Japanese satellite series carrying several sensors, typically both multispectral and microwave.
ALOS-1 had 3 sensors
· AVNIR-2 – Advanced visible and near infrared radiometer –4-band (blue, green. Red, NIR) multispectral scanner with 10m spatial resolution and a 70 km swath
· PRISM – Panchromatic remote sensing instrument for stereo mapping - panchromatic sensor with 2.5m spatial resolution collecting either along-track tri-stereo with a 35 km swath or images with a 70 km swath. Ideal for generation of medium resolution digital elevation models.
· PalSAR – Phased Array type L-band synthetic aperture radar with several viewing geometries and modes including single, dual, and quad-polarisation
ALOS-2 - launched May 2014 - has an L-band SAR similar to PalSAR on ALOS-1 but with improved spatial resolution, observable range, and a spotlight (very high resolution) mode.
ALOS-3 will carry AVNIR-3 a multispectral scanner with improved spatial resolution and repeat coverage plus an improved PRISM sensor with 0.8m spatial resolution and a hyperspectral sensor.
ALOS-1 imagery was collected on a pre-planned and published schedule. Programming will be more feasible with ALOS-2 and -3.
ALOS-1 operated from January 2006 to April 2011; ALOS-2 was launched in May 2014; ALOS-3 is due for launch in 2015.