Dr. Harry Jol, Dr. Phil Reeder, and Dr. Jack Shroder using GPR at Bethsaida   Ground Penetrating Radar (GPR) is a tool archaeologists will use more and more for excavations in the 21st century. GPR allows archaeologists to survey archaeological sites in a short amount of time with precision and without digging.

GPR works by sending electromagnetic waves from a transmitter antenna through the ground. The electromagnetic waves bounce off buried objects and are collected through a receiver antenna. The signals are then stored in a computer that analyzes the data and can depict the information in a variety of ways. The depth of useable resolution depends on certain factors like the content of minerals in the soil, how much clay and moisture is in the soil, as well as the surface of the ground. The frequency of the antenna is another factor that determines the depth and resolution available. The longer the wavelength the greater the depth but the resolution of the buried objects is not as good as having a shorter wavelength antenna.   Movie: First Overview

City Gates of Bethsaida   GPR was recently used at the ancient city of Bethsaida in Northern Israel. Two thousand years ago, Bethasia was an active fishing community by the sea of Galilee. It is the site where Jesus healed a blind man and walked on water near its shore. Recently, Dr. Harry Jol, professor of geography at the University of Wisconsin - Eau Claire, used Ground Penetrating Radar to map an area by the city gates of Bethsaida.

Excavations at Bethsaida   Movie: Antenna Run Through

The majestic Nahal Hever   Ground Penetrating Radar was used to map possible excavation sites in the Cave of Letters. Located in Nahal Hever, a canyon by the Dead Sea, the Cave of Letters was where many artifacts such as coins, clothes, and letters were found mentioning the jewish leader Bar-Kokhba, who fought against the Romans around the middle of the first century CE.

The Cave is located 200 meters above the canyon bed. Once the data is collected it can be viewed and analyzed in several ways. Programs can synthesize 3D models of the data as well as 2D images.