ALOS-1 was launched on the 24th of January 2006 from the Tanegashima Space Centre in Japan and is operated by the Japan Aerospace Exploration Agency (JAXA).

ALOS-1 (also known as PALSAR) has three remote-sensing instruments which makes this satellite unique – PRISM, AVNIR-2 and PALSAR. The Japanese name for this satellite is “DAICHI”.

PRISM is a panchromatic radiometer capable of high resolution imagery to obtain terrain data including elevation. AVNIR-2 provides for better spatial resolution and is a visible, near-infrared radiometer. PALSAR is an active microwave sensor, L-band type Synthetic Aperture Radar, which allows for day or night land observation and is cloud free.

ALOS-2 (“DAICHI-2”), is a follow-on mission from ALOS-1. This satellite was launched on the 24st of May 2014 with enhanced capabilities. ALOS-2 has a spotlight mode (1 to 3m) and a high resolution mode (3m to 10m). This allows for comprehensive monitoring of disasters by providing users with more details than its predecessor.

The state-of-the-art L-band Synthetic aperture Radar aboard ALOS-2 is an active microwave radar using the 1.2 GHz frequency range, having enhanced performance as compared to PALSAR. The ALOS-2 is also capable of observing Earth during day or night and in all weather conditions.

The observation frequency of ALOS-2 will be improved by greatly expanding the observable range of the satellite by up to 3 times through an improvement in observable areas (from 870km to 2,320 km) as well as giving ALOS-2 a right and left looking function.