.HGT File Extension
What is an HGT file?
The .HGT file extension is associated with the SRTM (Shuttle Radar Topography Mission) data, which provides digital elevation models (DEMs) of the Earth’s surface.
These files contain elevation data captured by radar aboard the Space Shuttle Endeavour during its 11-day mission in February 2000. The mission aimed to map 80% of Earth’s landmass using radar interferometry techniques.
More Information.
The primary purpose of SRTM was to create a comprehensive dataset of global elevation to enhance scientific research, improve mapping accuracy, and support various applications requiring precise elevation data.
The mission utilized radar technology aboard the Space Shuttle Endeavour to collect topographic measurements, which were later processed into digital elevation models.
Origin Of This File.
SRTM, a mission led by NASA and the National Geospatial-Intelligence Agency (NGA) in 2000, aimed to collect elevation data globally using radar interferometry.
This ambitious project mapped Earth’s terrain with unprecedented accuracy, producing datasets that were made freely available to the public.
File Structure Technical Specification.
.HGT files typically store elevation data as a grid of height values, structured in a specific format. Each file covers a square area of 1° latitude by 1° longitude, containing elevation values at regular intervals.
The elevation data is represented in integer format, with each value corresponding to the height above sea level in meters.
The structure of .HGT files are straightforward, consisting of a header section that includes metadata such as file size and resolution, followed by a matrix of elevation values organized row by row.
These files are binary, compact, and designed for efficient storage and retrieval of elevation data.
How to Convert the File?
Converting ‘.HGT’ files to other formats can be achieved through various Geographic Information System (GIS) software tools without needing to delve into code. Here’s how:
1. Using GIS Software:
- QGIS: Open QGIS and use the ‘Raster’ menu to import the ‘.HGT’ file. Once imported, you can use the ‘Raster’ > ‘Conversion’ > ‘Translate’ tool to convert it to formats like GeoTIFF or ASCII grid.
- ArcGIS: In ArcMap or ArcGIS Pro, add the ‘.HGT’ file to your project through the ‘Add Data’ button. You can then use the ‘Copy Raster’ tool to convert it to other formats compatible with ArcGIS.
- Global Mapper: Open the software and use the ‘File’ > ‘Open Data File’ option to import the ‘.HGT’ file. Global Mapper provides options under the ‘File’ > ‘Export’ menu to convert the file to various formats.
2. Format Conversion:
- Choose the desired output format (e.g., GeoTIFF, ASCII grid) based on your application’s requirements.
- Ensure to configure conversion settings such as projection, resolution, and data type as needed for your project.
Advantages And Disadvantages.
Advantages:
- Accuracy: SRTM data provides high-resolution elevation models suitable for detailed terrain analysis.
- Global Coverage: With nearly global coverage (excluding polar regions), .HGT files offer data for almost any location on Earth.
- Free Accessibility: The data is freely available, promoting widespread use in both commercial and non-commercial applications.
Disadvantages:
- Resolution Limitations: While generally high-resolution, .HGT files may not capture very fine details of terrain features.
- Limited to Earth’s Surface: These files are specific to Earth’s topography and cannot be used for extraterrestrial mapping.
- Processing Requirements: Handling and processing large .HGT datasets may require significant computational resources.
How to Open HGT?
Open In Windows
- Use GIS software like QGIS or Global Mapper, which support .HGT files directly.
- Alternatively, convert .HGT files to GeoTIFF using GDAL for compatibility with various Windows-based applications.
Open In Linux
- GDAL, a widely used command-line tool in Linux environments, supports .HGT file conversion and manipulation.
- QGIS and other open-source GIS software on Linux platforms natively support .HGT files.
Open In MAC
- Utilize QGIS or GDAL, both available for MacOS, to open or convert .HGT files.
- Mac-specific GIS applications can also handle .HGT data effectively.
