SPARC operates within the Center for Advanced Spatial Technologies, located in the new (2007) JB Hunt Center for Academic Excellence, of which has more than 11,000 sq feet of labs and offices.
The Center has more than 100 high performance desktop systems and more than 30 larger server systems with upwards of 100 TB of disk space. The entire building has 1 GB home-runs to all desktops and a 10 GB backbone. Commercial and Internet II connectivity are provided.
With funding from an NSF Major Research Instrumentation grant and further NSF support (grants BCS 0321286 and EPS 0918970), CAST has purchased an extensive range of field instruments for remote sensing, survey, photogrammetry, geophysical survey, and related research. Surveying systems include three Leica Viva G15 GNSS and three Trimble 5700/5800 GPS receivers configured for both static and kinematic operation, a Trimble 5600 Robotic Total Station DR200+, Leica C10, Z+F 5006i and Optech ILRIS-3D(mid/long range) scanners and Breuckmann smartSCAN Color HE and Konica-Minolta Vivid 9i close-range 3D scanners, seven Trimble handhelds, 34 Trimble Juno handhelds ProxHs with Zephyr antennas, and a 55 foot lift boom.
Geophysical instruments include a Bartington Grad 601-2 fluxgate magnetic gradiometer system, GSSI SIR-3000 ground-penetrating radar system with 400 and 700 MHz antennae, TRCA earth resistivity and IP meter, a resistivity system with MPX15 multiplexer, and a Geonics EM38-MK2 conductivity/magnetic susceptibility meter.
For further information on the available equipment and software, and workflows and applications applied in archaeology, consult our website at:
Geospatial Modeling & Visualization
The Canon EOS 5D Mark II DSLR Camera has been used for the creation of 3D models using close-range photogrammetry, documentation and Reflective Transformation Imaging (RTI) processes.
The Raytheon Palm IR250 Thermal Imager is a single band hand-held scanner. All natural and manmade objects emit infrared energy; the hotter they are the more infrared energy they emit. Thermal imaging provides the ability to see and record temperature differences. Infrared shares many of the properties of visible light, but its different wavelength has several unique characteristics. For instance, materials that are opaque to visible light may be transparent to infrared and vice versa. Infrared is less subject to scattering and absorption by smoke or dust than visible light and infrared cannot be seen by the human eye. Unlike visible light, which is given off by ordinary objects only at very high temperatures, infrared is emitted by all objects at ordinary temperatures.
The Nikon D200 (originally introduced in 2005) is a digital SLR camera with 10.2 million pixels over a DX format sensor (23.6 x 15.8mm). This particular camera has been modified so that visible light is blocked and infrared light is transmitted. This was done by removing the OEM internal “hot mirror filter” and replacing it with a filter designed to block all wavelengths <720 nanometers. This filter is the equivalent to the Hoya R72 or Kodak Wratten 89b glass lens filters. A custom focus calibration was also done to adjust the auto focus for IR light. This calibration was done specifically for the AF Nikkor 28 mm fixed focus lens.
The IR filter installed is considered to be a 720 nm filter because at 50% transmission, any wavelength below 720 nm is blocked. However, some red light (wavelengths between ~680 and 750nm) is partially transmitted by the IR filter and captured by pixels with a red Bayer filter (25% of the sensor). This means the typical R, G, B channels deliver digital counts equal respectively to Partial Red+IR, IR Only, IR Only.
The Bartington Grad601-2 Magnetic Gradiometer is a vertical component dual sensor fluxgate gradiometer with data logger and two cylindrical sensor assemblies for use in geophysics and archaeology. Each sensor tube contains two fluxgate magnetometers with a one meter vertical separation. As a magnetic gradiometer, this instrument is sensitive to very slight fluctuations in the Earth's magnetic field as a result of objects buried in the shallow subsurface and surface variations. The on-board data logger records measurements collected during a survey and allows for gradient maps of a study area to be prepared.
This instrument is designed for archaeological prospection and allows geophysical surveys to be completed rapidly. The large non-volatile flash memory and fast downloading of data offer improved survey efficiency. The Grad601 has a linear range of 100nT with a resolution of 0.1nT and a range of 1000nT with a resolution of 1nT. A compressed response is provided to 30,000nT. This instrument operates either in survey mode, where data is recorded while covering an area in parallel or zigzag paths, or in a scanning mode where it is used as a search tool with an audible output without data logging.
The Geonics EM38-MK2 is an electromagnetic induction meter, often referred to as a conductivity meter. The instrument measures both magnetic susceptibility and conductivity at two depths (maximum depth is about 1.5 meters) in the ground by inducing an electromagnetic field and then measuring the response of the ground (the secondary electromagnetic field). In this way, electrical conductivity is measured without the use of probes using the electrical component (quadrature) of the secondary electromagnetic field. At the same time, the magnetic susceptibility of the ground is measured from the magnetic component (in phase) of the secondary electromagnetic field. Both of these data types are very useful in archaeology and other near-surface geophysical applications including soil and contamination studies.
