How WHPacific has applied the LYNX Mobile Mapping System to expand its Survey Business Line.

1. The System
2. Taking a “Surveyors” approach to data collection methods and reliability index factors
3. Best Practice; Site conditions, favorable or not, how we have utilized the LYNX system to maximize our efforts
4. Applications: On-Road; from interstate systems to Rural Tribal roads / Off-Road; mounted on an improvised ATV few places are unreachable / On-The-Water; Riparian studies by Jet Boat
5. Project Library, a series of projects involving bridge detail, site planning, Riparian and Cross-Country data collection
6. Conclusion / Questions

Since the foundations were greatly damaged and shifted towards the southern and eastern slope of the plateau, reassembling for proper interpretation was needed. Laser scanning has shown to be the only method possible for the precise reconstruction of the damaged foundation “puzzle” of the churches. Optech’s ILRIS-3D laser scanner helped in reconstructing this ancient puzzle with its outstanding characteristics and versatility. It helped in proving the geometrical facts of two historical churches and brought the broken pieces of history back together. With an operating range from 3 m to more than 1500 m the ILRIS-3D offers a complete solution for archaeology research combining the closer smaller objects with its geographical wider area. 

Three related projects are being presented and discussed:

• A bridge survey and structural deformation analysis (Axios river bridge in Northern Greece).
• A railway tunnel survey and structural deformation analysis compared to designed geometry (Ag. Stefanos tunnel complex, Athens, Greece).
• Road Interchanges survey and modeling for the evaluation of safety improvement measures (Maintenance Department, Greek Ministry of Public Works)  

Different modules are already in a stage of advanced development, among which many are for LYNX applications:

• laser calibrations modulus for ground mobile system
• photo management tool
• item extraction
• data classification

And for airborne laser scanners:

• waveform laser management tool
• ground extraction
• push boom sensors geocoding tool
• tree extraction
• basic house vectorialization

At this meeting we will describe in detail some of the software solutions that lead us in the development and some specific tasks as LYNX calibration and waveform modules.

 “Virtual scan”, an innovative tool to virtually scan a 3D object by the definition of a new scan position, was tested to merge point clouds from different datasets and to derive uniform grid point clouds, which can be meshed to create surfaces models. Tools for camera calibration and image re-projection are finally used to map colour information according to local camera position or airborne/satellites images.

The 3D-laser scanner used to scan the areas above water level was an Optech ILRIS-ER that allows scanning dynamically from the boat while a SEA SWATHplus-H wide swath sonar system was used to collect underwater topography. A combined GPS and inertial platform (Applanix POS/MV 320) was used to measure position and 3D attitude of the two sensors during the survey. The similarity of the data provided by the two systems (point cloud and intensity value) made it easy to integrate the two surveys using PolyWorks commercial software. The final product was a single 3D model made up of bathymetry and topography.

The trial was carried out with the Italian Navy (Istituto Idrografico della Marina Italiana) in the delightful Porto Venere (Italy) and in particular the area around fortress/church of San Pietro was scanned. This little church sits on the rocky promontory and emanates a sense of serenity that is hard to imagine anywhere else in the world. The church was built by the Genoese between 1256 and 1277 on the ruins of a Paleochristian church that had been built over a pagan temple dedicated to the goddess Venere Ericina (Venus Erycina).

The ILRIS API was used to develop a new controller, able to draw a lot of ROI along a guy. A first coarse scan was done to draw a 2D angular projection of point cloud, coloured with intensity or range. The two anchors and a middle point of guy were pointed to calculate the definition curve of ROIs. Then, after defining a size, an overlap and a spot spacing, ROIs were calculated and sent to scanner.

The resulting point cloud needs to be referenced in a vertical coordinate system. This was done with targets known in XYZ. Polyworks was used for referencing and modelling the mean curve along the guy.

Two methods could be used for determining tension: the first one is direct, and based on search of maximal deflection point. The second is based on least square adjustment of catenary equation. Those two methods need to have an approximation of mass per unit length, as well as a modelling of anchors points. The accuracy of resulting tension is linked to deflection of guy and point cloud quality.

The interface developed over the ILRIS API can also be used to define ROI around target. The needed time for point cloud definition and acquisition on guy or target is divided by 3.

To overcome these shortcomings in the geological field, a software – Coltop3D – was developed for the last for years at the Risk analysis group at the University of Lausanne (Switzerland). Its goal is to ease as much as possible the analysis concerning rock slope relief, structural and morphological analyses. The strengths of Coltop3D are:

1. its data organization and management scheme, as well as its rendering engine, which minimize the required RAM, allows for handling data sets made of 150 millions of point;
2. its specific tools dedicated to structural analysis, notably its color scheme associating a unique color for each combination of local dip angle and dip direction thanks to a lower Lambert-Schmidt stereonet associated with a HSV color wheel;
3. its ability to easily import (and export) unstructured point clouds with various data fields (XYZ coordinates, signal intensity, RGB color information etc.) and processed data, such as regular grids like for digital elevation models;
4.  to select individual points with a wide variety of selection criteria (geometric, geomorphologic, neighborhood relationship, curvature,…).

 These capabilities are demonstrated by structural analyses in various contexts.

IXSEA is a manufacturer of high-grade FOG and Inertial Navigation Systems (INS). This presentation will explain the unique advantages of this double capability for merging the mobile mapping community and the airborne survey industry.
Key advantages include:

• Compact design, as the sensing part and the computing unit can be integrated into a single box
• Access to high-grade performance at a competitive price
• Extreme robustness to GPS drop-outs
• Full compatibility with any type of GPS, including the most recent VRS developments
• Ease of export

Current planetary rover localization techniques are lacking in autonomy and accuracy. An autonomous method of globally localizing a rover is proposed by matching features extracted from a 3D orbital elevation map and rover-based 3D lidar scans from an Optech ILRIS-3DER. The methodology was tested with real data from a Mars-Moon analogue site on Devon Island, Nunavut. The algorithm was able to localize the rover with varying degrees of accuracy. It was concluded that the architecture could be used to accurately and autonomously localize a rover over long-range traverses.