Downloading Free Global & Regional Topographic Data on OpenTopography

In this tutorial, we will cover how to access and download global and regional topographic data and derived products on OpenTopography. This platform offers two primary methods for accessing data, ensuring you can find exactly what you need.

Data Access Methods

On OpenTopography, you can access data in two ways:

• Data Catalog: From the data drop-down menu, you can navigate to the data catalogue, which provides a comprehensive list of all high-resolution global and regional topography datasets available. You can click on a dataset to download and access the associated data products.
• Find Data Map: Alternatively, you can use the find data map from the data drop-down. Zooming in on the map reveals polygons representing the available high-resolution topography datasets.

Viewing Available Data Sets

To explore the extent of available global and regional datasets, head to the ‘Select a Data Set’ drop-down under data sources. Hovering over a dataset will display its full name, and you can select a dataset to view its area of coverage. For instance, the Shuttle Radar Topography Mission (SRTM) provides global coverage.

Selecting Your Area of Interest

Once you’ve identified the dataset you want to explore, zoom in on the map to navigate to your area of interest. For example, you might select a region near Mexico City. Click the ‘Select a Region’ box and draw a rectangle over the area for which you want to download data.

Available Data Sets for Your Region

At the bottom of the page, ensure the ‘Global and Regional DEM’ tab is selected. This section will list all available datasets covering your selected region. By clicking the plus sign next to a dataset, you can expand and view more information.

Downloading Data

Click the blue button next to the dataset you wish to access. For datasets like Copernicus, the Digital Elevation Model (DEM) resolution is indicated in the name. For instance, SRTM GL three has a ninety-meter resolution, while GL one has a thirty-meter resolution with ellipsoidal vertical datums available for both SRTM and ALOS. In this example, we will use the thirty-meter SRTM data.

Dataset Download Page

After clicking the button, you will be directed to the dataset download page, which contains detailed information about the dataset and its raster resolution. You can further refine your selected area if needed using the select a region feature or manually enter selection coordinates.

Output Formats and Visualizations

Under ‘Data Output Formats,’ select the output type for your digital elevation model. By default, GeoTIFF is selected, but you also have the option to choose ASCII or IMG formats. Additionally, you can create derived image visualizations such as hillshade, color relief, slope, aspect, and roughness.

Customizing Your Visualizations

Select the boxes for the products you would like to generate. You will have options to adjust vertical exaggeration, hillshade light source, and color maps for color relief. You can also choose the output format (TIFF or IMG) and opt to create additional Google Earth KMZ files.

Job Submission and Notifications

In the ‘Job Description’ section, add a job title and description, enter your email address, and click submit to initiate processing. You will receive an email notification once the job has finished running, so there’s no need to keep the page open.

Accessing Generated Images

When the job has completed, you can download the generated images under ‘Visualization Products.’ Click on the file to download the image or access the KMZ file. You can also view the image in a pop-up map viewer, where clicking on it will open it in full resolution in a new window.

FAQ

What types of data can I download from OpenTopography?

You can download various global and regional topographic datasets, including SRTM, ALOS, and Copernicus data.

Can I customize the output format of the data?

Yes, you can choose from several output formats, including GeoTIFF, ASCII, and IMG.

How will I know when my data is ready for download?

You will receive an email notification once your data processing job has finished running.