TOP > What is ALOS ? > Three "Eyes" of ALOS ="PRISM", "AVNIR-2", "PALSAR"
 

Three

 

PALSAR The Phased Array type L-band Synthetic Aperture Radar

PALSAR is an active microwave sensor using L-band frequency, provides higher performance than the JERS-1fs synthetic aperture radar (SAR). It enables to conduct cloud-free and day-and-night land observation. PALSAR has fine resolution in a conventional mode, plus Scan Sar mode that can extract a 250 to 350km width of SAR images at the expense of spatial resolution.
It is utilized to make DEM and to monitor designated area.


Above image is observed by PALSAR on 2006/02/15 (22:16), when ALOS is passing over HIGO waterway from south to north.

The image on the left is a birdfs eye view from Mt.Fuji to Izu Peninsula, by using land information data of Geography Survey Institute. Another enlarged image of Mt. Fuji on the right below, topography of Osawanada, western part of the summit, and other parts are clearly appears.

PALSAR is a synthetic aperture radar using microwave, so that it can observe regardless of weather or time of the day. This image is also taken during nighttime observation. Although there had been an occasional rain at that time, PALSAR successfully took a clear image.

More details of the image here

 

PALSAR Major Characteristics

Mode

Fine Scan

SAR

Polarimetric
(Experimental mode)*1

Center Frequency

1270 MHz(L-band)

Chirp Bandwidth

28MHz

14MHz

14MHz,28MHz

14MHz

Polarization

HH or VV

HH+HV or VV+VH

HH or VV

HH+HV+VH+VV

Incident angle

8 to 60 deg.

8 to 60 deg.

18 to 43 deg.

8 to 30 deg.

Range Resolution

7 to 44m

14 to 88 m

100m
(multi look)

24 to 89m

Observation Swath

40 to 70 km

40 to 70 km

250 to 350km

20 to 65km

Bit Length

5 bits

5 bits

5 bits

3 or 5bits

Data rate

240Mbps

240Mbps

120Mbps,240Mbps

240Mbps

NE sigma zero *2

< -23dB (Swath Width 70km)
< -25dB (Swath Width 60km)

< -25dB

< -29dB

S/A *2,*3

> 16dB (Swath Width 70km)
> 21dB (Swath Width 60km)

> 21dB

> 19dB

Radiometric accuracy scene

1dB / orbit: 1.5 dB

size of Antenna

azimuth :8.9m x elevation :3.1m

Note: PALSAR cannot observe the areas beyond 87.8 deg. north latitude and 75.9 deg. south latitude when the off-nadir angle is 41.5 deg.
*1 Due to power consumption, the operation time will be limited.
*2 Valid for off-nadir angle 34.3 deg. (Fine mode),
34.1 deg. (ScanSAR mode),
21.5 deg. (Polarimetric mode)
*3 S/A level may deteriorate due to engineering changes in PALSAR.

RESTEC