The GRASP Package. An overview.

Generalized Retrieval of Atmosphere and Surface Properties

Oleg Dubovik

Laboratoire d'Optique Atmosphérique

Fabrice Ducos

Laboratoire d'Optique Atmosphérique

David Fuertes


A printable version of this document can be obtained here: docgrasp.pdf

This document describes an overview of the GRASP project, its goals and its architecture. If you want to contribute to the development, you may be more interested in the technical documentation.

The source code of this documentation is in the same repository as GRASP open algorithm. If you want to contribute with your corrections, please check how to do it in User documentation chapter.

28 July 2021

Table of Contents

1. Caveat
2. What you will find in this document
3. What you won't find in this document
4. Versioning
1. Introduction
1.1. Scientific background and heritage
1.2. Generalized aspects of GRASP algorithm and package
1.2.1. Generalized approach of numerical inversion
1.2.2. Practical generalization of the algorithm for atmospheric remote sensing
1.2.3. Adaptation of GRASP for general user
1.3. Concept of GRASP software package
2. GRASP software package
2.1. GRASP architecture
2.2. GRASP input and retrieved data
2.2.1. Measurements and retrieved parameters
2.2.2. GRASP inputs
2.2.3. GRASP input data structures
2.2.4. Input text files for running the Scientific Core alone
2.3. GRASP Scientific Core algorithm
2.3.1. Overall structure
2.3.2. Forward model
2.3.3. Numerical Inversion
2.4. GRASP Control Unit
2.4.1. Configuration manager
2.4.2. Controller Module
2.4.3. Abstract input and output drivers
2.4.4. Concrete input and output data drivers
2.4.5. GRASP file organization
2.4.6. External Libraries used by GRASP code
3. Installation
3.1. Introduction
3.2. Hardware requirements
3.3. Operating Systems
3.4. Access to GRASP Open repository
3.5. Building and installing GRASP
3.5.1. Dependencies
3.5.2. Basic installation of GRASP
3.5.3. Advanced compilation
3.6. Running the code
3.6.1. Usage of GRASP: The configuration file
3.7. Code repository and extensions
3.7.1. GRASP Manager
3.8. Known problems
4. How to use GRASP
4.1. How to run the code
4.1.1. Settings file
4.1.2. Retrieved characteristics
4.2. Input module
4.2.1. The SDATA format
4.2.2. Angle definition
4.2.3. How to prepare the photometer data
4.2.4. How to prepare the lidar data
4.3. Output module
4.3.1. The list of GRASP output parameters
4.3.2. GRASP classic output description
4.4. Forward model
4.4.1. How to use the forward model: Derived products and reprocesing data
4.4.2. Synthetic data
4.5. Aerosol modeling in GRASP
4.5.1. Kernels
4.5.2. Models
4.5.3. Chemistry