About I/O, synchronization, and measurement
10
If the TemperatureLinearMode is Off, then the camera provides registers that can be
used to convert signal values to temperature. For each measurement range (or gain
mode) there is a set of register values that is used for this conversion.
The conversion from the corrected signal S to the temperature T
[K]
is performed using the
external RBFO values for the selected lens and gain mode. The signal-to-temperature
mapping is calculated using the equation
ln(x) is the base-e logarithm of the x parameter, and S corresponds to the 14-bit pixel
value.
Register name Type
R Integer
B Float
F Float
O Float (handles only positive vales)
OInt Integer (same as O but handles negative values)
Please note that these registers will be automatically updated when switching between the
high gain mode and the low gain mode.
The FLIR GEV Demo sample illustrates how to use this conversion formula.
You also have the option to do your own one-point calibration by adjusting the offset value
(register OInt) by pointing the camera at an accurately known temperature. Knowing the
temperature, you can then calculate the offset value and update the OInt register.
The FLIR GEV Demo sample illustrates how to perform this kind of calibration. Please note
that you will need to save the current settings if you want the new offset value to be persis-
tent. Use the command register SensorSetDefaults to set all current settings as power
on defaults.
There are additional registers that also affect the temperature linear output. These regis-
ters are grouped together as Object Parameter registers. These registers only affect the
transformation of detector signal values to temperature values when the camera is in tem-
perature linear mode.
ReflectedTemperature: The estimated reflected background temperature for the target
scene.
ObjectEmissivity: The target scene emissivity factor. The default value is 1.0.
WindowTransmission: The estimated transmission factor for the protective window. The
default value is 1.0.
WindowTemperature: The external window temperature T
win
(in kelvin).
AtmosphericTransmission: The estimated transmission factor for the atmosphere be-
tween the camera and the scene.
AtmosphericTemperature: The estimated temperature T
atm
for the atmosphere between
the camera and the scene.
The correction for scene parameters is extended to include the following parameters:
#T559770; r. AF/30726/30726; en-US
18
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