LiDAR Imagery and its Critical Evaluation for Vegetation Management and Transmission Power...

LiDAR Imagery and its Critical Evaluation for Vegetation Management and Transmission Power Lines

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Ansari R
Pogung Baru, D-34, Yogyakarta, Indonesia
[email protected]

Sarkar H

Abstract:
The impact of electric power transmission line and vegetation has very effective significance for the power transmission lines. Million of people faced electricity loadshading problem due to short circuit between vegetation and transmission power lines. In this study LiDAR imagery were used in solving the above stated problems.

However all the classification was done by macros but due to misclassification of classes manual classification were also done. The maximum difficulties were found for the low vegetation points which get mixed with ground points and these low vegetation points don’t need to be managed as their height were not going to affect transmission lines. The maximum problem was found with the medium vegetation which encounters power lines and needed proper management. The actual height of the power line is 8.5 mu and average height of vegetation in certain places is > 14.00 mu respectively from the ground. Not only that, high Voltage transmission power lines and low voltage transmission power lines need to buffer unto where vegetation will not cross the buffer zone and need to survey on regularly and priority basis.

However, the study reveals that LiDAR surveying provides actual, complete and finest elevation Details and 3D information of power lines and vegetation.

1.Introduction:
The use of laser technology have been developed since the 1960s. Most of people are aware with the use of laser technology in electronic distance measurement devices. LiDAR sensors mounted in airborne platforms began to achieve more consistent and accuracy of data. LiDAR represented Light Detection and Ranging (LiDAR) systems. There are two basic types of LiDAR systems like topography and bathymetry. LiDAR is one of the most recent airborne remote sensing technology and ‘a GPS and an Inertial Measurement Unit (IMU) are the integral parts of the equipment, provide for continuous monitoring of the position of the aircraft and its attitude’ (Réjean and Pierre, 2006).

In this study LiDAR data are used for the vegetation management and Transmission Power lines where long trees are crossed transmission power lines and create load shading problem for the million of people and such of problem affects daily life and faces havey losses. To maintain such kind of problem new researches come into existence.

Remote sensing depending upon its resolution according to Susanto (2004) remote sensing resolution have four types: Spatial, spectral, temporal and radiometric where as airborne remote sensing used point resolution which measure the distance of an object. However time changes, technique of data collection and accuracy also improved. LiDAR makes direct physical measurements and provide high accuracy data (Réjean and Pierre, 2006). In a word LiDAR a better understanding technology have greatly revolutionized in Remote Sensing Era and the usefulness of LiDAR as a valuable mapping tool and have a Potential applications.

3.Problem formulation:
The impact of electric transmission line and vegetation have significant role for power transmission. Million of people faced electricity load shading problem due to short circuit between vegetation and transmission power lines.

4.Benefit of this Research:
This research will beneficiary for the area where dense vegetation and thousands of hundred kilometer long transmission power line passes and manage the power load shading problem. It also help to proper management of Vegetation basically in highly dense tropical vegetation. This is a scientific approach, less time consuming as well as for human well being.

5.Research of Objectives:
The main objectives of this research are

  1. 3D mapping of vegetation and power transmission lines.
  2. Find out the electricity power supply problem and its proper management.


Fig: Follow Chart of the Research Method.

8. Analysis and Its Evaluation:
As LiDAR captured the point data and points directly measures the object’s distance. So it is very useful to classify the 3D objects. In the following figure1 cross section of low vegetation and ground points were well classified and TIN model were generated from ground point which shows 3D surface. Even there are some difficulties for the interpretation because with some extent it is difficult to identify that which point refers which classes because vegetation point height is lying same with ground point height.


Fig:1 Front View of the Ground Class and Vegetation Class with TIN model of Ground.

In this study more then ten classes were taken into consideration for detail studies and each class were clearly defined. However in the class divination, MACROS were used but manual checking was done for maximum accuracy purposes. The figure 2 clearly represent that each classes were well defined but there are few classes which get mixed with another classes. Though it is quite difficult job to identify the class with out priori of knowledge.


Fig:2 Front View of different Classes.

However our main task in this study is to identify the vegetation classes which overtake the transmission power lines and find the solution for proper management of vegetation detail study shows that the medium vegetation classes are the most affected trees which crosses transmission power lines. The medium vegetation were measured averagely 14mu where as the transmission power lines height 8.5mu. from the ground. It is assumed that in such a condition it will create short circuit for certain areas where vegetation crosses the transmission power lines.


Fig:3 Vegetation Overtake the Transmission Power Lines.

Here medium vegetation taken into consideration for management purposes. It is quite difficult to measure the frequency of electricity and upto which level it will affects vegetation so cut down the vegetation canopy top at certain level which will not affects the low voltage power transmission line not only that need to proper survey on regular priority basis.


Fig:3 Vegetation and assumed buffer zone .

Conclusion:
LiDAR surveying provides actual, complete and precision elevation data. LiDAR data is more enough to identify vegetation class which encounter transmission power line and as a result short circuit and load shading problem and could be managed through proper managerial task. It is hoped in near future LiDAR technology will replace the photogrammetry.