Radiometric Calibration Review at St. John Paul II College of Davao

Play an AI-generated podcast conversation about this lesson

What are the two opposite ways in which the atmosphere influences radiance?

Reflection and absorption

Elevation and distance

Path radiance and incident radiation (correct)

Scattering and absorption

How does the atmospheric effects vary with wavelength?

Rayleigh scattering occurs at all wavelengths equally

Rayleigh scattering is more pronounced at shorter wavelengths (correct)

The atmosphere has no effect on wavelength

Rayleigh scattering is more pronounced at longer wavelengths

What does radiometric calibration and correction processes aim to achieve?

To enhance the atmospheric effects on energy recording

To increase the intensity of radiation scattered by the atmosphere

To obtain only the actual surface values (correct)

To reduce the sensor's ability to detect radiation

Which type of radiation involves the energy that illuminates the surface?

Incident radiation Signup and view all the answers

What does a sensor record for each pixel as a digital number?

Intensity of electromagnetic radiation Signup and view all the answers

Why does the irradiance vary throughout the year?

Seasonal differences in solar elevation and Earth-Sun distance Signup and view all the answers

Why is radiometric calibration and correction important in remotely sensed data?

To improve the interpretability and quality of the data Signup and view all the answers

What is the primary purpose of converting an image from radiance to reflectance?

To obtain accurate reflectance values for comparison Signup and view all the answers

Why do the spectral signatures differ when correcting an image from radiance to reflectance?

Because of changes in the atmospheric conditions Signup and view all the answers

Which factor can influence the energy recorded by sensors on aircraft or satellites?

Sun's azimuth and elevation Signup and view all the answers

What is a common reason for conducting radiometric corrections when comparing multiple data sets over time?

Variations in atmospheric conditions Signup and view all the answers

Why is it essential to account for radiometric errors when obtaining ground radiance or reflectance values?

To ensure accuracy by compensating for atmospheric influences Signup and view all the answers

What does Landsat data need in order to carry out the calibration process?

Metadata file Signup and view all the answers

In Landsat data, what does the conversion to reflectance not require?

Conversion to radiance Signup and view all the answers

What is the purpose of converting data from thermal sensors to Brightness Temperature?

Measuring emitted radiance of a surface Signup and view all the answers

Which factor do equations used for rescaling DN data take into account for calibration purposes?

Differences in illumination geometry Signup and view all the answers

What is the unit typically used to express Brightness Temperature?

Kelvin (K) Signup and view all the answers

Which software feature helps Landsat data conversion directly to reflectance?

Radiometric calibration tools Signup and view all the answers

What is the purpose of radiometric calibration in optical remote sensing imagery?

To convert raw image data to a common physical scale based on reflectance measurements Signup and view all the answers

Why is radiometric calibration important for imagery analysis?

It ensures successful conversion of raw image data to known reflectance measurements Signup and view all the answers

What does each pixel in a spectral image have a signature based on?

The object or objects it represents Signup and view all the answers

Which type of calibration ensures that you can use satellite or aerial imagery in mapping applications?

Geometric calibration Signup and view all the answers

What is another term for radiometric calibration?

Radiometric transformation Signup and view all the answers

Why is accurate radiometric calibration essential for successful imagery analysis?

To ensure high-quality and useful results from the images Signup and view all the answers

What is the purpose of atmospheric correction in remote sensing?

To remove the effects of the atmosphere and produce surface reflectance values Signup and view all the answers

In the context of Landsat 8 TIRS, how is the at-satellite brightness temperature calculated?

Using the thermal constant provided in the metadata file Signup and view all the answers

Why is knowledge of atmospheric conditions and aerosol properties important for atmospheric correction?

To accurately apply the correction and produce meaningful results Signup and view all the answers

What do atmospheric models help in accounting for in remote sensing?

Effects of scattering and absorption in the atmosphere Signup and view all the answers

How can satellite data contribute to estimating atmospheric aerosols?

By helping estimate the amount and distribution of atmospheric aerosols Signup and view all the answers

Why do some software packages include special atmospheric correction modules?

To utilize atmospheric radiation transfer models and produce accurate surface reflectance estimates Signup and view all the answers