Water reflectance sensor observation instruments

NEODAAS provides autonomous instrumentation for measurement of above-water reflectance. The service includes remote installation support and data processing.


The Solar-tracking Radiometry (So-Rad) platform

Measurements of above-water reflectance are critical to monitor aquatic ecosystems and validate satellite ocean colour data. To facilitate data reflectance data collection, NEODAAS provides the solar-tracking radiometry platform (So-Rad) as a request service to UK-based researchers for medium and long term deployments (in the order of months up to a year). So-Rad is a high-end, autonomous system where the optical sensors rotate to maintain optimal viewing angles, avoiding sun glint and platform shading. The system is specifically designed for operation on ships and data are automatically transferred to a data processing backend at PML, from where they are shared under an open data license. The local operator is only required to periodically clean the optical sensors. An overview of So-Rad is provided here:


Figure 1. Each So-Rad system consists of two radiometers mounted on a rotating axle and a downwelling irradiance sensor mounted separately from the other sensors (right of the figure). Spectral measurements from the three sensors are combined to produce water reflectance.

Installation and NEODAAS request procedure

So-Rad is suitable for deployment on ships, large buoys and fixed platforms. Each installation consists of attaching a control unit, motor enclosure, sensors, data and power cables, and two GNSS antennas. So-Rad systems can be requested by researchers eligible for NERC funding via the application form which is subject to peer review: The form also assesses the technical feasibility of the planned deployment. For inclusion on NERC grants, support should be requested when the proposal is submitted in the form of a technical assessment, please contact NEODAAS for details on this.

Data processing and access

As part of the service, data from So-Rad are automatically processed in near real-time and made available through a data analysis package and dedicated data services.  dashboard to monitor data collection in the field:
Figure 2. Example of water remote-sensing reflectance spectra collected by So-Rad along a transect from the open sea (cyan) to Plymouth Harbour (pink).