Harmonize open in-situ data for better re-use
Authors: Boogaard Hendrik , McCallum Ian , Gilliams Sven , Tits Laurent , Janssen Sander , Franziskakis Florian , Jarvis Ian 
Published: February 2023

&lt;p&gt;Open and harmonized in-situ data is crucial for monitoring agricultural resources, addressing food security, and fostering resources sustainability. It will improve capacity to produce relevant, timely, accurate and updated information on agricultural land use and production, especially under changing climates. Such improved capacity will enhance decision making in the agriculture and food security domain. Examples include the need for observed phenological stages to calibrate and validate crop growth models (De Wit et al., 2019; Ceglar et al., 2019) and the use of crop type locations to calibrate and validate crop classification algorithms (Tseng et al., 2021).&lt;/p&gt;
&lt;p&gt;While an abundance of data is being collected by a multitude of users and actors, these data can often not be re-used for several reasons, such as limited access, unclear/proprietary formats, inadequate data standardization, unknown data quality, inconsistent and/or incomplete metadata, unclear (re)use data policies etc. In other words, the (meta)data does not (fully) comply to the FAIR data standards and the GEO Data Sharing and Management principles (Simons et al, 2021).&lt;/p&gt;
&lt;p&gt;While larger initiatives may have resources and facilities to eventually reach FAIR standards, this is challenging for individual researchers and small initiatives. Usually, they lack the right expertise and technical solutions to publish data according to FAIR standards. In such cases the second-best option is that data is published in a way that the data is findable and, if possible, accessible.&lt;/p&gt;
&lt;p&gt;Consequently, there is a need for a community specific solution to further FAIRify (harmonize) in-situ data and make it ready for re-use (see illustration below taken from Top et al., 2022).&amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;
&lt;p&gt;&lt;img src=&quot;&quot; alt=&quot;&quot; /&gt;&lt;/p&gt;
&lt;p&gt;Recently, two initiatives contributed to harmonize open in-situ data. In support of crop type and cropland maps, the ESA funded WorldCereal project built, based on open and free in-situ data sets, a first open and harmonized reference data repository at global extent, ready for model training or product validation. Data of 2017 onwards were collected, harmonized, and annotated. Within the AGROSTAC initiative, supported by the European GEO projects NextGEOSS and E-shape, key agronomy observations such as crop type, phenology, biomass, yield, and leaf area are being collected, curated, and published. For example, data collected via CropObserve, a mobile application developed in E-shape to observe agricultural fields and crops anywhere on earth, are reviewed and published in AGROSTAC.&lt;/p&gt;
&lt;p&gt;Here we show that initiatives like WorldCereal and AGROSTAC deliver harmonized data sourced from many individual data sets. This could save potential users of in-situ data time and money as data sets have been combined and made ready for proper re-use. As these initiatives were developed and funded through finite projects, the community need to find ways to further sustain and strengthen this harmonization task. GEOGLAM, as an international collaboration framework under the Group on Earth Observations is well placed to lead future global efforts related to in situ data coordination, taking advantage of the Essential Agriculture Variables as key drivers for requirements and usability of the data.&lt;/p&gt;