Scan Pattern

The scan pattern defines the movement of the mirrors. The key parameters of the pattern are the horizontal and vertical fields of view (FoV) as well as the number of scan lines per frame. The frame rate is defined by the total number of scan lines and the oscillation frequency of the mirrors which is fixed and device-spcific.

Table 1. Available fields in blickfeld.system.config.ScanPattern
Field	Type	Default	Unit
horizontal	Horizontal	-	-
vertical	Vertical	-	-
pulse	Pulse	-	-
read_only	bool	false	-
read_only	this is an read_only flag and it will be set if this is a default scan pattern, which can’t be changed or deleted.
frame_rate	optional FrameRate	-	-

Horizontal

This section defines the movement of the horizontal mirror. The mirror moves continuously with its own frequency. Each half-oscillation period of the mirror results in one scan line.

Table 2. Available fields in blickfeld.system.config.ScanPattern.Horizontal
Field	Type	Default	Unit
field_of_view	float	1.57068062	rad
field_of_view	Unit: [rad] – optical field of view of the horizontal mirror. Note: In v2.2* and below, this was defined as a mechanical FoV.

Vertical

This section defines the movement of the vertical mirror within one frame. The mirror moves for from 0 degrees to the configured target FoV (up-ramping phase) and back to 0 degrees (down-ramping phase) with its eigenfrequency. The number of scanlines for each phase can be configured. Due to the dynamics of the mirror, a certain number of scan lines are required to reach the target FoV and then to reach 0 degrees again. Consequently, if the limit is reached, a lower number of scan lines requires a reduced FoV. Thus, a higher number of scan lines allows a larger vertical FoV. The vertical FoV is limited by the optical components.

Note: Due to the time required for one scan line, the rounded even number of scan lines directly scales inverse proportionally with the frame rate.

Table 3. Available fields in blickfeld.system.config.ScanPattern.Vertical
Field	Type	Default	Unit
field_of_view	float	0.87266463	rad
field_of_view	Unit: [rad] – FoV in the center of the frame. Due to the eye shape of the scan pattern, the vertical FoV decreases the outer boundaries of the horizontal mirror.
scanlines_up	uint32	40	-
scanlines_up	Configures the number of scan lines required for the up-ramping phase. During the up-ramping phase, the vertical mirror increases its amplitude from 0 degrees to the target FoV. Default: 200
scanlines_down	uint32	40	-
scanlines_down	Configures the amount of scan lines required for the down-ramping phase. During the down-ramping phase, the vertical mirror decreases its amplitude from the target FoV to 0 degrees. Default: 30

Pulse

This section defines the pattern in which the laser pulses and captures sample points

Table 4. Available fields in blickfeld.system.config.ScanPattern.Pulse
Field	Type	Default	Unit
angle_spacing	float	0.0043633231	rad
angle_spacing	Unit: [rad] – This defines the angle within which the horizontal mirror moves between two laser pulses. This parameter therefore defines the horizontal sampling resolution.

Frame Rate

This section defines the frame rate of a scan pattern

Table 5. Available fields in blickfeld.system.config.ScanPattern.FrameRate
Field	Type	Default	Unit
maximum	optional double	-	Hz
maximum	Read-only parameter for maximum achievable frame rate of the scan pattern

Named Scan Pattern

Temporary container used for config storage TODO Remove when map type is supported.

Table 6. Available fields in blickfeld.system.config.NamedScanPattern
Field	Type	Default	Unit
name	optional string	-	-
scan_pattern	ScanPattern	-	-