EVALUATING TWO LOW-COST GPS RECEIVERS FOR ACCURACY AND EVENTUAL USE IN PASTURED CATTLE RESEARCH

Using animal-borne global positioning system (GPS) collars, cattle behavioral response to anthropogenic disturbances can be accurately quantified at fine scale. However, the use of dedicated commercial GPS collars in large herd studies is cost-prohibitive. Therefore, low-cost GPS receiver alternatives were evaluated in static placements to determine how their accuracy compares to published data for commercial animal-borne GPS collars. The static accuracies of identical low-cost stand-alone GPS receivers and smartphones were evaluated in an open field without obstructions, under trees with and without canopy, and near an electric fence at 5 min and 1 s sample intervals. The mean circular error probable (CEP) value of the stand-alone GPS receiver was ≤2 m at 5 min and at 1 s in open field placement. The mean CEP value of the stand-alone GPS receiver was ≤3 m at 5 min and at 1 s when placed near the electric fence. The smartphone produced mean CEP values of ≤4 m at 5 min and ≤3 m at 1 s for the fence line and open field placements. Static testing under trees with canopy at the 5 min sample interval produced mean CEP values 100% greater than under trees without canopy at the 1 s sample interval. Low-cost commercial GPS receivers and smartphones with horizontal accuracy of ≤5 m at high sample resolution may offer accurate means of quantifying the behavioral response of cattle to UAVs in large herd studies.