Which satellite program is commonly used to gather imagery of the Earth's land surfaces (e.g., agriculture and geography)?

Which satellite program is commonly used to gather imagery of the Earth's land surfaces (e.g., agriculture and geography)?

• A. MODIS
• B. Sentinel
• C. WorldView
• D. Landsat

Answer: (D)

When observing how land surfaces are monitored for agriculture and geography, a program with a long, consistent record of multispectral images at a practical resolution is ideal. Landsat has been collecting Earth imagery since the 1970s, providing a stable, 30-meter view that covers the spectral bands used to assess vegetation, soil, moisture, and land-use changes. Because the data are openly available from USGS, Landsat is widely used in research and practical applications for tracking crop health, mapping fields, and analyzing geographic features over time. Other programs offer different strengths—MODIS gives daily, broad-area views at coarser resolution, Sentinel-2 provides higher-detail recent imagery, and WorldView offers very high-resolution commercial images—but Landsat’s combination of long-term data, suitable resolution, and free access makes it the most commonly used source for land-surface imagery.

When observing how land surfaces are monitored for agriculture and geography, a program with a long, consistent record of multispectral images at a practical resolution is ideal. Landsat has been collecting Earth imagery since the 1970s, providing a stable, 30-meter view that covers the spectral bands used to assess vegetation, soil, moisture, and land-use changes. Because the data are openly available from USGS, Landsat is widely used in research and practical applications for tracking crop health, mapping fields, and analyzing geographic features over time. Other programs offer different strengths—MODIS gives daily, broad-area views at coarser resolution, Sentinel-2 provides higher-detail recent imagery, and WorldView offers very high-resolution commercial images—but Landsat’s combination of long-term data, suitable resolution, and free access makes it the most commonly used source for land-surface imagery.