[Project: GAMBIT / IceBridge]
Gravity measurements are made using a Sander Geophysics Airborne Inertially Referenced Gravimeter – AIRGrav. This system is the only purpose-built airborne gravimeter, and was designed specifically for the unique characteristics of the airborne environment. This design approach has resulted in a superior gravity instrument which can be flown in an efficient survey aircraft during normal daytime conditions. In addition, AIRGrav can easily be flown in combination with magnetic and/or radiometric instruments to increase the survey benefits.
S. Sander, M. Argyle, S. Elieff, S. Ferguson, V. Lavoie, L. Sander. Technical specifications of the AIRGrav Airborine Gravity System . [ PDF ]
M. Studinger, R.E. Bell, N. Frearson. 2008. Comparison of AIRGrav and GT-1A airborne gravimeters for research applications , Geophysics, Vol. 73, I51, doi:10.1190/1.2969664. [ PDF ]
Laser Altimeter (LiDAR - Light Detection and Ranging)
[Project: GAMBIT / icePOD]
The RIEGL LMS-Q240i makes use of the pulsed time-of-flight range measurement principle and beam scanning by means of an opto-mechanical scan mechanism, providing fully linear, unidirectional and parallel scan lines. The instrument is extremely rugged, therefore ideally suited for the installation on board of an aircraft, and also compact and lightweight enough to be used under limited space conditions (e.g. in small single-engine planes, helicopters or other vehicles). The instrument needs only one power supply and provides discrete line scan data, directly stored on a computer system, via the integrated LAN-TCP/IP interface. The binary data stream can easily be decoded by the user’s software using the available software library. The LMS-Q240i offers a unique combination of wide scanning angle, high maximum range, high measurement accuracy, narrow laser beam; all within a compact and robust housing.
- Maximum range 650 m @ 80 % target
- Ranging accuracy 20 mm
- Data rate 10 000 meas. / sec
- Scanning rates up to 80 scans / sec
- Scanning ranges up to 80°
- Perfectly linear scan
- Rugged IP64 housing
- Integrated TCP/IP Ethernet interface
- Input for GPS time synchronization
- RIEGL Laser Measurement Systems. LMS-Q240i – Technical Specifications . [ PDF ]
[Project: GAMBIT / IceBridge]
The CS-3 High Resolution Cesium Magnetometer offers the highest sensitivity and lowest noise on the market, with automatic hemisphere switching and a wide voltage range. In addition to having the maximum active zone and minimum dead zones, it also maintains the smallest heading errors.
- CS-3 sensor offers unsurpassed performance as an industry standard.
- It is the choice of airborne magnetometer system operators.
- The CS-3 will provide indisputably the best in your magnetic data quality.
- Scintrex CS-3 Technical Specifications [ PDF ]
Deep Ice Radar (DEEP) | [Project: icePOD]
Deep Ice Radar (or Ice-Penetrating Radar) pulses a radio or microwave frequecy signal that penetrates the ice surface to the bed below. In the crevassed ice of an outlet glacier DEEP can image ice thickness through 1-2 km ice, and in the interior of the ice sheets it can move through 3-4 km of ice to resolve the reflectivity of the bed, allowing us to constrain whether there is water at the bed. The sensitivity for ice thickness measurements is 10 meters or better. The radar will have a center frequency of 150 MHz and a bandwidth of up to 40 MHz.
This single, low frequency beam radar will be used for ice sheet thickness, basic bed mapping, basal refectivity to show the distribution of basal water, internal layers to show ice dynamics, and accretion ice on the bottom of the ice layer to show basal hydrology. The radar will need to be located outside the pod without adding to the drag on the plane or causing additional testing of the instrument package.
Shallow Ice Radar (SIR) (100-200m) | [Project: icePOD]
Shallow Ice Radar allows area wide spatial mapping of the annual accumulation layers in the icesheet. The radar will be used to image the firm ice with 1-2 m resolution, in order to map the variability of accumulation in regions of interest and to accurately convert surface change to overall mass change.
The SIR is a small downward looking airborne radar working in the L-band. It is designed to provide high-resolution images of near-surface features within ice up to 100m thick. This makes it ideal for looking at the internal structure and ice-water interface at the edges of continental ice shelves, multi-year sea-ice and annual sea-ice with a resolution on the wavelength scale of around 30cm. Operated in tandem with differentially corrected GPS data it will provide geo-referenced sounding imagery of the ice that is being overflown. The head unit will fit into one of the two radar bays available in the pod and will interface with the power and data connections found there. Data will be recorded to solid-state hard drives on the Master Control Unit located in the Instrument rack inside the aircraft, positioned for easy access by the operator. The system will be run autonomously once data collection has been initiated by the Operator and the Transmitter has been switched on over the target area.
Radar Depth Sounder | [Project: GAMBIT]
GAMBIT utilized a suite of sensors developed at the NSF-funded Center for the Remote Sensing of Ice Sheets at the University of Kansas. This suite included a 150-MHz radar with multiple receivers that provided digital beamforming capability by recording data from each element of the receive-antenna array. The digital beam forming capability allows us to image the ice bed over a swath of about 1 km on both sides of the aircraft, and measure ice thickness and map deep internal layers along the aircraft path simultaneously. Another sensor is an ultrawideband radar that operates over the frequency range from 500-2000 MHz, mapping internal layers in the ice to a depth of about 150 m at a resolution of about 0.1 m. From an airborne platform with the accumulation radar operating from 600 to 900 MHz, PGG mapped near-surface internal layers to a depth of about 150 m with resolution of about 0.6 m.
Shared Computational Resources
- Four Octa Core AMD Opteron 6136 Processors (2.40 GHz, 12M L3, 6.4GT/s)
- 128GB PC3 SDRAM 1333MHz
- Two 80 TB Raid 5 Storage Systems
- CentOS Linux 6.0
- Matlab R2011b 64-bit
- R 2.14 64-bit
- One Quad Core Xeon E3-1245 Processor (3.30 GHz, 8M L3, 2GT, Turbo)
- 16GB DDR3 SDRAM 1333MHz
- Windows 7 64-bit
- ArcGIS Desktop 10
- ArcGIS Server 10
- Matlab R2011b 64-bit
- Geosoft Oasis Montaj 7.3
- R 2.15 64-bit