PHOTOGRAMMETRY AND DIGITAL PHOTOGRAMMETRY ACTIVITIES IN SOB
Survey of Bangladesh, the National Mapping Organization (NMO) established in 1767 inherits map making technology from its ancestors. Plane table surveying has been used for data collection from the field for a long time. Invention of aircraft, large format aerial camera and photogrammetric equipment's create a revolutionary change in map making system. Survey of Bangladesh introduced photogrammetry for mapping purposes since 1960.The analogue instruments like A7,A8,B8 were used for aerial triangulation and stereo plotting. Although the process was slow but it gives better accuracy than the traditional plane table surveying. With the advent of modern computer hardware and software photogrammetric mapping system highly benefitted. Without going to analytical system SOB switch on to digital mapping system with a limited number of hardware and SOCET SET photogrammetric software in 1997.
The government of Japan in 2001 helped to enhance the skills of SOB personnel’s in digital photogrammetry mapping technology by imparting technical support through the implementation of 1:5,000 scale digital mapping project at Dhaka metropolitan area. At that time, the scanned aerial photographs were used for stereo plotting.
Gradually SOB realizes that digital photogrammetric system is the key mapping system that can save money, manpower and time, and at the same time can produce accurate map for infrastructural development and help in making plans pertinent to development strategy. Now, the digital maps are key word for infrastructure planning and development and so on in Bangladesh.
So, SOB, with the approval of GOB, is implement a project titled “Improvement of Digital Mapping System of Survey of Bangladesh (IDMS)” to produce 1:25,000 scale digital topographic maps and data covering whole Bangladesh territory using digital aerial photos and satellite images, and 1:5,000 scale digital topographic maps and data targeting 5 major cities using digital aerial photos by digital photogrammetric mapping systems.
For the production of 1;5,000 scale digital topographic maps and data at 5 major cities, Spatial Resolution 25 cm GSD, Radiometric Resolution 8 bit, Spectral Resolution 4 Bands (R,G,B,NIR) , Year of Acquisition 2010-11, Covering Area 5 Divisional Cities, Pixel Size 6 Micron digital aerial images have been taken. Also, for the production of 1;25,000 scale digital topographic maps and data covering whole Bangladesh territory except border, Spatial Resolution 50 cm GSD, Radiometric Resolution 8 bit, Spectral Resolution 4 Bands (R,G,B,NIR), Year of Acquisition 2010-11, Covering Area All over Bangladesh 50 cm GSD digital aerial images have been taken. The digital photogrammetry, especially, aerial triangulation and digital plotting are the most important key work in the digital mapping.
Chronological History of Aerial Photography in Bangladesh |
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Sl. No. |
Year |
Scale |
Name of Company |
Area |
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1 |
1974-75 |
1:30,000 |
Capital Air Survey Limited, Canada |
All over the country |
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2 |
1977 |
1:5,000 |
Bangladesh Air Force |
Dhaka City |
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3 |
1981-82 |
1:50,000 1:30,000 1:15,000 |
Capital Ari Survey Limited, Canada |
Sundarban & Chattrogram |
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4 |
1983-84 |
1:50,000 1:15,000 |
IGN France |
All over the country |
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5 |
1990-91 |
1:50,000 1:30,000 1:20,000 |
Finnmap International, Finland |
Coastal area, Jamuna & Surrounding |
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6 |
1995 |
1:30,000 1:20,000 |
Quasco Company, Australia |
Chittagong, Cox’s Bazar, Mymensingh |
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7 |
1998 |
1:50,000 |
Finnmap International, Finland |
Coastal Area |
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8 |
1999-2001 |
1:25,000 |
Kevron Pvt Ltd. Australia |
All over the country |
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9 |
2003 |
1:20,000 |
SOB/JICA/Asia Air Survey |
Dhaka City |
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Sl. No. |
Year |
Scale |
Name of Company |
Area |
|||
1 |
2010-11 |
50 cm GSD |
Passco Finnmap International |
All over the Country |
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|
|
25cm GSD |
Passco Finnmap International |
Chittagong, Khulna, Rajshahi, Barisal & Sylhet City |
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Chronological history of procured satellite imagery by survey of Bangladesh |
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1 |
1998-1995 |
1:50,000 scale |
Spot, France |
Sheet Size images of the riverine area |
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2 |
2010-11 |
2.5m GSD |
Spot, France |
Along the International Boundary of Bangladesh |
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3 |
2016-17 |
0.5m GSD Stereoscopic |
Digital Globe |
Along the Important rivers of Bangladesh |
Photogrametry
We know since 1960, SOB introduce Photogrammetry for mapping purpose. Digital Photogram metric system in the key mapping system that can save both money, manpower and at the same time can produce accurate map for infrastructural development and can help in making plans pertinent to development strategy. Photogrammetric work station getting data form following source: Aerial images, Satellite images and Terrain Survey. Photogrammetric Workstation Connected with Server
and also
and LPS software Connected with Server.
PHOTOGRAMMETRIC ACTIVITIES
Stereo Plotting
Digital Surface Model (DSM) : 10m interval/20m interval
Digital Terrain Model(DTM) : 10m interval/20m interval
Orthophoto Generation
Contour Generation
Height Creation all over Bangladesh with respect to Mean Sea Level