CH Remote Sensing & Satellite Imagery 3

Question 1

The Lyzenga log-ratio empirical method for satellite-derived bathymetry (SDB) is based on:

Accepted Answer

Logarithmic ratios of water-leaving radiance in two spectral bands calibrated with known depths

Answer

Radar backscatter intensity variations across the ocean surface

Answer

Thermal emission differences between shallow and deep water

Answer

LiDAR pulse travel-time measurement through the water column

Question 2

What minimum spatial resolution is generally required for satellite imagery used in detailed coastal harbor feature mapping?

Accepted Answer

Sub-meter to 1 meter (Very High Resolution class)

Answer

30 meters (Landsat class)

Answer

10 meters (Sentinel-2 class)

Answer

100 meters (MODIS class)

Question 3

MODIS (Moderate Resolution Imaging Spectroradiometer) data is primarily used in hydrographic and oceanographic practice for:

Accepted Answer

Synoptic monitoring of ocean color, SST, and chlorophyll over large ocean areas

Answer

Chart-quality depth measurement in nearshore areas

Answer

High-resolution detection of small coastal features

Answer

Measuring nearshore significant wave height

Question 4

Ground truth depth data is essential in satellite-derived bathymetry (SDB) because it is required to:

Accepted Answer

Calibrate the empirical spectral-to-depth model and validate its accuracy

Answer

Determine the satellite's orbital altitude and velocity

Answer

Perform atmospheric correction of the imagery

Answer

Convert the raster depth grid to vector contour format

Question 5

Orthorectification of satellite imagery is performed to:

Accepted Answer

Remove geometric distortions caused by terrain relief displacement and sensor viewing geometry

Answer

Enhance image contrast and sharpen edge features

Answer

Merge multispectral bands into a single color composite

Answer

Convert the image coordinate system from geographic to projected

Question 6

Satellite radar altimetry contributes to hydrography and geodesy primarily by providing:

Accepted Answer

Sea surface height measurements used to model mean sea level and the marine geoid

Answer

High-resolution seafloor mapping through deep ocean water

Answer

Real-time identification of vessel traffic and ship positions

Answer

Coastal vegetation mapping for wetland delineation surveys

Question 7

Which of the following satellite datasets is freely available and widely used for large-area coastal monitoring and satellite-derived bathymetry research?

Accepted Answer

Sentinel-2 (ESA Copernicus program)

Answer

WorldView Legion (Maxar)

Answer

Planet SkySat

Answer

GeoEye-1 (Maxar)