Optech CZMIL: Catching the Next Wave (and the Wave’s Data)
Optech Airborne Lidar Bathymetry: A History of Innovation
Advances in airborne lidar technology have been incremental but continuous over the past several years: hardware has progressed in speed and capability, producing instruments that operate at ever faster laser pulse repetition frequencies (PRF) and higher altitudes, covering more area in less time and producing data of greater density with increasing accuracy. Software has moved toward processing greater amounts of raw data more quickly, while real-time data preview functions have become more common. As the industry grows and new applications arise, efforts to streamline the processing workflow grow increasingly important, because the data stream in today’s projects often includes inputs from multiple sensors such as lidar, multispectral scanners and digital cameras.
Dual-wavelength lasers (green for water depth penetration, near-infrared for topography) have been around since 1984, when Optech’s LARSEN 500 first proved that the remote and simultaneous collection of water depth and land elevation data is technically feasible. Optech’s Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) system went on to extend and refine LARSEN 500’s capabilities in a series of models that continued to accelerate laser PRF and expand the operating envelope to enable greater area coverage in less time while yielding higher density data.
This year, the biggest news in the lidar industry comes from recent breakthroughs in airborne bathymetric lidar—laser-ranging instruments that accurately measure water depth from an airborne platform. Optech has released two new bathymetric lidars: the Aquarius and the CZMIL Coastal Zone Mapping and Imaging Lidar. Both of these systems specialize in the simultaneous acquisition of water depth (bathymetry) and land surface elevation (topography) measurement data, but Optech CZMIL advances even further with multiple sensors, innovative data fusion capabilities—and more.
CZMIL and Aquarius: Complementary Solutions
In late 2011, Optech introduced Aquarius, the world’s first compact shallow-water mapping solution. Aquarius is designed to specialize in a narrower range of applications than CZMIL. Since it does not duplicate CZMIL’s multi-sensor and data fusion capabilities, Aquarius offers a smaller, more economical complementary solution. Available either as a simple sensor head addition to the ALTM Gemini or as a complete survey solution on its own, Aquarius presents a new capability to traditional airborne surveyors looking to add further value to their map product deliverables while maintaining their existing ALTM planning and processing workflows.
In 2012 Optech CZMIL pushes lidar bathymetry to unprecedented levels. CZMIL is more than a bathymetric-topographic data acquisition instrument. It’s an innovative airborne coastal zone mapping system that produces simultaneous high-resolution 3D data and imagery of the beach and shallow water seafloor, including coastal topography, benthic classification and water column characterization. Its bathymetric lidar is integrated with a hyperspectral imaging system and digital metric camera. CZMIL’s highly automated workflow includes Optech HydroFusion, a powerful integrated end-to-end software suite that handles all three sensors simultaneously—from mission planning to the production of fused lidar and imagery data sets.
Lidar Innovation: Optech CZMIL
CZMIL’s enlarged aperture receiver (4 times the size of previous sensors) and doubled spatial resolution accelerate data and product delivery, and improve the quality of environmental information products derived from fused lidar and imagery data sets. Until now, coastal areas such as the surf zone and turbid waters have been especially challenging to lidar sensors. But recent advances in processing bathymetric lidar signals—and in the fusion of these signals with peripheral sensor data such as hyperspectral imagery—have led to improved hardware that supports more advanced environmental applications.The design of CZMIL’s integral subsystems endows it with capabilities never before achieved in a bathymetric lidar: along with its three onboard sensors (lidar, hyperspectral and RGB camera), its short laser pulse enables both accurate on-land and water-depth measurements even in the shallow waters of the littoral zone. A circular laser scan pattern allows two “looks” at any target, which makes for optimal target detection. Unlike previous bathymetric-topographic lidar systems that used two discrete lasers (green and near-IR), CZMIL produces high-density data products from a single laser by using a segmented detector capable of up to 70,000 measurements per second. System integration and communication is handled via TCP/IP and a web-based interface to achieve real-time in-field factory diagnostics.
Data: From Acquisition to Fusion
The unique breakthrough of Optech CZMIL is that it opens up a whole new world of possibility with data fusion. By combining data from multiple sensors—lidar (topographic-bathymetric), hyperspectral and RGB orthophotographic—CZMIL outputs data products of a range and variety never before achieved by a single lidar system: water depth measurements, diffuse attenuation, surface reflectance, chlorophyll concentration, colored dissolved organic matter (CDOM), backscattering particles, seafloor spectral reflectance and classification maps are among the most common environmental data products produced from CZMIL-acquired data.The workflow software developed in concert with the hardware, Optech HydroFusion, advances bathymetric-topographic data processing to a whole new level. Optech HydroFusion is a single software package that handles processing from all three sensors and manages all phases of the data workflow—from mission planning to deliverable data products. Built-in lidar point cloud editing tools; an integrated 3D volume visualizer for advanced analysis and editing; multi-sensor data fusion algorithms to produce benthic classification maps; a globe-based GUI for ease of locating, processing and managing data across missions; and the capability to network and share data via an office server across multiple users are among the new software innovations that Optech HydroFusion offers.
Optech HydroFusion’s flight planning module handles the creation of flightlines, establishes data collection attributes for flightlines and allocates flightlines to each survey mission. Data downloading, autoprocessing and visualization modules support the downloading, processing, viewing, cleaning and editing of CZMIL data. Area-based data visualization and editing modules plus an RGB ortho-image mosaic module round out Optech HydroFusion’s range of abilities.
Maxime Elbaz, President of Optech, Inc., describes CZMIL as “the culmination of the transition from lidar instruments to sensor fusion—lidar, camera and hyperspectral sensor—coupled with a highly integrated single workflow from flight planning to the output of fused data sets.” With Optech CZMIL, coastal mapping really is catching the next wave.
Optech is your Survey Solution
Optech is the world leader in the development and manufacture of advanced lidar and camera survey instruments. For over 35 years Optech has refined technology to empower surveyors with fast, accurate and cost-effective solutions.
Optech’s airborne lidar survey products excel in the efficient acquisition of high-accuracy spatial data over land and water. Optech ALTMs offer the greatest flexibility and efficiency available, with a complete line of fully integrated aerial imaging cameras. Whether it’s a high-altitude wide-area mapping project, a low-altitude power line survey, or a small payload, low-power platform requirement, Optech delivers complete data collection solutions for a full range of application and installation scenarios.
Optech’s airborne digital cameras, either standalone or integrated with a lidar, are wide-ranging: large- and medium-format, patented True Forward Motion Compensation, and electro-optical, infrared and multispectral imaging systems. Ruggedized, high-precision metric imaging systems provide camera control, inertial navigation system integration and image processing capabilities, enabling single and multi-sensor solutions that combine visible, multispectral and infrared modules into integrated payloads.
The Optech Lynx Mobile Mapper represents the next generation in the rapid collection of survey-grade 3D data. This revolutionary mobile mapping system integrates the latest innovation in lidar sensors with best-of-class imaging, navigation and product warranty and support.
The Optech ILRIS terrestrial laser scanner is a complete, fully portable, laser-based 3D imaging and digitizing system for the commercial survey, engineering, mining and industrial markets.
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