Working with LiDAR Intensity

Note: this page is currently a work in progress which will be updated as more progress in this area is made

As well as the time / range of the echo return, the system also measures the intensity (peak power) of the echo. Currently this value is not calibrated nor comparable along the flight line. This is due to the automatic gain control of the system (AGC), where the echo power is amplified by different amounts dependant on the return strength. This can result in a 'striping' effect in the intensity images. Although the gain value changes along the flight line it is consistent for a return pulse, that is, for a recorded waveform the same gain value is used along the entire waveform. The AGC value needs to be exported from ALSPP and is saved in the User Data' and Point Source ID` field for each point. The value is constant for a given pulse, that is, for a recorded waveform the same gain value is used along the entire waveform.