DOI: 10.5285/e718a95d-76f0-46bf-ad93-ef02b0ba1f9f
title: Kinematically corrected GNSS/INS buoy data during the MOSAiC expedition 2019-2020

description: This dataset contains the post-processed GNSS/INS buoy data for a kinematic correction of a moving base station. The GNSS/INS buoys were deployed on sea ice during the 2019-20 MOSAiC expedition. These buoys recorded raw GNSS/INS data at a sampling rate of 10 Hz. For the kinematic correction, two buoys (with overlapping measurements of each other) were selected, and one of the buoys was used as a moving "base" and the other as the "rover". The post-processed dataset contains kinematically corrected latitude, longitude and velocity of the rover, as well as the baseline distance between the rover and base. The main objective of the kinematic correction is to create high-precision and high-frequency data to measure ice dynamics at a few centimetre accuracies. The buoys were assembled by the University of Huddersfield team and the deployment was done by the MOSAiC ice team throughout the expedition. This work was funded by NERC MOSAiC program NE/S002545/1.
description: GNSS/INS buoy system was assembled by the University of Huddersfield. Each buoy system consists of a miniature inertial system (Spatial), a data storage (ILU), a GNSS antenna and a power supply. These sensor components were supplied from Advanced Navigation (advancednavigation.com) and Innovelec (innovelec.co.uk) (see Instrumentation for detailed information on the sensors), and were then assembled in a weather-proof plastic case for deployment. A total of six sets of the GNSS/INS buoys were shipped to the expedition, but the number of the buoys deployed on the ice varied throughout the expedition due to the logistical and environmental circumstances. The deployment of the buoys was made in the vicinity (within 2 km) of RV Polarstern at the MOSAiC drifting site. Kinematic correction requires the base station measurement should overlap the period of the rover measurement, so the availability of the kinematically corrected data is affected by environmental and operational limitations (see Temporal coverage for the data availability). This data set provides high-precision (centimetre accuracy) and high-frequency (10 Hz) ice dynamic data to study ice drift, lead/ crack opening/ closing and ridging of sea ice with the precision of a few centimetre scales.
description: Each GNSS sensor unit consists of Spatial, Data Interface Logging Unit (ILU), and antenna. Spatial is a rugged miniature GPS aided inertial navigation system and AHRS that provides accurate position, velocity, acceleration and orientation. It combines temperature calibrated accelerometers, gyroscopes, magnetometers and a pressure sensor with advanced GNSS receiver to deliver accurate and reliable navigation and orientation (see advancednavigation.com/solutions/spatial/). The position accuracy can be a few centimetres as long as the antenna has a good sky view without any obstructions. Data Interface Logging Unit (ILU) is a device server that interfaces to Spatial and provides data logging, a web interface, a time synchronisation server and different data input/output option. Two types of GNSS antennas were used: Antcom (G5ANT-53A4T1) and Tallysman (TW3972).
description: The kinematic correction of the raw GNSS/INS data was conducted using Kinematica from Advanced Navigation (advancednavigation.com). The raw GNSS/INS data (in ANPP format) was converted to RINEX format for a kinematic correction with a moving base station. The processed data contain Moving Base Fix Type (i.e., the type of GNSS fix between the rover and the base station). For the data quality, the data with Fix Type* = 7 (i.e., RTK fixed - Carrier phase ambiguities have been resolved) were selected in this dataset. Note that Leg5 data are not included in this dataset. No changes were observed in Leg5 and some errors were found during the data processing. *Fix Type: Fix type 0 - No Fix; 1 - 2D; 2 - 3D fix (no base station data); 3 - SBAS; 4 - Differential (Base station data does not include carrier phase corrections); 5 - Omnistar; 6 - RTK Float (Carrier phase ambiguities cannot be resolved); 7 - RTK Fixed (Carrier phase ambiguities have been resolved).