Ground penetrating radar system

A ground penetrating radar system comprising

• a first bank of receive antennas arranged along a first axis;
• a first bank of transmit antennas arranged along a second axis approximately parallel to the first axis and horizontally displaced from the first axis;
• a second bank of receive antennas arranged along a third axis approximately parallel to the first axis and horizontally displaced from the first axis;
• a second bank of transmit antennas arranged along a fourth axis approximately parallel to the first axis and horizontally displaced from the first axis;
• a first radar electronics module coupled to the first bank of transmit antennas and the first bank of receive antennas;
• a second radar electronics module coupled to the second bank of transmit antennas and the second bank of receive antennas;
• wherein
• the transmit antennas in the first bank of transmit antennas are interleaved with the receive antennas in the first bank of receive antennas;
• the transmit antennas in the second bank of transmit antennas are interleaved with the receive antennas in the second bank of receive antennas;
• and
• the receive antennas in the first bank of transmit antennas are offset along the first axis from the receive antennas in the second bank of transmit antennas.

A ground penetrating radar system comprising

• a digital module comprising:
• a direct digital synthesizer that generates a digital IF reference signal;
• a digital to analog converter coupled to the direct digital synthesizer that converts the digital IF reference signal to an analog IF transmit signal;
• an analog to digital converter that converts an analog IF receive signal to a digital IF receive signal;
• a digital down converter that digitally mixes the digital IF receive signal with:
• the digital IF reference signal to produce an in-phase product;
• the digital IF reference signal shifted in phase by ninety degrees to produce a quadrature product;
• an RF module coupled to the digital module comprising
• an up-converter that converts the analog IF transmit signal into a transmit signal;
• a down-converter that converts a receive signal into an analog IF receive signal;
• a transmit antenna array coupled to the up-converter for radiating the transmit signal;
• and
• a receive antenna array coupled to the down-converter for receiving the receive signal.

A ground penetrating radar system comprising

• a digital module that generates an analog IF transmit signal and receives an analog IF receive signal;
• an RF module comprising
• a triple-heterodyne up-converter for converting an analog IF transmit signal into a stepped-frequency transmit signal;
• and
• a triple-heterodyne frequency converter for converting a stepped-frequency receive signal into an analog IF receive signal;
• a transmit antenna coupled to the up-converter for radiating the stepped-frequency transmit signal;
• and
• a receive antenna coupled to the down-converter for receiving the stepped-frequency receive signal.

A ground penetrating radar system comprising

• a transmitter;
• a receiver
• an array of transmit antennas;
• an array of receive antennas interleaved with the array of transmit antennas;
• a transmit switch that selectively couples the transmitter to one of the array of transmit antennas;
• a receive switch that selectively couples the receiver to one of the array of receive antennas;
• wherein
• the array of transmit antennas is arranged in one or more rows;
• the array of receive antennas is arranged in one or more rows, each row being approximately parallel to, adjacent to and offset from one of the rows of transmit antennas, so that each receive antenna in a row except one is adjacent to two transmit antennas, and each transmit antenna in a row except one is adjacent to two receive antennas;
• and
• the transmit switch and the receive switch couple the transmitter and receiver, respectively, to a first transmit antenna and a first adjacent receive antenna, and subsequently to the first transmit antenna and a second adjacent receive antenna.

A method for collecting and displaying data from a ground penetrating radar system, the ground penetrating radar system comprising a plurality of transmit antennas and a plurality of receive antennas, each transmit antenna, except one, having two adjacent receive antennas, the system being mounted on a cart that moves over ground, the method comprising

• collecting raw data, comprising
• a. selecting a first of the plurality of transmit antennas for transmitting a signal into the ground, wherein a portion of the signal is reflected back from the ground;
• b. selecting a first receive antenna that is adjacent to the selected transmit antenna;
• c. collecting raw data from the portion of the reflected signal received by the selected receive antenna, the raw data being collected at spatial location (xm, yn), the spatial location (xm, yn) being denoted by {tilde over (Ψ)}mnp where the indices m, n are used to denote position in a grid of spatial locations where the raw data was collected, and p is an index ranging from 1 to P corresponding to a frequency fp at which the raw data was collected;
• d. repeating step c for both receive antennas adjacent to the selected transmit antenna;
• e. repeating steps b, c and d for all transmit antennas;
• f. repeating steps a, b, c, d, and e each time the cart moves to a new location;
• preconditioning the raw data to produce preconditioned data;
• analyzing the preconditioned data;
• and
• displaying images of the analyzed data.