This paper presents a field experiment of simple developed antenna system for land vehicle use which was tested by use of the Japanese geostationary test satellite called the Engineering Test Satellite-VIII (ETS-VIII). The antenna system was mounted in a vehicle is compact, light weight, and promising for low cost system. The antenna system was built by a planar array antenna which has a simple tracking capability controlled by a personal computer (PC) as the vehicle's bearing from a navigation system (Global Positioning System (GPS) receiver) is updated in real time. The GPS receiver was constructed to provide accurate information of the vehicle's position and bearing during traveling. The PC was used as the control unit and data acquisition allowing the antenna-beam control as well as the retrieving of the received power levels and error rate. The antenna system was thoroughly examined in the field experiment and satisfactory results were obtained. Steadily received power levels and bit error rate (BER) while tracking the ETS-VIII satellite were confirmed. Yet, the developed system was tested in real environment constraints such as buildings, foliages, utility poles and pedestrian overpasses. The results showed blockage was confirmed. Additionally, the satellite signal was steadily received even it was examined at the inclined-road.