A collaborative and low cost acquisition chain for collecting spatialized observations in agriculture

• Real-time collection and sharing of manual observations with smartphones. • GNSS RTK enable centimeter accuracy for data geolocation. • Real-time visualization of collected data. • Simplicity and high versatility for diverse agricultural projects. This technical note describes a new data acquisition chain for real-time collection and sharing of georeferenced observations made manually and recorded on a form using a smartphone for agriculture projects. This acquisition chain relies on a low-cost Real-Time Kinematics (RTK) Global Navigation Satellite System (GNSS) rover and the open source Centipede network to obtain corrected geolocation with centimeter accuracy on any Android smartphone device. The Mergin Maps application, which completes this acquisition chain, provides versatility making it possible to design custom projects to meet a large diversity of applications in agriculture (collection of quantitative or qualitative data, images, polygons etc.). The precision provided by these technologies can also be easily combined with existing tools for collaborative data collection. The observations made through this application can be shared in real time with other users involved in the project, even remotely. The simplicity of use of this acquisition chain paves the way for ambitious data acquisition campaigns in agriculture which could involve a large number of participants with different profiles and/or take place over a wide variety of scales (field, domain, cooperative, region, etc.). Two case-studies, which led to the collection of several thousand observations, are presented to demonstrate the potential of this acquisition chain. The first case study deals with mapping missing and dead vines on a 35 ha vineyard, it highlights the flexibility of the acquisition chain and the convenience for sharing data. The second case study highlights the collaborative potential of the acquisition chain with more than thirty participants simultaneously involved in a one day project to make observations of vineyard yields performed at the field level.