Project

Although significant advances have been made in characterizing them, further investigation is needed to address key research challenges in terms of atmospheric science, ocean science, climate change, and space science and technology. 

However, and although an attractive area of research, the oceans remain a challenging field of research, mainly due to: a) their vast extension of water with several kilometers in depth; b) the prohibitive cost of exploration, either by air or by sea; c) the harsh environmental conditions to which vehicles and equipment are exposed in the ocean withstand due to wave action, pressure and corrosion.

Although satellites have been gathering meaningful data regarding the exploration of both oceans and atmosphere, this solution is not without limitations:

1) satellite instruments are generally limited to discrete broad range analysis, not allowing for continuous measurements or precision/detailed analysis of a specific area in the ocean/atmosphere; 2) it is difficult to obtain reliable data on the ocean floor topology and its constitution with satellite-based instrumentation; 3) currently, it is difficult to capture atmospheric and oceanic data within the same vertical column, which would allow to correlate temporal atmospheric and oceanic effects; and 4) even measurements that are currently captured by satellite technology, such as sea surface temperature, require information provided by buoys and drifters to ensure they are accurate and unaffected by dust or other elements in the atmosphere.

This project intends to contribute to a better atmospheric and oceanic monitoring by proposing the development of a complementary system to the existing observation means. This system is two-fold and brings innovation in the respective vectors: (i) the probes and (ii) the probes’ carrier. Regarding the probes, the innovation is relative to their ability to continuously monitor parameters of interest from the near space to the deep sea. The probes will be customizable allowing the integration of atmospheric sensors, motion sensors and marine sensors. When the probe reaches the bottom of the deep sea, it will remain there for a predefined period monitoring all variables plus soundscape from the ground. It will then return to the surface transmitting the data to a ground control station through a satellite or other available communication link, operating as a drift until it stops functioning due to material degradation.

Regarding the probes’ carrier, a high-altitude balloon will be used. This low-cost solution with high cargo capability travels passively through the atmosphere to reach targeted areas, but with low positional accuracy. In the scope of this project, we intend to develop a control solution to endow the aerostat with some positioning capability, by controlling its altitude in agreement with the available wind currents. Limiting the HAB rise will also allow to keep it aloft for longer periods of time, making it not only an excellent atmospheric monitor but also a communications relay between the probes launched in desired locations and a ground control station, reducing the usual satellites communication costs.

A case study of application of SONDA is the measurement of atmospheric CO2 vertical profiles in open ocean environments. Measurements of the CO2 vertical profile in the troposphere is essential because the uncertainties in the estimated fluxes, using inverse methods, can be attributed to the inaccurate representations of the atmospheric processes in transport models.

For demonstration in oceans’ monitoring, hydrophones will be launched in the Azores platform. These sensors will be installed at depths up to 2km and will collect data on the region’s sound activity, which will later be crossed with data on the geological activity recorded by the IVAR network.

The proposed SONDA system, composed of HAB + swarm of probes, will allow the acquisition of data otherwise unreachable in a cost-effective and integrated manner, from near-space to deep-sea. The HAB platform will be capable of deploying disposable probes over hundreds of kilometers, at significant altitudes, something unachievable by other technologies, such as the commonly named drones. This solution also bridges the existing gap between space and surface instrumentation, adding to the available satellite information the detailed long-term analysis of targeted areas.