ICECAP radargrams in support of the international old ice search at Dome C - 2016

See loc.gov/preservation/digital/formats/fdd/fdd000330.shtml for resources on NetCDF-3, and nsidc.org/data/IR2HI1B/versions/1 for a description of the similar OIB dataset. RADAR Ice penetrating radar provides the geometry of the englacial layers, the bedrock topography, and the basal conditions. SR2HI1B georeferenced radar echo data; 4 Hz NetCDF Data Acquisition Parameters A 1-microsec transmitted chirp was used for both surface and bed.

Two 14-bit digitizer channels with offset receiver gain were used to record returned echoes over 64 μsec, accommodating 120 dB of dynamic range, including accurate representations of power of the surface and bed echoes. Bandwidth: 52.5-67.5 MHz Tx power: 5700 W Waveform: 1 microsec FM chirp generation, analog down-conversion to 10 MHz center Sampling: 12-bit ADC at 50 MHz sampling Record window: 64.74 μsec Acquisition: two gain channels separated by 47 dB Dynamic Range: 120 dB Monostatic Rx/Tx Data rate: 2.2 MB/sec Maximum Doppler frequency: 36 Hz Pulse Repetition Frequency: 6250 Hz Onboard stacking: 32x Processing Approach Where possible focused data (Peters et al., 2007) was included, as this was preferred for englacial reflector tracing.

Where not available, unfocused SAR was substituted. These are converted to magnitude and five of these stacks are incoherently summed resulting in the final 4 Hz sample rate. Error Sources For this Level 1B product, errors in power may be due to transmitter or receiver malfunctions.

Elevated background noise may occur with areas of strong surface scattering (for example crevasses) or Radio Frequency (RF) noise from anthropogenic sources (for example radio calls from the aircraft or other radar systems).