Method

Sensor

Type

Accuracy

Controlling Factors

Advantages

Drawbacks

Scope of Application

Imaging

Microwave or SAR sensor

Active

Relatively low

Image resolution, slicks, waves, fronts, weather condition

- Applicable over large areas - Unaffected by cloud cover

- Relative low

accuracy

Bathymetry derivation from open oceanic waters

Non-

imaging

Radar Altimetry

Active

Very low accuracy

Elastic thickness of the lithosphere and/or crustal thickness, sediments

Global coverage, needs only simple altimetry with no iono/tropo-sphere measurement

Possible over a limited wavelength band

Coarse bathymetry derivation for oceans

Non-

imaging

LIDAR

Active

≈15 cm

Water clarity or turbidity, bed material, surface state

Wide depth range; concurrent measurement not essential

- Expensive - Limited swath width

Varied aquatic environments of narrow range

Imaging

Optical (analytical)

Passive

Relatively high

Water quality (clarity or turbidity), cloud cover, atmospheric conditions

- Based on physical process - Relatively higher accuracy

- Complex execution as input parameters are required - Real-time in-situ data essential

Turbid and shallow inland waters, estuaries, river channels

Imaging

Optical (empirical)

Passive

Varying accuracy

Atmospheric calibration, water turbidity, bottom reflectance

- Simple to execute - Accurate at definite depth

- Limited depth - Accuracy lower at a larger depth - Real-time ground truth essential

Near shore and coastal waters, open waters

Imaging

Video

Passive

Relatively high

Image resolution

- Capable to produce minor bathymetric change

Restricted area Bathymetry along profiles

Intertidal zone and estuaries