Advertisement
comparator, specialized analog filtering shapes the return signal originating from the output of the
preamplifier.
Parameter
Bandwidth
Detector
Virtual Detector size
Detector Bias Voltage
Preamp Noise Floor
Transimpedance Gain
Noise Equivalent Power 12 nW rms
Background Light
LIDARLite has been designed to operate effectively under a variety of indoor and bright outdoor solar
background lighting conditions. The internal optical absorption filter in combination with the detector spectral
response provides a transmission band from 800 nm to 1000 nm. Outdoors, this Spectral window allows
roughly 14% of the total solar Irradiance to pass to the detector. Assuming a solar constant of roughly 1 KW
per meter², and a full receiver field of view of two degrees, we get the following calculated DC solar current
and detector shot noise:
Bright solar optical background = 6 µW
Solar DC current = (6e6 W)(.6 A/W) = 3.6e6 A
Shot noise = ((3.6e6 A)(2)(1.6e19)(1/Hz))1/2 = 1 pA/Hz1/2
Under the bright solar conditions and highly reflective diffuse background calculated above, the equivalent
receiver input noise floor of 1 pA/Hz would increase by a factor of 1.4 resulting in a slight reduction in
maximum range. A 20 nm spectral width narrow band optical filter is available as a factory option and
results in a 10 fold reduction in solar DC current or a (10)1/2 = 3 fold decrease in the resulting noise. The
narrowband filter is of most benefit in applications where specular, "mirror like" reflective surfaces, are
present.
LIDARLite v1 "Silver Label" Manual , Updated: 08/13/15
Receiver specification
50 MHz
PIN diode, 500µm by 500µm , 1.5 pF, 1.8 mm diameter
lens
1 mm – roughly 2X magnification of the package lens
8 V DC nominal. External
1 pA/Hz2
40 K ohm
Advertisement
