DOI: 10.5061/dryad.zs7h44jpp
title: Data from: Low-frequency radar sounding of ice in East Antarctica and southern Greenland

description: We share data from a decameter-wavelength airborne radar sounder, the Warm
 Ice Sounding Explorer (WISE), that provides ice thickness in areas where
 radar signal penetration at higher frequencies is expected to be limited.
 We share results for three campaigns conducted in Greenland (2008, 2009,
 2010) and two in Antarctica (2009, 2010). Comparisons with
 higher-frequency radar data indicate an accuracy of 55 m for ice-thickness
 measurements in Greenland and 25 m in Antarctica. We also estimate ice
 thickness of the Qassimiut lobe in southwest Greenland, where few
 ice-thickness measurements have been made, demonstrating that WISE
 penetrates in strongly scattering environments.
description: # Data from: Low-frequency radar sounding of ice in East Antarctica and
 southern Greenland Dataset DOI:
 [10.5061/dryad.zs7h44jpp](https://doi.org/10.5061/dryad.zs7h44jpp) ##
 Description of the data and file structure **Low-frequency radar sounding
 of ice in East Antarctica and southern Greenland** Dataset DOI:
 [10.5061/dryad.zs7h44jpp](https://doi.org/10.5061/dryad.zs7h44jpp)
 **Description of the data and file structure** **Description of WISE:**
 JPL and the University of Iowa developed a low-frequency radar sounder,
 named WISE (Warm Ice Sounding Experiment), to probe deep, warm, glacier
 ice. In March 2006, we deployed this radar sounding system in Alaska on a
 single-engine Otter. In March 2007, we deployed the system in Patagonia,
 Chile on a Piper Seneca airplane. In May 2008, we deployed in Greenland
 onboard a Twin Otter aircraft owned by Air Greenland. In October 2008, we
 deployed again in Alaska. In January 2009, we deployed in East Antarctica
 on a Ken Borek (KBA) Twin Otter aircraft. In December 2009, we deployed in
 East Antarctica on a Ken Borek (KBA) Basler aircraft in collaboration with
 the University of Texas, Austin. In 2010, we deployed in Greenland. In
 2012, we deployed in Alaska. In October 2014, we deployed in Patagonia
 from Villa O'Higgins for the last time. The International Polar Year
 project is funded by NASA, Cryosphere Science Program, Dr. Thomas Wagner,
 Program Manager. WISE has been adapted for Cessna, Single/Twin Otter, and
 Basler DC-3. Engineering team included Ali Safaelini (JPL), Yong Gim
 (JPL), Donald Kirchner (University of Iowa). Science Team included Jeremie
 Mouginot (UC Irvine). Principal Investigator is Eric Rignot (JPL/UC
 Irvine). WISE papers have been published in Geophys. Res. Lett. (2013) for
 Alaska, and Annals of Glaciology for Greenland and East Antarctica (2014).
 **WISE data from Patagonia were combined with airborne gravity data to
 provide the first comprehensive mapping of the Patagonia Icefields,
 published by Millan et al. in Geophys. Res. Lett. in 2019**, following an
 initial inversion by Gourlet et al. also published in Geophys. Res. Lett.
 in 2016. **WISE data were included in BedMachine Greenland, Bedmachine
 Antarctica, Bedmap-1, Bedmap-2 and Bedmap-3.**  Dr. Ali Safaeilini, lead
 designer of WISE and brilliant engineer from JPL, originally from Iran,
 died in Spring 2009 abruptly strikened by pancreatic cancer. We
 regretfully did not include Ali Safaenili in our WISE publications because
 at the time it was not accepted by journals to include deceased
 individuals in publications. Ali was the soul of the project and the
 professional reason why Eric kept an appointment with JPL after moving to
 UC Irvine in 2007. Dr. Yong Gim and Kirchner remained active on the
 project. Dr. Jeremie Mouginot produced the entire data set of bed
 elevation but accidentally died in September 2022. The disappearance of
 Ali and Jeremie was a huge dual blow to the WISE team, because of our
 friendships and their key contributions. The WISE project did not extend
 past the hugely successful October 2014 deployment in Patagonia despite
 the great success of the sounder, especially over warm ice (Patagonia,
 Alaska, and South Greenland). The WISE system remains available to
 interested users at JPL c/o Dr.Yong Gim. Dr. Gim has proposals to improve
 the system electronics and performance which required funding at the $100K
 level which was never seeked but remains up to date to this day (November
 2025). The Alaska deep radar sounder developed by Howard Conway, Univ.
