Overview

The Rugged library aims at providing direct and inverse location to perform full ortho-rectification of images and correlation between sensors observing the same area.

Rugged, a pure Java library, depends only on the Java Standard Edition version 8 (or above), Orekit version 11.2 (or above) and Hipparchus version 2.1 (or above) libraries at runtime.

External dependencies

Runtime component

This component is required to compile and run Rugged:

• Orekit
  Copyright © CS GROUP
  License: Apache License, version 2.0
  Reference: Orekit

• Hipparchus
  Copyright © Hipparchus project
  License: Apache License, version 2.0
  Reference: https://www.hipparchus.org/

Test-time component

This component is required for testing purpose only:

• JUnit 4
  Copyright © Erich Gamma and Kent Beck
  License: Common Public License, version 1.0
  Reference: http://www.junit.org/

Design & Implementation

General concepts

As a an intermediate level library, Rugged aims at being used in very different contexts which cannot be foreseen, from quick studies up to critical operations.

The main driving goals for the development of Rugged are:

• validation
• robustness
• maintainability
• efficiency

These goals lead to design and coding guidelines including:

• comprehensive test suite for high level of coverage
• automated checking tools for robustness
• consistent coding style for readable, clear and well documented code
• wide use of immutable objects for efficiency

Features

• Direct/inverse location
• Refinement
• Can support several types of Digital Elevation Models, including user-provided models
• Several intersection models algorithms available
• Can propagate orbit by itself for preliminary mission analysis or data generation
• Can propagate attitude by itself for preliminary mission analysis or data generation
• Very fast
• Both modern and legacy models for Earth rotation
  • Lieske (1976), Wahr (1980)
  • Mathews, Herring, Buffett (2002)
  • Capitaine (2006)
• Complete set of corrections applied for greater accuracy
  • δΔψ, δΔε on precession nutation (about 3m correction since 2013, steadily increasing)
  • ΔUT₁, lod on proper rotation (can theoretically reach up to 400m)
  • u, v pole wander (polhody), (about 15m correction)
  • light time correction (about 1.2m)
  • aberration of light correction (about 20m)
  • line-of-sight curvature in geodetic coordinates, (0m at nadir, 10m at 30° dive angle, hundreds of meters for skimming los)
  • atmospheric refraction
• Not limited to Earth
• Highly portable (Linux, Windows, MacOSX, ...)

Localized in several languages

• Danish
• English
• French
• Galician
• German
• Italian
• Norwegian
• Romanian
• Spanish