Lidar

Question 1

Describe the fundamentals of how lidar works

Answer 1

• creates its own electromagnetic energy pulses in the form of a laser
  beam
• records time to return, intensity of the returned electromagnetic
  energy, and phase

Question 2

list the main components of a lidar system

Answer 2

1. scanner
2. GPS system
3. Inertial navigation system

Question 3

Distinguish between laser altimetry and scanning lidar

Answer 3

1. laser altimetry
   - makes height measurements
   - creating individual transects or lines of observations
2. scanning lidar
   - scans from side-to-side creating measurements across the entire swath
   - capable of creating 3D imagery
   - detailed elevation mapping (used or floodplain mapping programs

Question 4

Explain the difference between discrete and waveform lidar

Answer 4

discrete
- measures one or more returns
- produce one or more height measurements for each x, y location
waveform
- does not discretize the returns into individual measurements
- record intensity of returned lidar continuously
- a distribution of return intensities

Question 5

explain the uses of both discrete and waveform lidar

Answer 5

discrete
- detailed elevation mapping
- characterize the vertical distribution of biomass
waveform
- estimate total biomass and its vertical distribution
- measures aboveground biomass (and carbon) at different
places around the world

Question 6

List some of the main applications of lidar data

Answer 6

1. environmental applications
2. bathymetric, or under water
3. mainly used for mapping the shape or morphology or Earth’s
   surface and the objects on it