Ground penetrating radar for asparagus detection

Ground penetrating radar is a promising technique for detection of buried objects. Recently, radar has more and more been identified to provide benefits for a plurality of applications, where it can increase efficiency of operation. One of these fields is the industrial automatic harvesting process of asparagus, which is performed so far by cutting the soil ridge at a certain height including all the asparagus spears and subsequently sieving the latter out of the soil. However, the height where the soil is cut is a critical parameter, since a wrong value leads to either damage of the roots of the asparagus plants or to a reduced crop yield as a consequence of too much biomass remaining in the soil. In this paper we present a new approach which utilizes ground penetrating radar for non-invasive sensing in order to obtain information on the optimal height for cutting the soil. Hence, asparagus spears of maximal length can be obtained, while keeping the roots at the same time undamaged. We describe our radar system as well as the subsequent digital signal processing steps utilized for extracting the information required from the recorded radar data, which then can be fed into some harvesting unit for setting up the optimal cutting height. (C) 2016 Elsevier B.V. All rights reserved.