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
Sl. No.		Year		Scale	Name of Company		Area
1		1974-75		1:30,000	Capital Air Survey Limited, Canada		All over the country
2		1977		1:5,000	Bangladesh Air Force		Dhaka City
3		1981-82		1:50,000 1:30,000 1:15,000	Capital Ari Survey Limited, Canada		Sundarban & Chattrogram
4		1983-84		1:50,000 1:15,000	IGN France		All over the country
5		1990-91		1:50,000 1:30,000 1:20,000	Finnmap International, Finland		Coastal area, Jamuna & Surrounding
6		1995		1:30,000 1:20,000	Quasco Company, Australia		Chittagong, Cox’s Bazar, Mymensingh
7		1998		1:50,000	Finnmap International, Finland		Coastal Area
8		1999-2001		1:25,000	Kevron Pvt Ltd. Australia		All over the country
9		2003		1:20,000	SOB/JICA/Asia Air Survey		Dhaka City
Sl. No.		Year		Scale	Name of Company		Area
1		2010-11		50 cm GSD	Passco Finnmap International		All over the Country
				25cm GSD	Passco Finnmap International		Chittagong, Khulna, Rajshahi, Barisal & Sylhet City
Chronological history of procured satellite imagery by survey of Bangladesh
1	1998-1995		1:50,000 scale		Spot, France	Sheet Size images of the riverine area
2	2010-11		2.5m GSD		Spot, France	Along the International Boundary of Bangladesh
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

 

• Aerial Triangulation -  03
• Stereo Plotting - 65
• DTM & Orthophoto -  20 

 

and also

• Aerial Triangulation - Inpho Match AT 5.3.1 ( 03 no.)
• Stereo Plotting (65) -  Summit Evolution 6.1 (35 no.) 
  • Summit Evolution 7.2 (25 no.)
  • Summit Evolution 7.6 (5 no.)
  • Auto CAD Map 3D 2011(40 no)
  • Auto CAD Map 2016(23no) and
  • ArcGIS (7 no.)

 

• DTM & Orthophoto  -   Application Master  includes 5.3 & 7.0
  • Match T  DSM , DTM Edit &
  • Ortho Master
  • Ortho Vista includes
  • SEAM Edit  (20 no.)

and LPS software Connected with Server.

 

 

 

PHOTOGRAMMETRIC ACTIVITIES

 

• Aerial Triangulation
• Digitization and Compilation
• Digital Surface Model Creation
• Digital Terrain Model Creation
• Orthophoto Generation
• Contour Generation
• Height Creation all over Bangladesh with respect to Mean Sea Level

 

 

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