Ir
12
447
SYMBOL | BIO 21-30
No. | Alpha Presentation Notes
Description {in maps 1:1000 {on-line GP-1
86 | HATCH.PTD 0 ti
Fig.5: Plot of the operator's catalog. Combination between number, alphadescription.
map, on-line plot and photograph
fined objects for each group: i.e. no.80 for undefined gas-pipes and no.70 for undefined
electricity-lines.
In addition to the feature-codes, fixed in the library, it is possible to add some geometri-
cal information to the measurements. These information may be straight line. curve.
arc or symbol.
Some special functions like squaring and hatching of buildings. drawing parallel lines
and the possibility to change the line- and symbol-size scale factor make this program
universal for this task.
Generally the registration is executed by use of the two foot-pedals: the left one for the
pen-up motion. the right one for the pen-down motion. During registration the operator
has to take care of starting and ending segments in a useful manner and has to registrate
every intersection point. even those on a long straight line.
The coordinates of the points are used to be stored in an ASCII-file together with the addi-
tional information on linetype or symbol number, scale-factor, mode and. if necessary.
time.
The ASCII-format requires quite an amount of space. but it is selfdescriptive and easy to
edit.
5. Applicable Information from Aerial Photographs
Compared to all other measurements those made by use of aerial photographs have one main
advantage: They are topical. This should be taken into account for the project Neustadt.
As it is not possible or meaningful to get all required information for a LIS from the
aerial photographs. a solution has to be found to combine the information from existing
maps with those from the photographs. Therefore the geometric correct base for all sec-
tions was taken from the photographs and was correlated with the dependent details from
the graphic sources. The data can be classified in different kinds of visibility:
- the signalized points
For the correlation of the local coordinate system and the aerial block system about 70
points were signalized. 28 of them were used as control points. the others as
tie- and pass-points. The results of the bundle block adjustment did not require any
improvement of the local survey points.
- cadastral and planning information
Boundary and other cadastral information can usually not be seen in aerial photographs.
The same problem occurs with planning data. Exceptions may be buildings and other
topographic elements, being located right on a parcel boundary. as you can often Find
them in urban aeras with single-unit houses (see fig.8). This fact causes that the ca-
