International cooperation and technology transfer

Fras, Mojca Kosmatin

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Monograph

Persistent identifier:: 856490555

Author:: Fras, Mojca Kosmatin

Title:: International cooperation and technology transfer

Sub title:: Ljubljana, Slovenia, February 2 - 5, 2000 : proceedings of the workshop

Scope:: VI, 163 Seiten

Year of publication:: 2000

Place of publication:: London

Publisher of the original:: RICS Books

Identifier (digital):: 856490555

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:: Digital Photogrammetric cameras: a new forward looking approach. P. Fricker, R. Sandau, P. Schreiber

Document type:: Monograph

Structure type:: Chapter

sensors have their advantages and the most likely scenario for the future will be an increased emphasis on data fusion as users select the sensors most likely to provide their information in each case and rely on their workstation software to use all the data together. The two types of data will be complementary rather than competitive. 2. AIRBORNE DIGITAL SENSORS: REQUIREMENTS To have any chance of an impact in a market place spoilt for decades by high performance film cameras, an airborne digital sensor must provide: • large field of view and swath width • high resolution and accuracy, both geometric and radiometric • linear sensor characteristics • multispectral imagery • stereo. The first requirement, however, seems to rule out area CCD arrays, because readily available models in mid 1999 are 4Kx4K pixels or less, whereas a linear array of 12,000 pixels is readily available, requiring only one third as many flight lines. Considerable research work has been done in Germany since the 1970s, which has demonstrated the suitability of three panchromatic lines on the focal plane, with additional multispectral lines near the nadir. This obviates the need for multiple area arrays to provide a wide field of view and a multispectral capability (Figure 1). The left-hand diagram suggest how the focal plane could be populated using the three line principle: three panchromatic lines give the geometry and stereo, whilst additional lines, their sensitivity controlled by filters, give the multispectral information. In the right hand diagram, multiple area array CCDs and lenses are required to provide both the same ground pixel size and multispectral range as the three-line approach. multiple RGB + infrared arrays to increase FOV WÊÊMÊMÊÊÊÊÊËËtÊËÊËÈÊÊÊÎ&&iËÊtmËÊÊÊmmÊ0ÊMmm Fig. /. The alternatives: linear and area CCD arrays. 3. THREE-LINE SCANNER APPROACH The three-line concept results in views forward from the aircraft, vertically down and looking backward (Figure 2). The imagery from each scan line is assembled into strips (Figure 3). The characteristics of relief displacement in the line perspective geometry of the strip approach vis a vis the conventional central perspective geometry are indicated in Figure 4, showing the line perspective geometry of the three-line imagery on the left and the familiar central perspective geometry of the film photograph on the right. The angles between the incoming information to the three lines are, of course, fixed. With three lines there are three possible pairings for stereoscopic analysis - strips 1 and 2, 2 and 3, and 1 and 3. With film cameras, the parallactic angle is a function of principal distance and airbase. Moreover, every object appears on all three strips, whereas on film imagery only 60% of the area of any one photograph is in a triple overlap.

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