= Leica ALS50-II LIDAR = The ARSF LiDAR system, for data collected in 2009 onwards, is a Leica ALS50-II. This includes a full waveform upgrade for 2010 onwards. The ALS50-II operates with a 8W class 4 laser with radiation at 1064 nm. It works by firing a pulse every 4ns or 9ns and measuring the round trip time to when a reflection is detected. This is then converted into a distance. There are 2 banks of timing cards - each one with 4 cards. This means that it can measure up to 4 independent returns for each pulse (it only uses the 2nd bank of cards when operated at the higher pulse rate). A minimum time separation between two returns means the minimum distance between two returns must be at least 2.7m for them to be counted as independent. == Specification summary == A lot of the system specs can be (and are) changed to tailor for individual flight purposes. If you need to know certain parameters that have been used for a specific flight that are not included in the delivery documents then please [wiki:ContactUs contact us]. The listed parameters here are min/max values - not necessarily used for a specific collection. || Wavelength (nm) || 1064 || || Beam divergence (mr) || 0.22 || || Max FOV (degrees) || 75 || || Laser power || 0-8W (controlled by operator) || || Max rate of acquiring waveform || 120KHz || == Raw data format == In the form of binary "SCN" files, which contains the raw data using compression and bit-masking. Can be viewed using the Leica SCNviewer graphical interface that comes with the Leica processing software. The files contain data records of ~32 bytes for each point. Full waveform has the additional files that contain the digitised waveform (.LWV extension). These are binary and you get separate files per range bank with A or B postfix. == Further Information == For more in-depth and technical information about the sensor and processing please see the following pages. Note that these are written primarily for internal use and so may be technical in nature. === Discrete subsystem === * [wiki:Sensors/LeicaLIDAR/MikesNotes] - Mike's notes on the Leica training course in Aug 2008 (to be digested and turned into real wiki pages at some point in the future). * [wiki:Sensors/LeicaLIDAR/MarksNotes] - Mark's bullet notes on the Leica training course in Aug 2008. * [wiki:Sensors/LeicaLIDAR/MashUp] - The digestion of both sets of notes. === Full waveform subsystem === * [wiki:Sensors/LeicaLIDAR/FWMarksNotes] - Mark's notes on the Full Waveform training Jan 2010. * [wiki:Sensors/LeicaLIDAR/FWEmmasNotes] - Emma's notes on the Full Waveform training Jan 2010. * [wiki:Sensors/LeicaLIDAR/FWMikesNotes] - Mike's notes on the Full Waveform training Jan 2010.