The user requirements for the instrument- and system design, as well as for the in situ data for validation of land and water reflectance were defined by extensive consultation. These requirements were used as the basis for the design concept (Fig. 1) of the instrument, system and network, and subsequently for the development and refinements of the HYPERNETS instrument and system (Fig. 2), and prototype network.
A new hyperspectral radiometer, the HYPSTAR®, has been designed based on an innovative design, combining high performance and moderate cost. Various optical components were tested and a final selection was made based on actual performance with respect to the user requirements. A first batch of 7 radiometers (Fig. 3) was constructed and delivered to partners for testing and performance evaluation. Using feedback from partners to improve the design, a second batch of 7 radiometers and a final batch of 17 radiometers (Fig 4) were constructed and delivered.
The new HYPSTAR® radiometer is embedded within the HYPERNETS host system, which integrates radiometer pointing, data acquisition and data transmission via a rugged PC and includes auxiliary sensors (rain, GPS, etc.) and site-specific power management. A first batch of 7 host systems was constructed and delivered to partners for testing and performance evaluation. Using feedback from partners to improve the design, a second and a third batch of host systems was delivered to partners.
A demonstration video (
https://youtu.be/dfUAPYxg5Cc(s’ouvre dans une nouvelle fenêtre)) has been produced for users showing the HYPSTAR® radiometer and host system.
The HYPERNETS network processor software receives data acquired by instruments in the field and processes to the level of water and surface reflectance with their uncertainties (Fig 5). This software integrates closely land and water processing branches and is now functioning in prototype form for automated daily processing of the data from the validation sites.
The HYPSTAR® radiometer and host system have been tested at 8 water (Fig. 6) and 12 land sites (Fig 7) covering a wide range of biogeophysical and environmental conditions. These validation sites form the core of a network that is appropriate for long-term radiometric validation of all optical imaging satellite missions.
HYPERNETS is now a well-known project throughout the international land and water remote sensing community, including the space agencies and validation entities. The project consortium has been very active in promoting the project by presenting the main objectives of the project at different meetings, conferences and other events. The user need is clear and the community is now waiting for this new instrument to become mature and commercially available.
