Gunamoi Software

HGT2CSVConvert is a free tool to convert SRTM data in binary HGT files to CSV format files in a windows GUI.  Many GIS programs can open and process SRTM HGT files (for example QGIS).  But sometimes a user may want to view the source data directly in a spreadsheet, and for this purpose a comma-separated text CSV file may be more suitable.  HGT2CSVConvert allows the user to directly convert a HGT file to a CSV file.  But please note that the file created by this method may be too large for some spreadsheet software.  As an alternative to CSV format, users may also select our proprietary "warray" file type for the output file, to obtain a Map Grid Data file suitable for plotting with our MapList-Flat, or MapList-Globe programs. 

HGT2CSVConvert also gives the option to specify a latitude and longitude section to convert, instead of a whole HGT file.  This allows the user to extract a subsection of data from a HGT file to a CSV file, possibly producing a smaller file.  If the user specified resolution (in decimal degrees) does not match the HGT file resolution, HGT2CSVConvert will interpolate altitudes for the specified grid using bilinear interpolation.  If the user specified latitude/longitude section crosses several HGT tiles, HGT2CSVConvert can open multiple HGT files as necessary to complete the task. 

HGT is a binary data file format used to store altitude data derived from the NASA Shuttle Radar Topography Mission (SRTM).  The ground height data (altitude in meters above sea level) in the SRTM digital elevation model (DEM) is stored in multiple binary files, covering most of the earth's landmass (from 56°S to 60°N).  Each binary file contains data for a 1degree latitude by 1degree longitude tile.  Where a map tiles contains no land, only sea, there will be no HGT file.  File names indicate the latitude and longitude of the south-west (bottom-left) corner of the tile.  For example, the file named "S34E150.hgt" contains altitude data for the 1degree grid with SW corner at 34S, 151E.  Files were created in two versions: a grid with 3 second resolution (file size 2.75MB); and a grid with 1 second resolution (file size 24.73MB).  SRTM HGT data files with 3 second resolution (SRTM3) are generally freely available from several sources.  Access to SRTM HGT data files with 1 second resolution (SRTM3) is limited.  HGT2CSVConvert can read either version of SRTM HGT file and process them appropriately.  Read more about SRTM HGT files on Wikipedia. 

Possible sources of NASA SRTM HGT data are:

• Viewfinder Panoramas provides a simple coverage map that allows download of zipped SRTM HGT files with 3 arc second resolution for any location available.
• NASA EarthData search.
• U.S. Geological Survey previously provided SRTM data in HGT format via EarthExplorer, but has now changed to GeoTIFF format which is not supported by this app.

System Requirements:

Windows 7 or later, 32 bit or 64bit versions available.

This is free software and is provided free of charge, 'as is' with no warranty.  No registration required.  There is no installer for this program, just unzip the executable and run it as described below. 

Download the program here.

  SHA1 checksum: 760d415e0dfb48eb1a7d51565c62623549472418

  SHA1 checksum: 0f09d183d0b3c7be3649399939cf96aee7cf90b7

Installation steps:

1. Download the appropriate HGT2CSVConvert zip file from this page (see buttons above).

2. Unzip the HGT2CSVConvert executables to any location and run them directly.  There are no other special install requirements. 

Sample HGT2CSVConvert Screenshot

Please note that the exact look and feel of the program will vary on each computer depending upon the individual user's operating system and theme settings. 

Version History

Version 1.4 released March 2024:

• Minor update to latest code libraries.

Version 1.3 released March 2023:

• Minor update to latest code libraries.

Version 1.2 released May 2022:

• Fix bugs related to wxWidgets Debug Alert at program start on some non-English language machines.
• Ensure output text files are always UTF8 encoded.
• Some minor code optimisation.

Version 1.1 released September 2021:

• Give user the option to proceed in case of missing HGT files, assuming missing files are all sea-level tiles only.

Version 1.0 released September 2021.

This is absolutely free software, provided ad-free and without obligations.
However, should you find it useful, and wish to show your appreciation, you may buy me a coffee via PayPal using the button below:

This page last updated March 2024.
To provide comments and feedback about this web site, or any of the software listed above,
Email the webmaster at software@ gunamoi.com.au.
This web site Copyright © 2024 by Garry Hausfeld, Gunamoi Software.
™ The "Orbiting Roo" image is a registered trademark of Garry Hausfeld.