The .hgt file extension is associated with SRTM (Shuttle Radar Topography Mission) data. These files contain elevation data, representing terrain height above sea level. The data is typically stored as signed 16-bit integers in a grid format. Each .hgt file covers a 1x1 degree area of latitude and longitude. The resolution of the data varies, with SRTM-1 data providing approximately 30-meter resolution (1 arc-second) for the United States and SRTM-3 data providing approximately 90-meter resolution (3 arc-seconds) for most of the world. These files are crucial for various applications, including geographic information systems (GIS), mapping, 3D modeling, flight simulation, and scientific research. They allow for accurate representation and analysis of terrain features, enabling tasks such as terrain visualization, slope calculation, watershed analysis, and route planning. The data is often used in conjunction with other geospatial datasets, such as satellite imagery and vector data, to create comprehensive and detailed maps and models of the Earth's surface. The format is relatively simple, making it easy to parse and use in custom applications.