  The Askaryan Radio Array Station 1 (A1), the first among five autonomous
stations deployed for the ARA experiment at the South Pole, is a unique
ultra-high energy neutrino (UHEN) detector based on the Askaryan effect that
uses Antarctic ice as the detector medium. Its 16 radio antennas (distributed
across 4 strings, each with 2 Vertically Polarized (VPol), 2 Horizontally
Polarized (HPol) receivers), and 2 strings of transmitting antennas
(calibration pulsers, CPs), each with 1 VPol and 1 HPol channel, are deployed
at depths less than 100 m within the shallow firn zone of the 2.8 km thick
South Pole (SP) ice. We apply different methods to calibrate its Ice Ray
Sampler second generation (IRS2) chip for timing offset and ADC-to-Voltage
conversion factors using a known continuous wave input signal to the digitizer,
and achieve a precision of sub-nanoseconds. We achieve better calibration for
odd, compared to even samples, and also find that the HPols under-perform
relative to the VPol channels. Our timing calibrated data is subsequently used
to calibrate the ADC-to-Voltage conversion as well as precise antenna
locations, as a precursor to vertex reconstruction. The calibrated data will
then be analyzed for UHEN signals in the final step of data compression. The
ability of A1 to scan the firn region of SP ice sheet will contribute greatly
towards a 5-station analysis and will inform the design of the planned IceCube
Gen-2 radio array.
