Searching and Downloading Satellite and DEM Data

Practical Guide: Searching and Downloading Satellite and DEM Data

1. Introduction

Satellite imagery and Digital Elevation Models (DEMs) are crucial for various applications in GIS, including environmental monitoring, urban planning, and natural resource management. This guide will walk you through the steps to search for and download satellite and DEM data.

2. Identifying Data Sources

There are several platforms where you can find satellite imagery and DEM data. Here are some popular sources:

• USGS Earth Explorer: A comprehensive source for satellite imagery and DEMs.
• NASA Earthdata: Offers a variety of satellite datasets.
• Copernicus Open Access Hub: Provides access to Sentinel satellite data.
• OpenTopography: A platform for high-resolution DEM data.

3. Searching for Satellite Data (Using USGS Earth Explorer)

A. Access Earth Explorer

1. Visit the Website: Go to USGS Earth Explorer.
2. Create an Account: If you don’t have one, sign up for a free account.

B. Define Your Area of Interest

1. Use the Map Interface: Zoom in on your area of interest using the map.
2. Draw a Search Area: Use the drawing tools to create a polygon, rectangle, or point.

C. Select Data Sets

1. Choose Data Sets: Click on the “Data Sets” tab.
2. Select Satellite Imagery: Choose from available datasets (e.g., Landsat, Sentinel).
3. Set Date Range: Specify the date range for the imagery you need.

D. Search for Data

1. Click the Search Button: This will retrieve the available satellite images based on your criteria.
2. Review Results: Browse through the results and look for cloud cover percentage, acquisition date, and other metadata.

E. Download Data

1. Select an Image: Click on the desired image to view details.
2. Add to Download Cart: Click the “Add to Download Cart” button.
3. Download Options: Go to your download cart and select the format (e.g., GeoTIFF).
4. Download: Click on the download link to save the data to your computer.

4. Searching for DEM Data

A. Using the USGS National Map

1. Visit the National Map: Go to USGS National Map.
2. Navigate to Your Area: Use the map interface to find your area of interest.

B. Select DEM Data

1. Open the Data Download Menu: Click on the “Data Download” option.
2. Choose DEM: Select the Digital Elevation Model option.
3. Specify the Area: Define your area of interest using the map tools.

C. Download DEM Data

1. Select the DEM Product: Choose the DEM product that meets your needs (e.g., 1/3 arc-second).
2. Download: Click the download link to save the DEM data to your computer.

5. Using Open Topography for High-Resolution DEMs

1. Visit Open Topography: Go to Open Topography.
2. Search for Data: Use the search bar to find specific regions or datasets.
3. Select a Dataset: Click on the dataset that interests you.
4. Download Options: Choose the desired format (e.g., GeoTIFF, LAS) and download the data.

6. Conclusion

This practical guide has outlined the steps to search for and download satellite and DEM data from various online sources. Familiarity with these processes will enhance your ability to access important geospatial data for your projects.