SAR radars for drones

Synthetic aperture radar (SAR) produces images of the ground with radar instead of light. It works day and night and through clouds, smoke, rain and dust, which makes it valuable for surveillance, maritime patrol, disaster response, and the monitoring of infrastructure and terrain.

How it works

The radar transmits pulses sideways as the aircraft flies and records the echoes. Processing combines the echoes collected along the flight path as if they came from a very long antenna, the “synthetic aperture”, which gives fine resolution from a small antenna.

Modes and features

• Stripmap and spotlight imaging: wide-area coverage or high-resolution patches.
• GMTI (ground moving target indication): detects moving vehicles.
• Maritime modes: detection of vessels in sea clutter.
• Interferometry and change detection: compare images over time to detect changes or measure ground movement.

Key specifications

• Frequency band (X, Ku, Ka, L, P…): higher bands give finer resolution and compact antennas; lower bands penetrate vegetation and soil.
• Resolution and swath width.
• Range at a given resolution and altitude.
• Onboard processing: real-time image formation versus raw data recording.
• Mass, power and antenna size, decisive on small UAVs.
• Navigation data requirements: SAR needs precise INS and GNSS for motion compensation.
• Export controls.

Manufacturers in the directory

Examples include IMSAR, Leonardo, Hensoldt and MetaSensing.