cynthium 1.1.0b2

Scientific desktop application for lunar rover traversal planning and terrain analysis.

Cynthium

Scientific desktop application for lunar rover traversal planning and terrain analysis, focused on the lunar south pole.

Cynthium enables loading lunar elevation data (20 m/px LOLA/LRO GeoTIFFs), defining rover traversal paths, and computing terrain statistics along those paths. It is designed for scientific use cases where map resolution, numerical accuracy, and reproducibility are critical.

Features

• Multi-dimensional Visualization: 2D map views and 3D terrain visualisation using GeoTIFF data (LOLA / LRO).
• Advanced Pathfinding: Optimal path routing using A* or Dijkstra, considering distance, terrain slope, solar illumination, meteor flux, and temperature.
• Rover Simulation: Physics-based traversal simulation including energy consumption, velocity, and slope-based hazards.
• Illumination Analysis: Sun position calculation and shadow mapping for specific lunar dates and times using NASA SPICE.
• Site Management: Automated handling of lunar site rasters and data products.
• Data Export: Export traversal statistics and simulation results for further scientific analysis.

Architecture

The application is organised into several subpackages under cynthium.app:

Package	Responsibility
engine	Core algorithms: pathfinding (A*, Dijkstra), illumination (sun position, shadows), rover simulation (dynamics, physics).
rendering	2D heightmap and 3D terrain rendering via pyqtgraph and PyVista.
services	High-level orchestration: site raster management, simulation lifecycle.
ui	PySide6-based graphical interface: map views, sidebar panels, dialogs.
io	Data reading (GeoTIFF) and export (CSV).
utils	Logging and general utilities.

Installation

Prerequisites

• Python 3.12 or newer.

pip Install (from PyPI)

pip install cynthium

Editable Install (from source)

git clone https://github.com/osh3276/cynthium.git
cd cynthium
pip install -e .

Key dependencies include: PySide6, numpy, rasterio, pyqtgraph, PyVista, and spiceypy.

Usage

Launch Cynthium from the terminal:

cynthium

Or equivalently:

python -m cynthium

The main window opens with a sidebar on the left, a 2D map view in the centre, and a menu bar at the top.

Workflow

1. Load a Site — In the sidebar, select a preset lunar site (e.g. Haworth, Shackleton rim, Nobile rim 1). A 20 m/px elevation tile loads automatically.
2. Select a Map Layer — Switch between visualisations: elevation, slope, hillshade, solar illumination, meteor flux, or temperature.
3. Plan a Path — Click on the 2D map to place start and goal points, then click Autopath. The optimal route is overlaid on the map. You can tune pathfinding with weights for slope, sun, meteor flux, and temperature, and choose between A* and Dijkstra.
4. Configure the Rover — Adjust mass, power, wheel friction, and rolling resistance in the rover settings panel.
5. Run a Simulation — Hit Run Simulation to execute a physics-based 1D rover traverse. Results include distance, velocity, traversal time, solar energy received, and feasibility.
6. Inspect in 3D — Switch to the 3D Terrain View tab to see the path draped over the digital elevation model.
7. Export Results — Save simulation statistics as CSV for external analysis.

Troubleshooting

No path found / path too short The start or goal may be on an untraversable pixel (e.g. a shadowed crater interior). Try moving the points to a ridge or sunlit area.

Rover gets stuck on a seemingly gentle slope The friction coefficient determines max climbable slope. Increase friction or reduce rover mass.

Data files not found Cynthium will attempt to download missing files via pooch on first use. Ensure you have an internet connection for the initial fetch.

Related Work

SEXTANT is a MATLAB-based tool with similar capabilities. Cynthium aims to provide an open-source Python alternative with a focus on extensibility, high performance, and modern GIS compatibility.