“PLS-CADD modeling of line sag and tree growth is the greatest thing for vegetation management since the chain saw”

The greatest tool ever for accurate detailed information and mapping that can assist in better planning, designing, and depiction of transmission lines and vegetation.

Capture

IMC assists many power companies in mapping transmission lines by capturing Lidar data with a Harrier 56, 200Hz, full-wave form, 16bit intensity system coupled with a 39 mega pixel mapping camera. The Harrier 56 is assembled and designed by TopoSys GMBH. This system is specifically designed for low to medium altitude mapping having high accuracy and density requirements.

The Harrier 56 produces an absolute point accuracy of 19cm horizontal and 7cm vertical without GPS enhancement. With GPS correction applied, coupled with ground-truthing the absolute point accuracy is 5cm to 10cm horizontal and 2cm to 5cm vertically. Control usually consists of GNSS GPS + GLONASS post-processing software TerraPos capable of accurate positioning. The LiDAR have a pulse rate to generate 30- 0 points/m2 in a single swath. The high density scan and a laser point spacing of 0.14m along and across tract ensures exceptional coverage. Color imagery of the subject corridor is captured simultaneously with the LiDAR scan.

The LiDAR scan and Imagery include all substations located along the Transmission Line corridor. Ground Truthing consists of strategically located GPS ground survey points to insure the horizontal/vertical accuracy of the Lidar data set.

Forward Video and Obliques

Digital 39 Mega pixel Vertical Aerial Imagery is captured during the LIDAR mission with a native pixel size of approximately 3cm. This imagery can then be Ortho rectified to the best needed pixel size according to the project specifications.

The oblique Geo-referenced Video is stored directly in digital format and is taken with a broadcast quality video camera. The obliques of the Transmission Structures are taken with a high-resolution digital camera, which has sufficient resolution to read the structures name tag and number.

Video and Obliques are taken and recorded at less than 30 degrees off the horizon.

Deliverables

Feature Coded LIDAR TL: All data is delivered in a .bak (PLSCADD format)

Structure Data:
Location
Ground Elevation at Base of Structure
Structure Height above Ground
Cross arm Height above Ground
Insulator Attach Height

Conductor Data:
Conductor Laser Points
Conductor Attach Points

Transmission Line Conductor Crossings along entire width of Corridor:
Conductor Laser Points
Conductor Attach Points
Overhead Shieldwire Laser Points
First structure on both sides of crossing

Miscellaneous Pole-Lines; Transmission and Non-Transmission:
All poles along entire width of corridor
Wire hits along entire width of corridor
Overhead Shield wire Laser Points
Structure locations on each side of crossing

Weather Station Data:
Wind Speed and Direction
Sun Conditions
Time Interval Data and Date
Location of Weather Stations (Lat/Long)
Start time, Stop time and location of flights