approximately 70 cm the receive antenna 15 which is coupled to the receiver subsystem 12 for signal processing is positioned at a receiver height h r above the air ground interface the receiver height h r is approximately 15 cm the antenna foot prints of the transmitter and receive antennae 13 15 are indicated in fig1 by the dotted lines 14 and 16 respectively as is clear from fig1 the foot print 14 of tho transmit antenna 13 is substantially bigger than the foot print 16 of the receive antenna 15 this will result in reception of a signal which is significantly reduced in noise allowing easier processing of the received signal the specific transmit antenna 13 to be preferably used in the present ground penetrating radar system is shown in more detail in fig2 a 2 c fig2 a shows a front view of the transmit antenna 13 while fig2 b shows a side view and fig2 c shows a plan view as can be seen from fig2 a 2 c the transmit antenna 13 is a specifically shaped tem horn antenna the side view in fig2 b shows that the transmit antenna 13 comprises two identical shaped parts 21 22 which are fed by an sma connector 20 the upper and lower part 21 22 are at an angle a with respect to each other which is preferably 20 u00b0 when the length of the upper and lower parts 21 22 is 468 mm the effective length of the horn antenna 13 as measured from the feed connector 20 to the aperture surface 23 is equal to 460 mm the top.