Sharing and cooperation in geo-information technology

Aziz, T. Lukman

Bibliographic data

Monograph

Persistent identifier:: 856479470

Author:: Aziz, T. Lukman

Title:: Sharing and cooperation in geo-information technology

Sub title:: ISPRS Commission VI Symposium, April 15 - 17, 1999, Bandung, Indonesia

Scope:: 1 Online-Ressource (130 Seiten)

Year of publication:: 1999

Place of publication:: London

Publisher of the original:: RICS Books

Identifier (digital):: 856479470

Illustration:: Illustrationen, Diagramme

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Monograph

Collection:: Earth sciences

Chapter

Title:: WG VI/3: INTERNATIONAL COOPERATION AND TECHNOLOGY TRANSFER

Write comment:: Der Aufsatz "Promotion Of The General Understanding And Improvement Of Public Relations, [...] ist im Original nicht enthalten.

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: AUTOMATION IN PHOTOGRAMMETRY. David Collison

Document type:: Monograph

Structure type:: Chapter

67 analog stereo plotters. This was the “foot-in-door” for North American software developers in their eventual takeover of this once European centered industry The latest phase in the evolution of outomation in photogrammetry is concentrated around softcopy systems. Although first introduced commercially in 1991 its only in recent years that significant benefits both technically and commercially have some to the fore in distinguishing these come softcopy systems from the previous generation analytical or optical/mechanical systems. The introduction of WindowNT R based systems with their lower cost Intel based host computers and the familiar graphical user interface (GUI) has been a significant catalyst in the evolution of softcopy systems in recent years. Softcopy has ushered in the dawn of real automation for photogrammetry. Today we are seeing systems capable of • unattended scanning of aerial films • automatic aerotriangulation (autoAT) • automatic generation of DTM’s (autoDTM) • automatic mosaicking. 2. SCANNING Scanning of photographic films has reached a new stage of maturity now those roll-feed scanners are commercially available. The first generation scanners were essentially designed to scan single sheet transparencies, which were manually changed and setup. Roll-feed scanners are capable of unattended scanning, single pass color, auto dodging and interior orientation. See Figure 1. Figure 1. PhotoScan TD with roll-feed system Whilst the scanning of photographs may still be considered a financial impediment to many organizations wanting to embark on softcopy, a service industry has sprouted that provides very economical scanning with per photo costs as low as US$10.00. These service bureaus have helped significantly in stimulating the market for softcopy systems. The industry has progressively adopted TIFF format image files and although there are many forms of TIFF including tiled, unfilled, overviews and JPEG compressed it is now considered a de-facto standard. Most scanners on the market today can generate TIFF format files directly or via conversion. 3. AEROTRIANGULATION By far the most exciting development to date is the process of automatic aerotriangulation. This process forms the basis upon which all-subsequent measurements and made and has been until now very labor intensive, prone to error through artificial point marking and required highly skilled specialists. The following steps are generally incorporated into the AutoAT applications : • Point selection • Point measurement • Point transfer along and across strips • Bundle adjustment The measurement strategy is based on point clusters instead of single tie points, then feature based matching in the first instance followed by least squares refinement. See Figure 2. Figure 2. Automatic aerial triangulation schematic (Image courtesy of Inpho Cmbh) The one step that must still be undertaken manually is the measurement of the ground control points within the project, this will normally involve a relatively few points. And anyhow this step is unavoidable regardless of the methodology chosen. The following table (Table 1) compares the traditional optical/mechanical approach with today’s softcopy AT processes.

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