Remote Sensing Data Interpretation of FCC Bands on 14th June 2000

Play an AI-generated podcast conversation about this lesson

What is the main difference between dry snow and wet snow?

Dry snow melts faster than wet snow.

Dry snow contains only ice particles, while wet snow contains ice particles and free liquid water. (correct)

Wet snow has a higher dielectric constant than dry snow.

Wet snow has a lower density compared to dry snow.

What is the typical range of snow densities for fresh or new snow?

100-150 kg/m3 (correct)

50-100 kg/m3

200-600 kg/m3

500-700 kg/m3

How does snow density change with the age of the snowpack?

Snow density decreases with the age of the snowpack due to increased air content.

There is no change in snow density with the age of the snowpack.

Snow density remains constant regardless of the age of the snowpack.

Snow density increases with the age of the snowpack due to compaction and thermal metamorphism. (correct)

What does SWE stand for in the context of snow?

Snow Water Equivalent Signup and view all the answers

What is the range of the dielectric constant for snow?

1.2-4.0 Signup and view all the answers

How are the thermal properties of snow important in relation to melting and runoff?

The thermal properties influence phenomena such as melting and runoff. Signup and view all the answers

What happens to snow reflectance in the near-IR region as grain size (or age) increases?

Decreases Signup and view all the answers

How does cloud cover impact the reflectance of snow?

Converts direct radiation to diffuse radiation Signup and view all the answers

What impact does depth have on the visible wavelength reflectance of snow?

Decreases it Signup and view all the answers

In which spectral range has potential been shown for snow/cloud discrimination?

1.55 - 1.75 micro m Signup and view all the answers

What happens to snow reflectance in the visible and near-infrared region compared to cloud reflectance?

Cloud has higher reflectance Signup and view all the answers

How does melting state affect the albedo of snow?

Has no direct effect Signup and view all the answers

Why are NDSI values in shadow and non-shadow regions the same?

Possibly due to reflectance from diffuse radiation in shadow areas. Signup and view all the answers

What is the purpose of using AVNIR-2 in satellite observations over glaciers?

To study the electromagnetic properties of snow in thermal infrared spectrum. Signup and view all the answers

Why does the reflectance of dry snow not exceed 1% in the thermal infrared region for grain sizes above 100 mm?

Due to high emissivity of dry snow. Signup and view all the answers

What range does the emissivity of dry snow typically fall within in the thermal infrared region?

0.965 to 0.995 Signup and view all the answers

Why is a stepwise method required to estimate the emissivity of snow over a spectral region of interest?

Because direct measurement of emissivity is not feasible. Signup and view all the answers

What does ε represent in the context of the text?

Ratio of emittance of a blackbody to that of a sample at the same temperature. Signup and view all the answers

Why is the reflectance of snow in the SWIR band very low?

Ice has a high absorptive coefficient in the SWIR band Signup and view all the answers

What characteristic of snow makes automated snow cover mapping difficult during winter?

Presence of mountain shadows Signup and view all the answers

Why are water clouds and ice clouds more strongly reflecting than snow in the SWIR region?

Water is less absorptive than ice in the SWIR region Signup and view all the answers

How can the problem of automated snow cover mapping in snow-covered regions be partially solved?

By using the Normalized Difference Snow Index (NDSI) Signup and view all the answers

What advantage does utilizing middle infrared have for discriminating between snow and cloud?

It enhances snow reflectance in the SWIR region Signup and view all the answers

Why is NDSI useful for snow-cloud discrimination?

It compares SWIR Reflectance with visible reflectance Signup and view all the answers