FLIR Lepton 2.5 - Telemetry Modes

FLIR LEPTON® Engineering Datasheet
The information contained herein does not contain technology as defined by the EAR, 15 CFR 772, is publicly available,
and therefore, not subject to EAR. NSR (6/14/2018).
Information on this page is subject to change without notice.
Lepton Engineering Datasheet, Document Number: 500-0659-00-09 Rev: 203
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In high gain mode, the camera operates in the high gain state only. In low gain mode, the camera operates in the
low gain state only. In automatic gain mode, the camera software automatically selects between high and low
gain states based on the scene conditions and the following user-selectable parameters:
• High-to-low temperature / high-to-low population: The camera transitions to low gain when a
percentage of the pixel population greater than the user-defined population threshold is imaging a hotter
scene temperature than the user-defined temperature threshold
• Low-to-high temperature / low-to-high population: The camera transitions to high gain when a
percentage of the pixel population greater than the user-defined population threshold is imaging a colder
scene temperature than the user-defined temperature threshold
• Gain mode ROI: region of interest used for the calculations used to determine whether the scene
conditions (temperature and population) meet the criteria for a gain switch
Radiometry must be enabled to configure the camera software to automatic gain mode as scene temperature is
used as the metric to determine the gain mode switching behaviour. Note that an FFC is required upon gain
switch for uniformity and radiometric accuracy updates; therefore, the recommended FFC mode for automatic
gain mode is automatic FFC. In automatic gain mode and external of manual FFC mode, the camera will transition
to a different gain mode without an automatic FFC occurring and the user must initiate the FFC utilizing a
telemetry bit (e.g. effective gain state or FFC desired) to determine when the switch occurred and an FFC is
necessary.
3.4 Telemetry Modes
There are three telemetry modes that affect the video output signal:
• Telemetry disabled (default)
• Telemetry as header
• Telemetry as footer
Explicit commands over the CCI select each mode. The contents and encoding of the telemetry data are shown in
Table 2.
Table 3 shows the encoding of the status bits (Telemetry Row A, Words 3 and 4).