Why do I need LiDAR?

One of the hotest topics in the industry today is around LiDAR and UAV's of course but that's a topic for another day.  HD-LiDAR is gaining popularity in many applications today and is changing the way mapping is done.

For example, the vertical accuracies are higher than what you can get from comparable Photogrammetry.  You can get a much more accurate and dense terrain model.  You can get an accurate depiction of vegetation canopy and more detail within the hydrography network.  You can pull a cross-section anywhere within the data.  LiDAR can be used to study vegetation.  All of these capabilities/possibilities reduce costs in the overall project downstream.

What are some of the benefits of having high definition LiDAR data?

With a LiDAR scan you are able to model any existing conditions at a level of detail that can not be achieved through any other surveying methods.  Additional benefits include:

• Faster acquisition and processing - unclassified point cloud data within 24-48 hours of flight
• Additional data - obtain highly accurate and precise elevation data for digital terrain modeling of the ground surface, as well as information on buildings, trees, power lines and everything else that the laser hits.  Automated 3D polygons of building structures for example.  Color imagery is also obtained at the same time within the same flight saving time and money.
• Cost - when considering the speed, accuracy and density of the data the overall project costs are significantly reduced.  There are reduced ground based survey requirements also. For example, there is no need to shut down a highway or rail corridor for surveying.

Each project is different and depending on many factors such as location, size of area, terrain and your data  requirements will determine the best technology for your needs.  In regards to LiDAR it could be airborne, mobile and/or terrestrial depending on the application.

To learn more or discuss a current project you have contact us today and we'll be happy to point you in the right direction.

Flood Hazard Mapping

For facility managers who need to stay on top of day-to-day maintenance and even critical situations, combing planimetric mapping with topographic data helps determine the flow direction of a potential hazardous spill and other potential hazards such as flooding.

NOAA is predicting that sea levels are rising twice as fast as projected when most nuclear plants were built.  After the 2011 Fukushima Daiichi Nuclear Power Plant incident in Japan, U.S. nuclear facilities are now required to update their plans to address potential flooding events.

We recently completed a Nuclear Plant project for a firm that was focused on planning and analysis of potential flood hazards.  The analysis required detailed topographic and orthophotography deliverables.  Acquisition needed to be during leaf off conditions, with no clouds and captured within +/- 2.5 hours of low tide.  Using our Trimble 68i LiDAR mapping system, we captured LiDAR & imagery simultaneously. 

Assisting engineering firms and their clients with the geospatial data to assess the safety and analyze severe flooding scenarios and their impact on the community, contact us to learn more. 

Airborne vs. Mobile Mapping LiDAR

Both systems are similar in nature, technological structure and final data, but offer their own unique sets of benefits and constraints. When used together they bring together a combined dataset that yields an unparalleled base for architectural, civil and structural engineering projects.

An airborne LiDAR and digital imaging system, typically mounted in a fixed wing aircraft, but also suitable to rotary wing platforms, is cable of yielding amazing detailed base maps using a combination of photogrammetric data and methodologies merged with amazingly accurate elevation data, typically comparable to traditional field run topographic surveys. Visibility from the aircraft, which can fly over an area as many times is as necessary to produce the density of data that is required, is nearly unimpeded. Voids in data are usually minimal, and limited to areas of impenetrable ground cover, under bridges and other structures, and in some cases, around tall or closely grouped buildings. The density of the LiDAR scan pattern enables penetration of dense vegetation and tree canopy, regardless of the time of year, and yields data to be collected on the ground far in excess of the grid a field surveyor would have to fight to collect, at great expense. Airborne LiDAR also allows mapping of areas that are otherwise in accessible or have severe restrictions on access, such as railroad and highway corridors, industrial areas, marshes, wooded areas or other restricted areas. Effective use of forward, rear and side lap capabilities of the system also allow mapping and collection of features on building walls, embankments and other vertical features. Airborne LiDAR point densities are typically counted in single digit to tens of points per square meter, which is more than sufficient for most purposes, and far in excess of what would be collected by even the most detailed surveyor on the ground.

