Atmospheric remote sensing toolkit

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BRG The University of Queensland
Fundamentals

- Main page
- Pre-processing
  - Image acquisition
  - When to correct
  - Correction types
    - Radiometric
    - Atmospheric
    - Geometric
  - Masking
- Field data collection
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- Change and trends
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# Radiometric corrections

### Convert relative digital-number to at-sensor radiance

Raw spectral signature (digital numbers) | Physical unit of measurement spectral signature (spectral radiance [watts/m2.μm])

Conversion to at-sensor radiance is needed in pre-processing if the image is to be used for:

- Calculation of biophysical variable is required (e.g. temperature, absorption)
- Multi-date mapping of biophysical variables
- Using field measured spectral-signature libraries to process data

Converts relative sensor measurement (digital-numbers) to an absolute physical unit of measurement AT THE SENSOR: (e.g. spectral radiance [watts/m2.μm] ).

Conversion equation is established for each band(λ) pre-launch and in some cases updated post-launch: At-sensor spectral radiance λ = [gain λ * DN λ] + offset λ