# Welcome to Pyspectral’s documentation!

Given a passive sensor on a meteorological satellite PySpectral provides the relative spectral response (rsr) function(s) and offers some basic operations like convolution with the solar spectrum to derive the in band solar flux for instance. The focus is imaging sensors like AVHRR, VIIRS, MODIS, ABI, AHI and SEVIRI. But more sensors are included and if others are needed they can be easily added. With PySpectral it is possible to derive the reflective and emissive parts of the signal observed in any NIR band around 3-4 microns where both passive terrestrial emission and solar backscatter mix the information received by the satellite. Furthermore PySpectral allows correcting true color imagery for background (climatological) Rayleigh scattering and aerosol absorption.

The source code can be found on the github page.

With PySpectral and SatPy (or previously mpop) it is possible to make RGB colour composites like the SEVIRI day solar or the day microphysical RGB composites according to the MSG Interpretation Guide (EUMETSAT). Also with SatPy integration it is possible to make atmosphere corrected true color imagery.

- Satellite sensors supported
- Installation
- Static data
  - The spectral response data
  - Look-Up-Tables for atmospheric correction in the SW spectral range
  - Configuration file
- Usage
- Simple plotting of spectral responses
- Example with SEVIRI data
  - Integration with SatPy
- Definitions and some radiation theory
  - Symbols and definitions used in PySpectral
  - Constants
  - Central wavelength and central wavenumber
  - Spectral Irradiance
  - TOA Solar irridiance and solar constant
  - In-band solar flux
  - Planck radiation
  - The inverse Planck function
- Derivation of the 3.7 micron reflectance
  - Brightness temperature to spectral radiance
  - Determination of the in-band solar flux
  - Derive the reflective part of the observed 3.7 micron radiance
  - Derive the emissive part of the 3.7 micron band
- Atmospherioc correction in the visible spectrum
- Formatting the original spectral responses
  - Convert from original RSR data to pyspectral hdf5 format
  - Conversion scripts
- The `pyspectral` API
  - Blackbody radiation
  - Spectral responses
  - Solar irradiance
  - Near-Infrared reflectance
  - Rayleigh scattering
  - Utils

# Indices and tables

- Index
- Module Index
- Search Page