Mapping Biodiversity Via Advanced Technologies

Biodiversity Mapping Via Advanced Technologies

The marine and coastal life forms exhibit great diversity, making it an extremely complex system, which is difficult for the space-based monitoring systems to assess. cosine is developing the technology for a constellation of small satellites that provides crucial information for better understanding and monitoring of marine organisms. By Marco Esposito and Marco Beijersbergen, cosine

The North Sea, the tidal areas and the dunes that characterize the Dutch landscape are areas where the original processes of nature have remained relatively intact. Here the marine and coastal life forms exhibit great diversity, making it an extremely complex system that is difficult to assess. Similar habitats that combine high biodiversity with high productivity are distributed globally and need frequent and broad systematic assessments.

A space-based monitoring system can greatly help to take actions based on clear information on the status of biodiversity. Recent developments in advanced optical instruments for space offer the possibility to monitor biodiversity from space much more frequently. cosine is developing the technology for a constellation of small satellites that provide high-frequency hyperspectral and spectropolarimetric measurements, in complement to existing and planned hyperspectral missions from ESA and NASA.

Spectral signature provided by hyperspectral imaging in each pixel gives information about the type of landscape and its detailed properties, such as soil moisture, the type of soil, water stress in vegetation and biodiversity (figure 1).

The visible and near-infrared reflectance spectra contain absorption, scattering, and fluorescence signatures of functional phytoplankton groups, colored dissolved matter, and particulate matter in the topmost water layers, and of biologically structured habitats.

Most of the challenges in water remote sensing are due to their optical complexity. Aquatic ecosystems can be a mixture of optically shallow and optically deep waters, with gradients of clear to turbid and oligotrophic to hypertrophic productive waters, and varying bottom visibility with and without macrophytes. For example, a lake receives and recycles organic and inorganic substances from within the lake, from its watershed and beyond, such as atmospheric deposition.

As recently recommended by a feasibility study conducted on behalf of the Committee on Earth Observing Satellites (CEOS 2017), observation of the Essential Biodiversity Variables (EBVs) that change rapidly with temperatures, storms, pollution, or physical habitat destruction over scales relevant to human activity (Muller-Karger et al. 2018) requires a new generation of satellite sensors.

The Italian PRISMA and the German ENMaP missions provide hyperspectral data at high spatial resolution, a constellation of small satellites equipped with cosine’s HyperScout® and POLA™ sensors drastically reduce the revisit time and add multi-angular

Figure 1: Alice Mulga, Australia, hyperspectral image acquired by HyperScout®2

Figure 2: Hyperspectral instrument HyperScout manufactured by cosine

Parameter

Swath

Ground sampling distance

Spectral range

Spectral resolution Polarisation

Signal to noise ratio HyperScout 2 280 x 150 km2 POLA

280 x 280 km2

67 m 140 m

50 VNIR spectral bands

3 TIR spectral bands 450 – 950 nm 3 – 6 spectral bands in VNIR spectral range8 – 14 µm

~ 15 nm 20 – 40 nm

~100 >250 (co-addition and/or binning) I, Q, U, V 50 – 100 >250 (co-addition and/or binning) polarisation measurements. HyperScout® and POLA™, are miniaturized hyperspectral and spectropolarimetric imagers that are sufficiently small for nano- and microsatellites.

The onboard data processing system makes it possible to generate geophysical parameters onboard, drastically reducing the amount of data to be downloaded. The instruments combine a very small instrument envelope with a large swath (Table 1).

This combination allows for much more frequent observations, crucial for better understanding the atmosphere-water system and monitoring of marine organisms at short time scales.

References CEOS. 2017. A. G. Dekker and N. Pinnel, editors. Feasibility study for an aquatic ecosystem Earth observing system. Report v. 1.1. Committee on Earth Observation Satellites (CEOS) and Commonwealth Scientific and Industrial Research Organization(CSIRO). CSIRO, Canberra, ACT, Australia.

Muller-Karger FE, Hestir E, Ade C, Turpie K, Roberts D, Siegel D, Miller R et al (2018) Satellite sensor requirements for monitoring essential biodiversity variables of coastal ecosystems. Ecol Appl. https:// doi.org/10.1002/eap.1682

Marco Beijersbergen

Managing Director cosine m.beijersbergen@cosine.nl

Remote Sensing Managing Director cosine m.esposito@cosine.nl

Marco Esposito