From crowdsourcing environmental measurements to their integration in the GEOSS portal
Authors: Tsiakos Valantis , Krommyda Maria , Tsertou Athanasia , Amditis Angelos 
Published: March 2020

&lt;p&gt;Environmental monitoring is based on time-series of data collected over long periods of time from expensive and hard to maintain in-situ sensors available only in specific areas. Due to the climate change it is important to monitor extended areas of interest. This need has raised the question of whether such monitoring can be complemented or replaced by Citizen Science.&lt;/p&gt;&lt;p&gt;Crowdsourced measurements from low-cost and easy to use portable sensors and devices can facilitate the collection of the needed information with the support of volunteers, enabling the monitoring of environmental ecosystems and extended areas of interest. In particular, during the last years there has been a rapid increase of citizen-generated knowledge that has been facilitated by the wider use of mobile devices and low-cost portable sensors. To enable their easy integration to existing models and systems as well as their utilisation in the context of new applications, citizen science data should be easily discoverable, re-usable, accessible and available for future use.&lt;/p&gt;&lt;p&gt;The Global Earth Observation System of Systems (GEOSS) offers a single access point to Earth Observation data (GEOSS Portal), connecting users to various environmental monitoring systems around the world while promoting the use of common technical standards to support their utilisation.&amp;#160;&lt;/p&gt;&lt;p&gt;Such a connection was demonstrated in the context of SCENT project. SCENT is a EU project which has implemented an integrated toolbox of smart collaborative and innovating technologies that allows volunteers to collect environmental measurements as part of their everyday activities.&lt;/p&gt;&lt;p&gt;These measurements may include images that include information about the land cover and land use of the area, air temperature and soil moisture measurements from low-cost portable environmental sensors or river measurements, water level and water velocity extracted from multimedia, images and video, through dedicated tools.&lt;/p&gt;&lt;p&gt;The collected measurements are provided to policy makers and scientists to facilitate the decision making regarding needed actions and infrastructure improvements as well as the monitoring of environmental phenomena like floods through the crowdsourced information.&lt;/p&gt;&lt;p&gt;In order to ensure that the provided measurements are of high quality, a dedicated control mechanism has been implemented that uses a custom mechanism, based on spatial and temporal clustering, to identify biased or low quality contributions and remove them from the system.&lt;/p&gt;&lt;p&gt;Finally, recognising the importance of making the collected data available all the validated measurements are modelled, stored and provisioned using the Open Geospatial Consortium (OGC) standards Web Feature Service (WFS) and Web Map Service (WMS) as applicable.&lt;/p&gt;&lt;p&gt;This allows the spatial and temporal discovery of information among the collected measurements, encourages their re-usability and allows their integration to systems and platforms utilizing the same standards. The data collected by the SCENT Campaigns organized at the Kifisos river basin and the Danube Delta can be found at the GEOSS portal under the WFS here https://www.geoportal.org/?f:sources=wfsscentID and under the WMS here https://www.geoportal.org/?f:sources=wmsSCENTID. &amp;#160;&lt;/p&gt;&lt;p&gt;This activity is showcased as part of WeObserve project that has received funding from the European Union&amp;#8217; s Horizon 2020 research and innovation programme under grant agreement No 776740.&lt;/p&gt;