Dataset DOI: 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

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 

Data was derived from the following sources:

Not applicable.