What is pan-sharpening and how can I create a pan-sharpened image?

Pan-sharpening is a technique that merges high-resolution panchromatic data with medium-resolution multispectral data to create a multispectral image with higher-resolution features.

This page provides details on pan-sharpening Landsat 7 data: Panchromatic Image Sharpening of Landsat 7 ETM+. The process will be similar for Landsat 8 data (band file names will differ).