be adapted for MONOCLE with a new sensor and hardware, improved accuracy and temperature sensors.  Measurements will be validated in the laboratory against TriOS radiometers, and precision and accuracy will be defined during the MONOCLE campaigns to feed back into the development cycle.

The WISPStation is a fixed installation which measures remote sensing reflectance (R_rs(l)). Measurements will be validated against other high-end calibrated field spectroradiometers (e.g. TriOS Ramses). Measurement precision is 2%, depending on the ambient light and wave conditions) and target performance accuracy will be determined during the MONOCLE campaigns.

FreshWater Watch is an established citizen science method for monitoring of global freshwaters, which includes assessments of water colour, turbidity (Secchi tubes) and colourimetric phosphate measurement using inosine enzymatic reactions.  Phosphate measurements will be validated in the laboratory (Skalar SAN++ system autoanalyzer with ammonium molybdate). Measurement precision is 43% (Relative Standard Deviation - to be confirmed) and performance accuracy will be defined during the MONOCLE campaigns.

The system KPIs described in this deliverable will inform planning of the forthcoming MONOCLE field campaigns as well as the novel development activities (WP2 & WP3) and innovation activities (WP5, WP6 & WP7).