Aerial Mapping

Aerial mapping usually called as Photogrammetry can be used to map large areas efficiently and faster compared to traditional surveying. It captures the horizontal and vertical features of topography of large extent of land. This method uses a series of aerial photographs to create a stereoscopic image of the area. Each aerial photograph taken should include or cover several points which has identifiable XYZ coordinates. Considering these known points, an accurate digital terrain model is developed for the surveyed area. The digital terrain model will provide you the exact horizontal and vertical information using the photos. More specifically, the Aerial photography is mainly used by:(1) Cartographers and planners who obtain detailed information and measurements from aerial photos for turning out maps. (2) Experienced and trained expert interpreters make use of aerial photos to ascertain the land-use patterns and environmental conditions including many things.
There are many advantages of aerial mapping. In essence, it is useful when gathering vast amount of information from larger sites. Its suitable for larger areas with speed and efficiency compared to traditional surveying methods. The possible short comings may exist when it come across thick forest cover or foliage which can obstruct or preventing capturing subject features through aerial photos. There is more possibility that the information obtained is less precise than that obtained using older surveying methods.
The specific advantages of Aerial Mapping or Photography over Ground Based Observation (traditional Surveying) methods:
. Aerial photography offers an improved vantage point or better coverage.
. Aerial photography could stop action.
. It can provide permanent recording.
. Compared to human eye, it has much broader spectral sensitivity
. It has higher spatial resolution and geometric fidelity compared to any ground based sensing technique.

The Surveyor’s Role In Aerial Mapping

The surveyor's role in aerial mapping is vital. He has to provide horizontal and vertical control for the mapping including other related information for the aerial mapping. Usually, the surveyor with the guidance of the aerial mapper, has to position the aerial targets on the ground so that these positions will have adequate visual coverage for the photography. Also, the surveyor has to provide the mapper with necessary coordinates and elevations of all aerial target positions.
These established positions will be used as control points to develop the digital terrain or photographic model for the site. If the aerial photography is covering a highly developed urban setting, the supplemental information provided by the surveyor may include manholes, fire hydrants, or other features which are not visible by photography. In areas where critical matching points are needed, the surveyor has to provide precise information which aerial photos or mapping cannot indicate.
Application of Aerial Mapping or Photogrammetry

The Aerial mapping is used in many useful areas:
• Land-Use Planning and Mapping
• Geologic Mapping
• Archaeology
• Species Habitat Mapping
• Integration of Aerial Photography into Geographic Information System (GIS)

Article Source: http://www.mycontentbuilder.com

Land Surveys Pty Ltd are licensed surveyors and provide a complete array of surveying services in Perth & Karratha, Western Australia.

Please Rate this Article

5 out of 54 out of 53 out of 52 out of 51 out of 5 

Not yet Rated