Hives Geometric Characterization by Means of Unconventional Geomatic Techniques

The scientific entomological literature defines the status of an active bee hive as “strength”. The strength depends on the number of adult and growing bees as well as on the amount of stored honey and pollen. It heavily conditions the productive and resistance hive characteristics. This is the reason why a continuous monitoring of the hive strength is particularly important. The techniques currently adopted for the evaluation of hive development are based on the visual analysis of the single comb, performed by an operator who is in charge of counting the number of adult bees and quantifying the size of the area of the comb covered by wax, brood (developing bees) and stocks (Graham, 1992). This approach is obviously completely analogical and is strictly related to the skills and experience of the operator; this determines a high degree of subjectivity in the results (Accorti, 1985; Gerig, 1983; Marchetti, 1985). Considering this recognized limit of the traditional procedure, the authors, together with the Di.Va.P.R.A. laboratory of the University of Torino, explored the possibility of approaching the same task in a more scientific and rigorous way. The proposed methodology is mainly aimed at obtaining objective and controlled measurements of the main features of the comb and, possibly, to model it in a three dimensional way. For this purpose, two methodologies were tested and compared: the first one based on a photogrammetric approach performed by a reflex CANON EOS30D camera; the second one based on a ToF (Time of Flight) Swissranger SR-4000 camera that is able to acquire three-dimensional point clouds from a single point of view.