----------------------------------------------------------------------- ROSETTA-ICE AIRBORNE MAGNETOMETER (MAG) TOTAL-FIELD ANOMALY 20HZ (.CSV) ----------------------------------------------------------------------- The ROSETTA-Ice Airborne Magnetometer (MAG) dataset contains a Total-Field Anomaly collected from an airborne sensor installed on the IcePod. This Total-Field Anomaly has been cleaned, leveled, and decimated to 20Hz. The ROSETTA-Ice project flew three campaigns for three consecutive years during November and December with the IcePod. A total of 43 flights were flown. The data set contains Position, Navigation, & Time (PNT) measurements acquired from a Global Navigation Satellite System (GNSS) Inertial Navigation Systems (INS) system aboard the IcePod. Table 1: IcePod Airborne Magnetometer (MAG) System & INS Receiver Type ---------------------------------------------------------------------- The airborne magnetometer is a combination Scintrex CS-3 Cesium Vapor Magnetometer Billingsley and TFM100G2 Magnetometer. This dual-sensor system samples at a rate of 100Hz, and a resolution of 0.1 nanoTeslas(nT). The PNT system that is on board the IcePod and used for SIR data processing is a NovAtel OEM/SPAN with SPAN LN200 IMU (POD-INS/SPAN). This yields the position of the aircraft to less than 10cm, Pitch, Roll, and Yaw at a sample rate of 10Hz. Table 2: Campaign, Project Year, and Description ------------------------------------------------ Campaign (Year): Description RS01 (2015): The first ROSETTA-Ice campaign was flown during November and December of 2015. A magnetics compensation flight was flown. RS02 (2016): The second ROSETTA-Ice campaign was flown during November and December of 2016. A magnetics compensation flight was not flown. RS03 (2017): The third ROSETTA-Ice campaign was flown during November and December of 2017. A magnetics compensation flight was not flown. --------------------------- File Format and Information --------------------------- The Total-Field Anomaly is delivered in two formats: (1) 20Hz Sample Rate (.csv) (2) 1Hz Sample Rate (.csv) The raw 100Hz data was reduced to 20Hz, and then de-spiked, de-trended, cleaned, and leveled. Airborne magnetics compensation was applied to RS01 magnetics data. RS02 and RS03 were compensated manually to the best of our ability. Where automatic leveling failed, manual leveling was applied to the dataset. Three known issues have arisen in the dataset: (1) RS02 F1007 - A high resolution camera was used in the bubble window of the LC130 above the installed IcePod. This event was document in the IcePod Operator's Log for the flight, and was a visible signature in the magnetics data for the flight. (2) RS03 - F1001 through F1004 the IcePod was installed on LC130 Tail Number 95. After a mechanical problem Tail Number 95 had to be retired, and the IcePod was reinstalled on LC130 Tail Number 94 for the duration of the third ROSETTA-Ice campaign (F1005 through F1012). (3) RS02 & RS03 - Due to time restrictions from weather and mechanical delays, the ROSETTA-Ice Field Team was unable to perform a magnetics compensation flight for the airborne magnetometer data. As such, RS01 is the only segment of the dataset with deliberate magnetics compensation applied to it. RS02 and RS03 were manually compensated by applying careful and calculated thresholds from the Pitch, Roll, and Yaw provided by the PNT information collected by the SPAN-INS. ---------------------- File Naming Convention ---------------------- The Total-Field Anomaly (.csv) was named according to the following file naming convention: ROSETTA-ICE_TotalField_clean-level_20Hz.csv ___ . csv Table 3: File Naming Convention for Concatenated Thickness Picks CSV -------------------------------------------------------------------- Variable: Description: Project-Name ROSETTA-Ice Project Sensor Total-Field yielded from Airborne Magnetometer Sensors ProcessLevelIdentifier Level of processing applied to dataset SampleRate Sample rate of the dataset ---------------------------- Data File Header Information ---------------------------- Table 4: Header Information for Total-Field Anomaly CSV ------------------------------------------------------- Variable: Description: Line ROSETTA-Ice Line Grid Identification Number Flight ROSETTA-Ice Flight Identification Number Season R0SETTA-Ice Campaign Season Identification Number UTCdate UTC Date of Sample Collection (YYYY/MM/DD) UTChms UTC Time of Sample Collection (HH:MM:SS.sss) UTCsod UTC Second of the Day of Sample Collection UNIXTime UNIX Time of Sample Collection Lat Latitude of Sample in Degrees Lon Longitude of Sample in Degrees TFAnom_Unleveled Unleveled Total-Field Anomaly - cleaned, de-trended, and filtered TFAnom_ManualAdjust Segments of Total-Field Anomaly that required manual adjustment for leveling TFAnom_Level Leveled Total-Field Anomaly CROSS_DIFF Cross-Differential Variable, calculated by leveling process CROSS_GRAD Cross-Gradient Variable, calculated by leveling process CROSS_LEVEL Cross-Level Variable, calculated by leveling process --------- File Size --------- The Total-Field Anomaly 20Hz file (.csv) is 2.5 GB. The Total-Field Anomaly 1Hz file (.csv) is 93 MB. ---------------- Spatial Coverage ---------------- The approximate spatial coverage of the ROSETTA-Ice survey is below. Southernmost Latitude: 78° S Northernmost Latitude: 86° S Westernmost Longitude: 150° W Easternmost Longitude: 161° E ----------------- Temporal Coverage ----------------- 09 November 2015 to 04 December 2017 ROSETTA-Ice campaigns were conducted on an annual basis for three consecutive years during November and December with the IcePod. Table 5: IcePod Inertial Explorer Export Profiles and Sampling Rate ------------------------------------------------------------------- IcePod Shallow Ice Radar: 50Hz IcePod Trajectory Standard: 200 Hz -------- Contacts -------- Robin Bell Lamont-Doherty Earth Observatory of Columbia University 108E Oceanography 61 Route 9W - PO Box 1000 Palisades, NY 10964-8000 USA Email: robinb@ldeo.columbia.edu -------------------- Document Information -------------------- Document Creation Date: 7 February 2019 Document Revision Date: 16 November 2020