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LIDAR with digital imagery is an ideal technology for the rapid and accurate
airborne survey of dam sites, flood areas and transmission line data.
With lidar system, pulses of laser energy are
sent at 50,000 times per second, resulting in a very dense set of information. Typically for transmission line surveys, the
aircraft is flown at 1,000-3,000 feet (300-900 meters) above the ground. With the use of a digital camera system, operating
on standard color (or infrared) wavelengths, additional visual data can be recorded. Using standard color, an aerial record
of condition of the towers, vegetation growth and intrusions into the right of way corridor can be checked. With infrared
wavelengths "hot spots" on insulators
or connectors can be determined. The positioning systems for the lidar ensure that these images have photo center coordinate
values so that areas of interest can be quickly located. The catenary information is used to compute the intersection of spans at the insulators
as well as the sag of the conductors.
Because of the
low flying height and active aspects of the laser system, the unit can be flown in weather when other airborne sensors are
not suitable, and the lidar portion of the system can be flown at night. Color digital imagery, of course, requires daylight
and color can be affected by the atmospheric conditions.
The surveys and mapping for huge hydro-electric
power dams and transmission lines, their environmental impacts and hydrological studies have all been completed over the years
by LIDAR service providers. The construction of dykes, dams and transmission lines requires a precise knowledge of the topography.
Using airborne lidar. Digital terrain models produced using this technology have been used for detailed planning and engineering
during construction projects.
LIDAR technology is
ideal for many forestry applications. Airborne lidar is a methodology of using light detection and ranging systems to produce
detailed maps of the ground more speedily and, in many cases, more economically than almost any other method. Using lidar
results in a digital terrain model of the ground as well as the top (height) of the vegetation. Other features can also be
determined, especially in conjunction with standard or small frame aerial photography (such as access roads, structures and
water courses). The result is these data can be used to help assess stands and timber volume, plan roads, review slope stability,
run-off and other critical data about any area.
Our lidar service provider has been conducting lidar surveys longer than almost all of its competitors. The company uses
the latest generation of commercial lidar which can collect more than 50,000 data points per second to provide very detailed
information.
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