The GSSI SIR 3000 is a lightweight ground penetrating radar acquisition system manufactured by Geophysical Survey Systems, Inc. This single-channel portable interface device is designed for use by a single operator and allows for field data to be collected, visualized, and stored for later download. The SIR-3000 is compatible with all GSSI antennas for survey flexibility. Depth prospection varies based on antenna frequency and substrate, but typical investigations range from 0.5 - 3 meters in depth.
With support from the NSF (grants BCS 0321286 and EPS 0918970) the Center has been able to acquire three (3) Leica GS-15 and two (2) CS-15s. The GS-15s are multi-capacity GNSS (global navigation satellite system) capable units that can simultaneously track the US NAVSTAR, Russian GLONASS and European GALEIO satellites. The units are also capable of acquiring the next generation L5 frequency. The CS-15 are comprehensive data loggers and are use to configure the GS-15s.
This instrument is capable of 2" angular precision and, in reflectorless mode can measure distances up to 600m with an accuracy of 3mm +/- 2ppm. With the active prism, the EDM can measure distances up to 5,500 meters with an accuracy of 2mm +/- 2ppm. Used for control point placement, site stake-out, micro-topography surveys and more, the 5600 provides a flexible solution to many geomatics applications. The instrument may be linked via an integrated UHF radio to the powered prism pole so that, as the pole moves from point to point, servo motors swivel the total station's telescope in both horizontal and vertical angles to stay aligned with the active prism. Because the data logger is attached to the prism pole, the operator can control all aspects of the instrument remotely: one person surveys, even high resolution micro-topography, are feasible and have been demonstrated many times by researchers at CAST. Both angle and distance measurements are easily integrated with GPS data collected from the Trimble 5700/5800 in a least-squares network adjustment using Trimble's Geomatics Office software. The systems have been used in a number of innovative projects.
For large-site survey applications requiring extremely accurate horizontal and vertical measurements, the Center operates one Trimble 5800 Receiver/Antenna combination, one Trimble 5700 with a Zephyr antenna, and one 5700 Trimble 5700 with a Zephyr Geodetic antenna. This combination of geodetic grade GPS equipment is configured to operate in static, fast-static, and real-time kinematic (RTK) modes. In static and fast-static modes, all three receivers can be integrated in a classic trilateration network configuration or simply act to measure base-lines between two receivers at a time. In RTK mode, the 5800 and 5700/Zephyr operate as rovers linked with the 5700/Zephyr Geodetic base station.
In addition, all three receiver/antenna combinations can be configured with data modems to communicate with an established NetRS base station operating from the top of the University of Arkansas Science and Engineering Building. The NetRS receiver is owned by DCI Engineering of Little Rock, AR and jointly operated with CAST. Real-time network solutions using the NetRS are available for research activities in and around Northwest Arkansas and archived observations are available via ftp. All of these GPS observations can be easily integrated with traditional EDM and angle measurements from the Trimble 5600 Robotic Total Station in a least-squares adjustment using the Trimble's Geomatics Office.
The Juno ST/SB handheld is a highly productive yet affordable, non-rugged GPS receiver for field data collection and mobile GIS. The Juno ST/SB handheld is Trimble's most compact, lightweight, fully-integrated field computer, providing 2 to 5 meter GPS positioning in real time or after post-processing. CAST currently has 16 of these units available.
Incorporating a high-sensitivity GPS receiver, it has been specifically designed to maximize yield of positions in hostile environments, such as under forest canopy and up against buildings. The integrated WAAS receiver can be used in the field for real-time field corrections of 2 to 5 meters. Or you can collect data in the field and postprocess it back in the office to ensure positions are defined to the required accuracy level for your GIS, and to control the overall quality and consistency of your data.
In July 2010 the Center acquired a Breuckmann smartSCAN HE 5 MegaPixel Color system. This is a fringe projection close-range 3d digitizing system. The system works by projecting a patterned light across the object and uses two cameras to very precisely calculate the locations. Different lenses permit variable sizes of objects and levels of detail to be recorded. The system simultaneously records RGB data. The Center currently has three lens systems M-125 (100-75 mm FOV and 60 mm measuring depth), M-475 (380-285 mm FOV and 235 mm) and an M-825 (660-495 mm FOV and 410 mm measuring depth). Additional lenses up to 1200 mm are available. Example performance specifications of the M-125 configuration are an X, Y resolution of 40 micrometers, resolution limit (z) 2 micrometers with +/- 5 micrometers noise in Z and a feature accuracy of +/- 9 micrometers. As is the case with all scanning, when multiple scans are merged to create a "complete" 3D digital object, the final aggregated output specifications are less than the individual scan specifications. Nonetheless this scanner provides exceptional detail for object work. The system also includes a calibrated rotating table which can be used to quickly acquire scans and merge them. The system also includes a set of calibration panels that allow on-site recalibration of the scanner system.
