Keyhole satellites are reconnaissance satellites used for military and intelligence purposes. They are designed to collect high-resolution imagery and data of the Earth's surface. Keyhole satellites are often equipped with powerful telescopes, cameras, and other sensors to capture detailed images and signals intelligence (SIGINT).

What they can spy on:

1. High-resolution imagery: Keyhole satellites can capture incredibly detailed images of the Earth's surface, allowing analysts to identify specific objects and activities on the ground. This imagery can be used for various purposes, including military operations, urban planning, disaster response, and environmental monitoring.

2. SIGINT collection: Many Keyhole satellites are also equipped with SIGINT capabilities, enabling them to intercept and collect communication signals, such as phone calls, radio transmissions, and data transfers. This information can provide valuable insights into military activities, diplomatic discussions, and other sensitive information.

3. Mapping and terrain analysis: Keyhole satellites can generate precise maps and elevation data by using various sensors, such as radar and lidar (light detection and ranging). This information is useful for military operations, navigation, and cartography.

4. Weather forecasting: Keyhole satellites can monitor weather conditions and environmental parameters, such as temperature, humidity, and cloud cover. This information can contribute to weather forecasting, climate studies, and disaster management efforts.

5. Tracking moving targets: Some Keyhole satellites are designed to track moving targets, such as ships, vehicles, and aircraft. This capability is essential for military surveillance, border security, and maritime tracking.