# Scripts for simulating wide-field-of-view satellite measurements of top-of-atmosphere radiation fields


## Overview
These scripts form the basis of the analysis in "Sampling the diurnal and annual cycles of the Earth’s energy
imbalance with constellations of satellite-borne radiometers" by Hocking et al., 2024.

The code implements an idealised framework for satellite observations of top-of-atmosphere radiation.
Individual satellite orbits can be selected by choosing appropriate inclination, altitude and right ascension of the ascending node.
The footprint of the satellite determines the wide-field-of-view measurement at each measurement time.
The measurement time series are then processed to compute global annual means.

## Prerequisites
The python scripts rely on the libraries used in the environment file `./environment.yml`.
As input data, the scripts expect hourly TOA fluxes from the Clouds and Earth's Radiant Energy System (CERES) SYN1deg data product.
These files should be placed in `./Data/` according to the format in `./experiment/config.py`.
The processing also requires an installation of the Climate Data Operators (CDO) tool set, version 2.3.0 or later.

## Language
Python

## File description
- `./README.md` - This document.
- `./environment.yml` - Python environment specifications.
- `./bin_satm_to_toagrid.py` - Process satellite measurements by binning them on a chosen grid.
- `./earth.py` - Central script containing Earth class, for framework of the radiation fluxes.
- `./measure_file_to_nc_sgp4sat.py` - Measure radiation from input file and save measurements to output file.
- `./process_satm_to_gridweights.py` - Process satellite measurements to determine gridded distribution.
- `./satellite.py` - Central script containing satellite classes, for framework of measurement of Earth instances.
- `./smooth_file_with_satellite_footprint.py` - Compute the convolution of the input file with the satellite footprint.
- `./split_CERES_files.py` - Convenience script for preparing input data files.
- `./unitsconstants.py` - Collection of units and constants
- `./ceres_reference` - Contains scripts to create CERES reference files, which are used in the processing of satellite measurements.
- `./diurnalcycle` - Contains script to restructure input file in terms of local solar time, instead of e.g. GMT.
- `./experiment` - Contains scripts to compute the measurements for a set of satellites.

## Pipeline
First, prepare the computing environment and the necessery input files according to the prerequisites.

In `./ceres_reference`:
- Execute `make_ceres_ref_files.py`.

In `./experiment`:
- Execute `main.py`.
- Execute `merge_day_to_year.py`.
- Execute `make_singlesat_annualmean.py`.
- Execute `make_combo_annualmean.py`.
- Execute `make_combo_annualmean_fillpoles.py`.

The output will be created in `./experiment/fullperiodoutput`, `./experiment/fullperiodoutput_filledpoles` and `./experiment/singlesat_output`.

## Citation
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## References
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## Comments
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## Authors
Thomas Hocking

## Contact information
Thomas Hocking

Department of Meteorology, Stockholm University, Stockholm, Sweden

thomas.hocking [at] misu.su.se

## Publisher
Bolin Centre Code Repository

## Version
1.0.0

## Project URL
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## DOI
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## License
Distributed under the MIT license. See the LICENSE text for more information.

## Publication date
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