-------------------------------------------------------------------------------- ROSETTA-ICE SHALLOW ICE RADAR (SIR) LINE-BY-LINE PICKS PRODUCT (.MAT/.TXT/.JPG) -------------------------------------------------------------------------------- The ROSETTA-Ice Shallow Ice Radar (SIR) data set contains ice thickness measurements of the Ross Ice Shelf in Antarctica using the IcePod. 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. Ice thickness measurements derived from layer (bright visible horizon) picking. Table 1: IcePod Shallow Ice Radar (SIR) System & INS Receiver Type ------------------------------------------------------------------ The SIR is a Frequency Modulated Continuous Wave (LFMCW) Radar system that is on board the IcePod. It was built and modified at the Lamont-Doherty Earth Observatory. The SIR has a 600 MHz bandwidth with a power output of ~1W and a 2GHz center frequency at a 1ms chirp. 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. RS02 (2016): The second ROSETTA-Ice campaign was flown during November and December of 2016. RS03 (2017): The third ROSETTA-Ice campaign was flown during November and December of 2017. --------------------------- File Format and Information --------------------------- The shallow ice thicknesses are delivered in two formats: (1) Concatenated in Comma Separated Values file format (.csv). (2) Line-By-Line Picks Data Directories that contain directories with additional Pick Data: 'StitchedPicks' in space-delimited ASCII text file format (.txt), 'StitchedPicks' in MATLab file format (.mat), and Picked & Unpicked Radar Frame Images in JPEG file format (.jpg). These data remain undecimated at 50Hz. Surface Elevation is only delivered where a horizon has been picked. As such, the SurfElev variable is not representative of the actual flown SIR surface coverage. ---------------------- File Naming Convention ---------------------- The file naming convention for the thickness picks vary by data product. Examples for Line-By-Line Thickness Picks Directories are below: L650 --> ic_shallow_20180311_0123abcd --> jpg --> RS01_L650_20151123_102343_level1a_SIR_123_NoPicks.jpg --> RS01_L650_20151123_102343_level1a_SIR_123_Picks.jpg --> log --> generateStitchedProds20180311_162055.txt --> mat --> RS01_L650_20151123_102343_level1a_SIR_123-456_StitchedPicks.mat --> txt --> RS01_L650_20151123_102343_level1a_SIR_123-456_StitchedPicks.txt --> ___ --> --> _______ . jpg --> ________ . jpg --> --> __ . txt --> <.MATFileDirectory> --> _______ . mat --> --> _______ . txt Table 3.0: File Naming Convention for Line ASCII and .MAT File -------------------------------------------------------------- Variable: Description: Campaign ROSETTA-Ice Campaign Number Line Number ROSETTA-Ice Line Grid Identification Number YYYYMMDD Date of Survey / Data Collection (Year, Month, Date) hhmmss Time of Survey / Data Collection (hours, minutes, seconds) ProcessingLevel Radar Processing Level Identifier Sensor Type IcePod Sensor Type FileNum File Frame Identification Number. Data is processed in 30km(5minute) frames, each with an identification number. ConcatenatedProductTag Identifier for Concatenated Full Resolution Radar Product Table 3.1: File naming Convention for Line Frame JPG ---------------------------------------------------- Variable: Description: Campaign ROSETTA-Ice Campaign Number Line Number ROSETTA-Ice Line Grid Identification Number YYYYMMDD Date of Survey / Data Collection (Year, Month, Date) hhmmss Time of Survey / Data Collection (hours, minutes, seconds) ProcessingLevel Radar Processing Level Identifier Sensor Type IcePod Sensor Type FileNum File Frame Identification Number. Data is processed in 30km(5minute) frames, each with an identification number. PickedProductTag Identifier for Picked Horizon Visible or Un-Picked in Image File DiffImageTag Identifier for Image with Differenced Filter ---------------------------- Data File Header Information ---------------------------- Table 4: Header Information for Line-By-Line .TXT & .MAT Thickness Picks ------------------------------------------------------------------------ Variable: Description: Lat_line Latitude of echo in degrees Lon_line Longitude of echo in degrees unixTime_line Unix seconds (slow-'along track' time) of each echo Number of seconds that have elapsed since 01 Jan 1970 00:00:00 UTC -leap seconds FlightElev_line Ellipsoid flight elevation in meters. If motion compensation is true, FlightElev is irrelevant SurfElev_line This is ellipsoid elevation of the surface Depth_line Depth of the horizon picked under the surface (thickness) calculated using cIce = 1.68e8 and along track TWTT Bright_line Signal power (dB) of the pixel. This is a relative number with 0 dB being some arbitrary value that is consistent as long as there a no significant changes with processing MotionComp Elevation correction is performed to this altitude (feet). If motion compensation is true, this is the flight elevation. FileNum File Frame Identification Number. Data is processed in 30km(5minute) frames, each with an identification number. ASCII (txt) Directory contains additional Read Me file that is automatically generated with each Stitched Product. --------- File Size --------- Line-By-Line SIR Thickness Picks Directories range from approximately 20 MB to 112 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: 24 May 2019 Document Revision Date: 17 December 2019