![]() To perform Geographic
Measurements
The
measurement options described here are calculations of area, perimeter,
length, and distance between any two points. The measurement
operations can be performed
by Indicationnt
over existing geographic
entities (points, lines, or polygons), or
by Edition, where lines, points and polygons are not
part of any IL defined in the project, they are simply drawn on the screen
during the measurement operations.
Following you will see
how to perform both types of measurements. ·
Measurement
by Editing
Measurement by
Indication
The operation of measuring entities by indication, over one existing
infolayer, requires the existence of at least one IL of the models: thematic,
numeric, cadastral, or network, and some digitized
entity. Otherwise, the option of type indication will be disabled. Polygon Area and Perimeter Measurement
To calculate the area and
perimeter of any polygon (closed polygon) in thematic or cadastral maps, load
an IL that has that type of entity.
Repeat the procedure above to see the
data about the other polygons. OBS: The
system searches for the polygon that is closest to the mouse position in the
active display, in case it doesn't find one, the message "Polygon not found" will be presented, click on Continue to
proceed. Measuring Line length
To calculate the length
of any line represented in thematic, cadastral, network,
or even numeric (contour lines) maps, load an IL that has that type of
entity.
Using only the left
button of the mouse click once over the line in the active display,
and it will be selected with a different color (see the figure below). Note
that the values are presented in the lower bar of the window
"Measurements" (see the figure below).
Repeat
the procedure above to see the length of other lines. OBS: The system searches for the line that is closest to the position of the mouse, in case it doesn't find one, the message "Line not found" will be presented. Click on Continue to proceed. Measuring distance between points
To calculate the distance
between any two points (the entity point, a point over a line,
or even a point defined by the proximity of the mouse to a line)
represented in thematic, cadastral or network maps, or even numeric (contour
lines and spot heights), load an IL that contains these sort
of entities.
Repeat with two other clicks to see the
distance between two selected points. OBS: The system searches for the line that is closest to the position of the mouse, in case it doesn't find one, the message "Line not found" will be presented. Click on Continue to proceed.
Measurement by Editing
The operation of measuring entities by edition does not require any
type of Infolayer loaded or visible in the drawing area. In this case we can
even use a background image, over which the measurements will be performed. The
digitized entities are not saved in any infolayer, being visible only when
the measurement window is open. Measuring the Area and Perimeter of edited polygons
To calculate the area and
perimeter of any edited polygon (closed polygon) it is not required the
visualization of any IL on the screen. the polygons
will be edited as closed lines (islands), that is, when finishing the edition
the first and the last points will be connected automatically.
Measuring the Length of edited lines
To calculate the length
of any edited line it is not required the visualization of any IL on the
display. the lines will be edited as open lines
(arcs).
Repeat the last two steps to see the
length of other lines. Measuring the Distance
between points
To calculate the distance
between any two points on the drawing area it is not required the
visualization of any IL on the screen.
NOTE: To perform the measurement for
other points just click on any two other points in the active display. Every
time you define the second point the value for the distance is automatically
presented.
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