Mobile mapping also enjoys high accuracy, high scan density and rapid collection of data. While an airborne system can collect multiple passes easily, higher density for topographic feature collection quickly reaches a point of diminishing return. On the other hand, mobile mapping data is already much denser than be collected from an aircraft, but the features it excels at collecting are most often areas of interest that are obscured from the mapping corridor of an airplane, for example tunnels, under bridges and overpasses, building facades, narrow road corridors in urban environments, or cluttered streetscapes with many small points of detail. Mobile mapping point densities are often counted in the hundreds or thousands of points per square meter, obviously yielded stunning levels of detail of its environment. Shortcomings in using mobile mapping for a project are few, but can be notable. The first is directly linked to the detail collected. Dataset sizes can be staggering, necessitating effective management of collection strategies, data storage, editing assets and project workflow. A second less obvious problem is the proximity of the mapping unit to the surface of interest. Data voids can be problematic, as any object in the path of the LiDAR beam essentially stops it transmission, which means substantial data voids which mean multiple passes must be made to collect additional data or terrestrial LiDAR must be employed to fill in the shadows. These areas of shadow include downslopes of embankments, behind sound walls, vehicles, trees, people, structural members and other very common features.

The most effective mapping approach for many projects is a carefully planned combination of the laser scanning technologies. General topographic mapping of wide areas is best left to airborne systems, with detailed corridor and related data gathered from the safety of a vehicle mounted system. Features that need to be located with pinpoint precision, such as structural elements, piping or other critical items can be accomplished through the judicious employment of terrestrial laser scanners, which excel at collecting highly precise and accurate data for use in structural calculations, modeling, deformation monitoring or planning placement of new elements in an existing structure.

If you have a project that has these types of mapping and modeling challenges, you can rely on AXIS GeoSpatial to guide you in the employment of the proper personnel, methodologies and technology to produce the results you need, on time and on budget. We employ all of the technologies discussed, and have an experienced professional staff that draws on years of experience in this ever changing field, and look forward to your measurement challenge.

-Bill Derry, Prof. LS

Director of Surveying Technologies

AXIS Director of Surveying Technologies receives license to practice in Maryland

Easton, Maryland - AXIS Geospatial LLC is pleased to announce that William T. Derry, Prof. LS recently passed his Maryland PLS licensing exam. This adds a third state to his growing list of accreditations as Derry is also licensed in Delaware and Pennsylvania. 

William T. Derry, Prof. LS

Derry has 29 years of experience as a land surveyor, with 15 years as a registrant working in the consulting industry. In support of AXIS’ continued growth, Derry joined AXIS in December 2012 to expand AXIS’ services and technical expertise to include professional land surveying as part of its geospatial data collection and processing. This in-house, licensed expertise provides AXIS additional quality control and quality assurance oversight at key phases along the geospatial processing chain. 

Derry has extensive experience with conventional and robotic surveying instrumentation, GNSS systems including static and real time configurations, control network design and analysis, geometric and geodetic calculations, boundary surveying, title investigation and analysis, structural layout and deformation monitoring, as well as AutoCAD drafting, HD-LiDAR technology and project management. Mr. Derry also maintains an OSHA 40 Hr. HAZWOPER certification, including HAZWOPER Supervisor and Confined Space Entry endorsements. 

“We’re delighted to have Bill as part of our management team and continued growth”, says Justin Lahman President/CEO of AXIS GeoSpatial LLC. “With our HD-LiDAR technology surveying land features to design-scale accuracy and detail, I believe employing a licensed land surveyor to oversee relevant technical areas is a logical, responsible step in AXIS’ growth. Bill is now licensed in three of the many states within which we operate. In addition to PA, DE and MD – we expect Bill to have NC by February 2014 and VA shortly thereafter. Bill plays an integral part in AXIS’ future geospatial data collection and processing services.” 

Founded in 2001, AXIS GeoSpatial LLC is a full service LiDAR, GIS and photogrammetric mapping firm specializing in collecting, processing, updating and providing the core information required in GIS, engineering and surveying applications. AXIS is headquartered in Easton, Maryland with additional locations in CO, DE & NJ. During the past 13 years, AXIS has applied extensive, proven experience in producing high quality aerial imagery, LiDAR and other related geospatial datasets for engineering and government clients throughout the US and abroad. 

For more information please call Erica Insley at 410-822-1441 or visit www.axisgeospatial.com.