The Konica-Minolta VIVID 9i is a short range, high resolution color scanning system. This instrument captures micron-level detail of small objects. Though the VIVID 9i has a small field of view, users can scan objects of unlimited size using specialized field techniques. This scanner features an on-board VGA digital camera allowing color textures to be mapped on to the 3D surface data. While it is best suited for use in a laboratory/indoor environment, with minor field modifications it can be used across a variety of on-site locations. An optional calibrated turntable, when used in conjunction with the VIVID 9i, serves to automate the scanning process and expands the utility of the instrument. The use of a professional lighting system is typically required to ensure accurate color capture with this instrument.
The Leica C10 Scan Station scanner is a time-of-flight scanner with an effective operating range of +/- 1-200 m (up to 300 m with 90% reflectivity). Its motorized head allows scanning of a complete 360 degree by 270 degree area. Data is acquired at a rate of 50,000 points/second and can be stored on-board or on a wireless or wired laptop. The C10 has a number of features which make it particularly effective. For example it has automatic target acquisition capabilities that quickly allow survey control points to be integrated to the scan data. The Center has a number of targets for this purpose. It has an on-board video camera which can be used for scan management/planning and is automatically aligned with the scans to texture the point clouds. Published specifications indicate that the accuracy of a single measurement is 6 mm in position and 4 mm in depth (at ranges up to 50 m). The system supports traverse and resection capabilities.
The Intelligent Laser Ranging Imaging System (ILRIS-3D), manufactured by Optech, Inc., is an imaging system that offers direct-to-digital 3D models of any scene. The scanner is about the size of a motorized total station, with on-board digital camera and large-format LCD viewfinder. The ILRIS-3D has a visual interface similar to that of a digital camera. The unit is portable, weighing 12 kg and can easily be used in the field by a single person. As the laser is Type 1, it can be safely used in all settings. With a 20% reflectance surface it has a range of 3m - 1 km. Accuracy in the X,Y and Z dimensions is +\- 10 mm at 100 m. Point cloud data are captured at 2000 points/second. A typical scene with adjacent point spacing can be fully scanned in 10-15 minutes, capturing 1.2 to 1.8 million points.
The Z+F 5006i scanner is one of the Center's three long/mid-range scanners. The Z+F is a phase based system while the Optech and Leica systems are time-of-flight. The Z+F is designed for an effective working range of 1m to ca 50 m - though somewhat longer distances are possible out to its design limit of 79 m. Because it is a phase based system it can acquire data very rapidly - up to some 500,000 points/second and its motorized head permits data to be acquired in a 360 degree (horizontal) by 310 degree (vertical) coverage. As a result it is ideal in scanning building interiors, complex urban spaces and similar situations. Like the CS-15 it can be used in stand-alone mode or with wireless or wired connection to a laptop.
The seven field computers include a Dell M4500 Mobile Workstation, Dell ATG Field Laptop, SIR-3000 GPR Computer, Panasonic Toughbook CF-73 and five Dell Precision Laptops. These computers have been configured to work specifically with field equipment.
The RazorVue Multi-touch Collaborative Interface, a next generation platform for research into human-computer interactions. RazorVue is a 10-foot by 4-foot high, high resolution multi-touch screen that integrates recent work in immersive computer systems along with research on gesture-based interactions.
CAST has a collection of software suited to working with the data produced by individual equipment, and for the merging and integration of data from diverse sources. Software available includes Leica Cyclone, GeoMagic Design X, OptoCAT, Polyworks, LASTools, QCoherent LP360, Aigsoft Photoscan, Erdas Imagine LPS, AutoCAD/Revi, Unity Pro, ArchaeoFusion, Pathfinder and Geomatics Office.
Further information on CAST's software holding can be found on the GMV.
The TerraHawk Aerial Imaging System is built around a DuncanTech multispectral camera and provides CAST researchers with the versatility to conduct refined research in precision agriculture, forestry, rapid response techniques for emergency management, and other areas where near-real-time imagery is critical. Small, compact, enclosed in a case for portability, the TerraHawkTM Aerial Imaging System is an integrated turnkey or complete multi-spectral imaging system for easy-to-use practical application in production agriculture and natural resource management. Features include industrial computer, camera automation, navigation software, GPS integration, and roll, pitch, and yaw camera stabilization.
The Tau-2 Long Wavelength Infrared (LWIR) sensor with a 25μ pixel pitch, 640x512 sensor array is a high-performance, compact, lightweight LWIR uncooled thermal imaging camera suitable for use with the Cinestar 8 Octocopter aerial platform. Both 9mm and 25mm lens are available.
The palm IR thermal imager is a single band thermal imaging system. This device has proved effective in various archeological mapping efforts.
The Nikon D200, altered to operate as an IR sensor, can be mounted on airborne platforms. This device can be used as an effective means of thermal mapping on archaeological sites.
Cinestar 8 Kopter, custom built inhouse for remote aerial survey and imaging. This remote controlled helicopter is perfect for small area surveys using thermal imaging or aerial imaging cameras, as well as other small data collection devices. It can be operated by remote control or programmed to follow a preset flight path autonomously.