Autonomous phase-sensitive radar (ApRES) measurements at a basal melt channel of the southern Filchner Ice Shelf, Antarctica between 2016/17 and 2017/18

The dataset consists of raw data from six autonomous phase-sensitive radar (ApRES) measurements. The ApRES with two bow-tie antennas were operated at a basal melt channel of the southern Filchner Ice Shelf, Antarctica near the Support Force Glacier. Five short-period ApRES were located at a cross-section of the channel, located east outside the channel (ApRES_oe), at the eastern steepest flank of the surface depression (ApRES_se), within the channel at the lowest surface depression (ApRES_low), at the western steepest flank (ApRES_sw) and west outside the channel (ApRES_we). All four ApRES operated for 9 to 13 days with a measuring interval of 15 minutes. The long-period ApRES (ApRES_oe_long) operated east outside the channel for 361 days with a measuring interval of 2 hours. The short-period ApRES were operated parallel to GPS stations (see doi:10.1594/PANGAEA.932441).
These Lagrangian measurements allow the estimation of basal melt rates based on estimated vertical displacements of englacial and basal reflections. The ApRES is an autonomous operating frequency-modulated continuous wave (FMCW) radar that transmits a tone sweep – called chirp – ranging from 200 to 400 MHz over a period of one second. In order to improve the signal-to-noise ratio, 100 chirps were transmitted within a single measurement. These measurements were repeated every 24 hours. Background of the ApRES-system is published by Brennan et al. (2014) and Nicholls et al. (2015). The processing of the data is described in Stewart (2018), Stewart et al. (2019) and Vankova et al. (2020).