 Washington, Seattle, was operated in 2006 together with WISE and benefited
 from key design inputs by D. Kirchner and A. Safaeinili (antenna
 coupling). The system was eventually flown by NASA Operation IceBridge in
 Alaska, c/o Chris Larsen, University of Alaska Fairbanks, PI during
 2009-2019 (See OIB at NSIDC). Data collection suggested, however, that the
 performance of WISE was vastly superior, which was not surprising given
 the hardware configurations of both systems.  WISE comprises a computer,
 transmitter, receiver, matched filter and antennas, power converter, and a
 simple winch system to lower and retrieve the antenna. The transmitter,
 receiver, computer and power supply fits in a 24”x28”x30” ruggerized rack.
 The rack will be tied down on the aircraft deck (rail structure) with
 three straps (breaking strength of 1,500 lbs). The rack will host the
 transmitter, power supply, receiver and computer. The receiver is
 18”x12”x4”. The computer is 8”x20”x8”. The display of the computer is
 16”x13”x4” when folded up. Our equipment includes a mini GPS and a 75-m
 long 8-mm in diameter static rope with the resistively loaded radar
 antenna deployed in flight and removed before landing. The radar operates
 at 2.5 MHz center frequency (120 m wavelength), 1MHz bandwidth via a 1
 microsecond long pulse (CW), 1.5 KHz sampling rate, with a 300 to 800 W
 radiating power. A long chirp (2-5 MHz) is used when the ice is thick or
 radar altitude is high (Center frequency is 3.5 MHz). The power supply
 required for the radar is obtained directly from the power inverter
 onboard the aircraft. WISE does on-board radar processing and real time
 display. Data rate is 1.2 Gbyte per 20 minute operation. The signal to
 noise ratio of WISE was expected to be 50 dB based on the thermal noise
 level, but in practice is in the range of 30-40 dB.  The radar antenna is
 deployed from an existing opening in the back of the plane. The GPS
 receiver (3” in diameter) is stuck on the window inside the cockpit and
 connected to the radar system control. There is no direct electrical
 interface with the aircraft electronics. Radar data is collected on a
 desktop National Instrument computer (NI PXI-8196). First-order analysis
 is performed real time with the onboard processor. All data are brought
 back on disk at JPL for precision processing, scientific analysis and
 publication. The flight lines are drawn on a map and we provide GPS
 coordinates to the pilots. The speed of the aircraft (100-140 knots) is
 not critical because we operate the radar with a high sampling rate (1.5
 KHz). We have 2 sets of antenna 75 m in length mounted on a nylon rope,
 manufactured by University of Iowa. The antenna is deployed in the rear of
 the airplane after take off with the help of a winch and rolled back
 inside the airplane before landing. A plastic rogue (5 cm in diameter) and
 a small weight are attached to the end of the antenna to stabilize its
 drag and angle. Our electronic equipment is lightweight, less than 20 lbs
 of electronics, 15 lbs for the antennas.  **WISE Radar Products**. We
 generated the following sets of L0-L3 Products. Only the L3 products are
 available for general distribution. L0 (JPL): PC time tagged GPS file, PC
 time tagged RAW file, every 20 min, GSP file: 1200 records, RAW file: 1.2
 GB.  L1 (JPL): GPS KML file for Google Earth, Range-compressed file, PNG
 of range-compressed image, C++ based program, semi-automatic.  L2 (JPL):
