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coordinates and the parameters from the "control files" to reconstruct the
models without repeating the external orientation.
The part of the subsystem concerned with the compilation of information on
features that is based on stereocompilers, allows for the use of simple and
fast compilation techniques after a minimal preparatory work on the
orientation of the stereo-orthophotos (i.e. shifting and rotation of
stereomate in its own plane). The digitized information is fed from the
subsystem into the external storage devices of the land information system
via the editing facility enhanced by the editing techniques inherent in the
design of stereocompilers. This compilation subsystem allows for a more
complete exploitation of the collected information in the land system's data
base by supporting the generation of various output forms with combined
pictorial and graphical presentation of information such as orthophoto maps
with various line-drawn overlays. Also, the field work related to the
establishment of a data base comprising field checking, interpretation and
collection of semantic information that is not contained in the original
photographic records, can be conveniently based on orthophoto mosaics and on
stereo-orthophoto prints instead of the original aerial photographs. In
general, it can be stated that a photogrammetric information compilation
system composed of the described subsystem for compilation of detailed
information and an analytical plotter-based control densification subsystem,
represent an economical and effective variant well-suited to the needs of an
integrated multipurpose cadastral information system, due to the ease with
which it can be exploited by various users, and due to the flexibility in its
organization which permits its adaption to a fully centralized cadastral
system as well as to a cadastral system administratively organized into a
network with the activities distributed between the central office and the
regional offices of the country (van Wijk, 1982). It should be underlined
that a stereo-orthophoto-based compilation subsystem whose stereo-orthophoto
generating components do not have the capability to compile the necessary
auxiliary digital information on terrain elevation, and which perform the
printing of the orthophoto and the stereomate in a sequential mode,
| represents a substantially restricted alternative. In this case the optimal
configuration of the subsystem is upset by the need for some additional
components for generation of digital terrain models or profiles, and to a
lesser degree by the sequential instead of the simultaneous generation of the
orthophotos and stereomates.
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These examples of possible configurations of on-line photogrammetric
information compilation systems, although by no means exhaustive, are
sufficiently demonstrative of the capability of analytical photogrammetry to
satisfy practically any requirement that may be posed by a geo-coded
information system. It is evident that, by careful system analysis, a proper
selection of hardware and software can be made, and the optimal version of
the compilation system determined. However, these examples also indicate
implicitly the need for further development of procedures, based on the
mathematical tools of operations research, that will enable both the system
designers and the users to objectively evaluate the advantages and
deficiencies of various hardware configurations and software designs.
SE. AIR WE oem CNN. ONES We Vu
INSTRUMENTATION FOR PHOTOGRAMMETRIC DIGITAL IMAGE PROCESSING
There are four categories of images or records which could be considered as
carriers of input information for photogrammetric processing and analysis:
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- original analog images (e.g. frame camera photographs)
- original digital images (e.g. array camera records)