Abstract An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped mu J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited by optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micro pulse lidar systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.
A eye safe laser radar system operating in the visual spectrum for profiling clouds and aerosols comprising: a laser transmitter for transmitting an outgoing laser beam at a wavelength in the range of 0.4 to 0.8 μm, operating at a pulse energy of less than 40 μJoules and a pulse repetition rate of greater than 1000 hertz; means for expanding and collimating said outgoing laser beam; receiver means for receiving an incoming laser beam, said incoming laser beam being a backscatter of said outgoing laser beam from atmospheric targets, said incoming laser beam being directed to a photon counting signal detector means; means for collimating and filtering said incoming laser beam prior to said photon counting signal detector means; means for acquiring and processing a signal from said detector means to profile atmospheric clouds and aerosols.
Claim 2
Dependent Claim
136 words
A eye safe laser radar system operating in the visual spectrum for profiling clouds and aerosols comprising: a laser transmitter for transmitting an outgoing laser beam at a wavelength in the range of 0.4 to 0.8 μm, operating at a pulse energy of less than 40 μJoules and a pulse repetition rate of greater than 1000 hertz; means for expanding and collimating said outgoing laser beam; receiver means for receiving an incoming laser beam, said incoming laser beam being a backscatter of said outgoing laser beam from atmospheric targets, said incoming laser beam being directed to a photon counting signal detector means; means for collimating and filtering said incoming laser beam prior to said photon counting signal detector means; means for acquiring and processing a signal from said detector means to profile atmospheric clouds and aerosols.
Claim 3
Dependent Claim
15 words
The device of claim 1 wherein said laser transmitter is a diode pumped Nd:YAG laser.
Claim 4
Dependent Claim
15 words
The device of claim 1 wherein said laser transmitter is a diode pumped Nd:YLF laser.
Claim 5
Dependent Claim
20 words
The device of claim 1 wherein said photon counting signal detector means is a Geiger mode Avalanche Photo Diode detector.
Claim 6
Dependent Claim
13 words
The device of claim 1 wherein said receiver means comprises a Cassegrain telescope.
Claim 7
Dependent Claim
26 words
The device of claim 4 wherein said means for acquiring and processing a signal from said detector means comprises a computer with a multichannel scaler card.