as-grm / on_class

Repozitorij pripomočkov za "Oceansko navigacijo"

Ocean Navigation with Python

Ocean Navigation involves two main areas of focus:

• Calculations within Voyage Plan,
• Calculations within Celestial Navigation.

Each section comprises various tasks and problems related to marine navigation.

For solving these tasks, you can refer to the Python programs available in this repository. The Skyfield module is used for celestial navigation computations.

Voyage Plan

In marine navigation, the Voyage Plan addresses three key tasks:

1. Mercator Chart Design: How to design a Mercator chart for navigation purposes.
2. Rhumb Line (RL) or Loxodrome Problem: How to compute the course and distance along a rhumb line.
3. Great Circle (GC) or Orthodrome Problem: How to compute the shortest path between two points on the Earth's surface.

Celestial Navigation

Celestial Navigation encompasses several critical tasks:

1. Star Identification: How to identify stars for navigation purposes.
2. Sight Reduction or Intercept Method: How to compute the position of a celestial body from sextant observations.
3. Meridian Passage: How to determine the moment when a celestial body crosses the observer's meridian.
4. Rise and Set of Celestial Bodies: How to compute the rising and setting times of celestial bodies.
5. Compass Deviation: How to correct compass deviations using celestial bodies.
6. Calculated Position with Body Height:
   • With assumed observer position.
   • Without assumed observer position.

Installation Requirements

The recommended method to use this package is by installing the Jupyter Lab environment from Miniconda.

Ensure that the following packages are installed:

• Numpy
• Skyfield
• Astropy
• Basemap
• LaTeX (required for generating star identification maps)

Install these packages using the conda package manager from the conda-forge channel:

$ conda install --file requirements.txt

Important Note: Before running any Celestial Navigation programs for the first time, execute the following program (and restart the kernel afterward):

• nav_tools/refresh_database.ipynb

This program will download the necessary time frame database. Additionally, running any Celestial Navigation program for the first time will trigger the download of two additional astronomical databases.