Airborne Lidar

Expertise in airborne lidar is a core capability of OTH Geomatics. Our lidar systems have been specifically selected for maximum performance, utility and reliability under some of the most challenging operating and environmental conditions possible. Vertical Accuracy is on the order of 1-3 cm (RMSEz); Horizontal Accuracy: 10-15 cm; GSDs anywhere from <5 to >200 points/m2

All lidar data acquisition provides discrete return (first, second, third and last pulse returns), along with a 12-bit intensity returns. Optional acquisition streams include 12-bit full waveform data serving as inputs to collateral processing. Airborne lidar services can be broadly broken down into three broad categories, satisfying most wide area and corridor topo requirements:

Standard Lidar

Density: 1 - 0.25 pts /m²
Nominal Pulse Spacing: 1 - 2m
DEM Post Spacing: 3m (1/9 arc-sec)
Vertical Accuracy (RMSEz): 18.5 cm
Equivalent Contour Accuracy: 2 foot
USGS Draft-13 compliant; Meets FEMA specs for standard contours

High-Accuracy Lidar

Density: 2 pts /m²
Nominal Pulse Spacing: 0.7 m
DEM Post Spacing: 1m (1/27 arc-sec)
Vertical Accuracy (RMSEz): 9.25 cm
Equivalent Contour Accuracy: 1 foot
Meets FEMA specs for supplemental contours

High-Accuracy / High Density Lidar

Rotor wing deployment provides higher density data to suit specific inspection requirements.

Density: 8 pts /m²
Nominal Pulse Spacing: 0.35 m
DEM Post Spacing: 1m (1/27 arc-sec)
Vertical Accuracy (RMSEz): 9.25 cm
Equivalent Contour Accuracy: 1 foot
Meets FEMA specs for supplemental contours

 

Standard Flight Profiles

We have developed specific payload configurations and flight profiles to address a wide variety of airborne remote-sensing requirements. Among them:

High Altitude Wide-Area

<6000AGL<13000

Wide-area mapping work is typically covered with conventional fixed-wing deployment with extended flight lines and an constant AGL. This will produce 3-5m lidar DEMs and/or 2-ft orthoimagery. Special provision is taken on longer flight lines to compensate for IMU drift. This is a 'fair-weather' operation, flown when cloud cover meets requirements.

Mid Altitude Area

<2500AGL<6000

Engineering Utility work is either flown on fixed-wing or helicopter platforms depending on project specifics and logistics. This is suited where requirements call for 1.5m lidar DEMs and/or 1-ft orthoimagery.

Low Altitude Area/Corridor

<1000AGL<2500

Most corridor survey work can be flown under this regimen. It provides for a good balance of density and coverage vs time. This is suited where requirements call for either 0.7m lidar DEMs and/or 6-inch orthoimagery using medium-format equipment. It generally provides effective single-pass coverage for riparian and coastal zone projects.

"Below-Deck" Inspection Corridor

<1000-ft AGL

Corridor inspection is deployed on a Category-A rotor wing, allowing safe terrain-following flight regimens below 1000'. Combined with shapefile tracking capability, ground speeds down to zero and lidar PRFs >300kHz, this provides the highest possible ground sampling resolution from an airborne platform.

This is ideally suited for power line corridor work or detailed road or river surveys. In-flight shapefile tracking and the ability to execute flat turns during flight ensures complete single-pass coverage with ground swaths as little as 100-ft wide. This also provides VFR operation in conditions which other aircraft are restricted, including low-ceilings and urban over-flight.

This yields high-resolution data that typically satisfy the processing and analysis requirements for utility corridor analysis, or any other application where dense mass-points coverage provides increased analysis capability.

Mid Altitude Area

<13000-ft AGL

Engineering configurations are available for pressurized aircraft operation above 13,000-ft or 4,000m AGL. Contact our Applications Specialists with your requirements.