Use of a multibeam transmitter for significant improvement in signal-dynamic-range reduction and near-range coverage for incoherent lidar systems

It is very difficult for both detectors and data acquisition systems to cope with the enormous signal dynamic range of incoherent lidar systems. The high power of the near-range atmosphere-backscattered radiation may cause serious problems to detectors. If the detector can endure the high power, the dynamic range of the output electric signal still remains a problem. To solve the problems, this paper suggests using a multibeam transmitter instead of a single-beam transmitter. With a multibeam transmitter a significant reduction of the signal dynamic range can always be achieved simultaneously with good near-range coverage even under different atmospheric conditions. Numerical simulations for a differential absorption lidar (DIAL) system measuring ozone in the lower troposphere below 3 km show the advantage of using a three-beam transmitter rather than a single-beam transmitter.