CTX Polar CRS Toolbox

CTX Polar CRS Toolbox is a QGIS plugin that automatically detects and fixes incorrect scale factors in the custom PolarStereographic Mars coordinate reference system used in Mars Reconnaissance Orbiter (MRO) CTX images.

Features

Automatically corrects +k or +k_0 scale factor to 1.0 in CTX raster CRS.
Runs silently when rasters are added to QGIS.
Includes a Processing Toolbox algorithm ("CRS checker") for bulk correction.
Adds a plugin menu action to scan and fix layers on demand.

Plugin Information

Name	CTX Polar CRS Toolbox
Author	Quentin Betton
Email	quentin.btn45@gmail.com
Version	0.2
Minimum QGIS Version	3.0
Category	Analysis
Tags	python
Experimental	Yes
Repository	GitHub Repository
Issue Tracker	Submit Issues

How It Works

When a raster layer with the CRS named PolarStereographic mars is added to the project, the plugin:

Reads the PROJ string.
Checks for the +k or +k_0 parameter.
Overrides the value to 1.0 if needed.
Assigns the modified CRS back to the layer.

Users can also manually trigger this process from the Plugins menu or using the CRS checker algorithm under the CTX CRS Toolbox provider in the Processing Toolbox.

Usage

Automatic: Add CTX rasters with custom polar CRS — the plugin checks and fixes them on the fly.
Manual: Go to Plugins > CTX Polar CRS Toolbox > Run CRS Checker to fix all loaded layers.
Processing result messages will appear in the QGIS message bar.

Installation

Download or clone the plugin from GitHub.
Use Plugins > Manage and Install Plugins > Install from ZIP.
Browse and select the ZIP file to install.
Activate the plugin in the plugin manager.

License

This plugin is licensed under the GNU General Public License v2 or any later version.

Support

Please submit issues via the GitHub Issue Tracker.