HF antenna prototype for geophysical ground penetrating radar

We describe an HF antenna design and implementation intended for ground penetrating radar applications in glaciology and hydrology. The HF antenna is based on modifications of a twin terminated folded dipole design. Prototypes of the HF antenna were built and then tested with a frequency-modulated continuous-wave radar operating from 25 MHz to 45 MHz, in a preliminary experiment for subsurface water detection.