Scan Patterns
20
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Number of
Scan Lines
(continued)
NOTE:
All units in this equation are in degrees or degrees/second. Be aware that
the
actual
azimuth rate is used in this equation, so if the internal velocity limit as
above is being applied, this is the velocity used to calculate the minimum line count.
NOTE:
There is a special error code for attempted scans with an insufficiently
dense scan pattern: 0x08 = ERROR_SCAN_TOO_SPARSE
The
Region Scan
pattern is a parameterized scan pattern intended to allow a user to
focus in on a subject in the environment and obtain dense 3D data from just that area.
The scan pattern is similar to a standard 'raster' pattern used in many applications, such
as television and computer graphics. The specific pattern used for the RE08 sensor can
be seen in Figure 5-3, which shows the typical trajectory for specified bounds in the
aperture space.
When viewed in aperture space, the raster pattern is scanned over a rectangular region
which is defined by the
Minimum Azimuth, Maximum Azimuth, Minimum Elevation,
and
Maximum Elevation
parameters. The
Azimuth Rate
and
Number of Lines
define the speed
of the scan, and the line resolution within the bounded region.
Note the
Region Scan
is limited to a 180° azimuth window. Hence it will always select
the shortest arc segment out of the
Minimum Azimuth
and
Maximum Azimuth
parameters.
Figure 5-4 – Selected Azimuth Scan Arc for given Min/Max Azimuth Parameters