SAGE 2016 GPR

MOST COMMON GPR SURVEY METHOD

IDEALIZED GPR RESPONSE

Noggin Configurations SmartHandle SmartCart SmartTow

Received power is determined by losses due to: RADAR PRINCIPLES Radar system performance (Q) is ratio of transmitted power (Pt) to receiver noise floor power (Pr) expressed in dB, Q = 10 log (Pt/Pr) [dB]. Received power is determined by losses due to: Spherical spreading Exponential attenuation Reflection and/or scattering Losses usually expressed in dB or dB/m

Exponential Attenuation (Absorption) Exponential absorption determined by loss tangent (tan d), tan d = lossy conduction currents/loss-less displacement currents = s/ (2pfe) where s: electrical conductivity f: frequency e: dielectric permittivity. Dielectric constant (K = e/eo), where eo is free space value. For low-loss materials, the attenuation (a) is a = 0.091 (K)1/2 f tan d [dB/m].

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Sample Radar Range Considerations in dB (Annan, 2003)

(Annan, 2003)

POTENTIAL RADAR EXPLORATION DEPTH DEPTH (M)

SAGE 2005

SAGE 2006

GPR 2007 Possible San Marcos Kiva GRID J Average Amplitude Time Slice: 10 to 15 ns Room block 38?

3-D GPR IMAGING Ice

Mars Radar Sounders Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) (1.8 – 5.0 MHz) - 2003 Launch Shallow Subsurface Radar (SHARAD) (15 -25 MHz) 2006 Launch

MARS RADAR SOUNDER RESULTS MARSIS 3.7 km-Deep SHARAD 1 km-Deep < 3.7 km-Deep Reflections from Debris-Layered Glacial Ice

Pictured is deployment of 30 MHz radar system in 1964. Historical Note “Earth” radar sounding (GPR) was developed in Antarctica in the 1940s and into the 60s. Pictured is deployment of 30 MHz radar system in 1964.

1964 Oscilloscope Radar Recording in Antarctica

Antarctic Oscilloscope Radar Recordings Skelton Glacier ~ 1 km-Deep Bottom Echoes South Pole Bottom Echo, 33 ms ~2800 m