 Focused file, PNG of focused image, C++ based program, Omega-K focused
 process with altitude corrections.  L3 (UC Irvine): 1D profile map,
 Matlab-based GUI for bed detection.  **Products on this Dryad
 Archive** **are L3 Products:** *
 **WISE_antarctica_V3Nov2011_withgaps.dat:** East longitude in decimal
 degrees, North Latitude in decimal degrees (negative values mean Southern
 Hemisphere), Thickness in meters, No data is -24570.00391 meters.  *
 **WISE_greenland_v3Oct2011_withgaps.dat:** East longitude in decimal
 degrees, North Latitude in decimal degrees (positive values mean Northern
 Hemisphere), Thickness in meters, No data is -24570.00391 meters.  *
 **WISE_antarctica2009dec_v3Nov2011_colors.kmz**: KMZ files readable on
 google listing data takes by date, tone vs chirp, and color coded by
 radar-derived thickness. Black is no data.  *
 **WISE_greenland2010.kmz**: KMZ files readable on google listing data
 takes by date, tone vs chirp, and color coded by radar-derived
 thickness. Black is no data.  * **WISE_greenland2009.kmz**: KMZ files
 readable on google listing data takes by date, tone vs chirp, and color
 coded by radar-derived thickness. Black is no data.  *
 **WISE_greenland2008.kmz**: KMZ files readable on google listing data
 takes by date, tone vs chirp, and color coded by radar-derived thickness.
 Black is no data.  **Files and variables** **Products on this Dryad
 Archive** **are L3 Products:** *
 **WISE_antarctica_V3Nov2011_withgaps.dat:** East longitude in decimal
 degrees, North Latitude in decimal degrees (negative values mean Southern
 Hemisphere), Thickness in meters, No data is -24570.00391 meters.  *
 **WISE_greenland_v3Oct2011_withgaps.dat:** East longitude in decimal
 degrees, North Latitude in decimal degrees (positive values mean Northern
 Hemisphere), Thickness in meters, No data is -24570.00391 meters.  *
 **WISE_antarctica2009dec_v3Nov2011_colors.kmz**: KMZ files readable on
 google listing data takes by date, tone vs chirp, and color coded by
 radar-derived thickness. Black is no data.  *
 **WISE_greenland2010.kmz**: KMZ files readable on google listing data
 takes by date, tone vs chirp, and color coded by radar-derived
 thickness. Black is no data.  * **WISE_greenland2009.kmz**: KMZ files
 readable on google listing data takes by date, tone vs chirp, and color
 coded by radar-derived thickness. Black is no data.  *
 **WISE_greenland2008.kmz**: KMZ files readable on google listing data
 takes by date, tone vs chirp, and color coded by radar-derived thickness.
 Black is no data.  ### Files and variables #### File:
 WISE_greenland2008_v3Nov2011_color.kmz **Description:** See above ####
 File: WISE_antarctica2009dec_v3Nov2011_colors.kmz **Description:** See
 above #### File: WISE_greenland2009_v3Nov2011_color.kmz
 **Description:** See above #### File:
 WISE_greenland2010_v3Nov2011_color.kmz **Description:** See above ####
 File: WISE_greenland_v3Oct2011_withgaps.dat **Description:** See above
 #### File: WISE_antarctica_v3Nov2011_withgaps.dat **Description:** See
 above ## Code/software kmz files can be viewed on many platforms including
 Google Earth, qGIS.  *.dat files are ascii files that are straightforward
 to read. ## Access information **Other publicly accessible locations of
 the data:** Google Drive at UC Irvine. 
 [https://drive.google.com/drive/folders/1kr997wuwE0FnTOgYQyGNl98sShKf6nKv](https://drive.google.com/drive/folders/1kr997wuwE0FnTOgYQyGNl98sShKf6nKv)  **Data was derived from the following sources:** Not applicable.