Solar-tracking radiometry for all: PML publishes open-source hardware and software for the solar-tracking radiometry platform (So-Rad).
Observing water colour (reflectance) allows researchers to assess the presence of phytoplankton, suspended solids and dissolved organic matter in inland, coastal and ocean waters. The automated, open-source So-Rad (solar-tracking radiometry) platform significantly lowers the cost of collecting ground truth to validate these observations made by satellites.
One of the best ways to increase the volume of useful water-leaving reflectance observations is to mount radiometers on a turning platform. Thus far only experimental and closed-source commercial solutions existed, neither of which were sufficient to achieve the ambition of delivering continuous, quality-controlled satellite validation data around the world.
With the So-Rad, PML provides owners of commercially available radiometers the possibility to upgrade fixed-angle systems. A step-by-step build guide is now available through the So-Rad page on the MONOCLE website. The build guide includes hardware and software components including CAD diagrams for both electronics and machining. All materials are published under a Creative Commons Attribution-Non-Commercial license.
Some key features of the So-Rad include:
- Low power consumption (15W)
- Viewing angle adjustment for solar position and platform heading, suitable for ships and (large) buoys
- Tilt/pitch/roll monitoring
- Local data buffering for fully autonomous operation
- Configurable operating range for viewing angle, solar elevation, and measurement intervals: no need to collect data under suboptimal conditions
- Control software written in Python 3, modular design to extend e.g. additional sensor support
- Local (WiFi) and remote (LTE) monitoring