Space experiment on the International Space
Station with P-band SAR
B.Kutuza, A.Kalinkevitch, A.Zahkarov - Kotel’nikov IRE RAS, V.Stasevich, A.Zimov - NPP “ROBIS”, Yu.Smirnov - RSC “ENERGY”, Russia
Overview
Introduction and motivation
Airborne SAR experiments
Principles of building the P-band SAR on ISS
Antenna and power characteristics
Expected results
Motivation
Severe reduction of forest biomass, affecting the carbon balance
Change of sea waters movement direction (Gulf stream, Kuroshio)
Considerable reduction of water storage in Earth glaciers
Acute pollution of particular inland water reservoirs (Black Sea, Caspian Sea, Azov Sea, Baikal).
Key problems
Propagation effects in ionosphere (Ionosphere affects the phase and orientation of polarization plane of electromagnetic waves in P-band)
Design of large SAR antenna
SAR external calibration
Airborne ExperimentsLocation of the Antennas on the Plane
Main Features of the IMARC SAR Complex
Parameter Value
Frequency X L P VHF
Wavelength, cm 3.9 23 68 254
Polarization VV, HH, VH, HV
Resolution, m 4-6 8-10 10-15 15-20
Antennas: gain, dB 30 14-17
14-17 9-11
Width in azimuth, deg 18 24 24 40
Width in elevation, deg 24 24 24 60
Images Obtained by IMARC SAR System
L-band
P-band
VHF-band
Spas-Klepiki, Ryazanskaya Region
Forest Sensing
Radar and photo images of different forest cover types atX (HH-polarization), P (VV-polarization) and VHF (HH-polarization) bands
Sea Sensing
Radar images of “Chesh inlet” of the Barentz Sea and part of the sea shore obtained simultaneously at 4-cm (VV), 68-cm (VV) and 2.5 m (VV) wavebands
The images show:1) low salinity zones2) wave structures3) vortex near the Suvoy rock4) Peshy-river estuary
Location of P-band SAR antenna on the ISS.
Direction of antenna beam relative to
ISS flight direction
Antenna characteristics
Mirror antenna with 32
Antenna efficiency is 0,5
Antenna gain is 25 dB
2m
Power characteristics
Transmitted radar impulse power is 50 W
Chirp impulse duration is 25
Doppler frequency band is 2,4 kHz
Receiver noise temperature TP = 500K
s
SAR characteristics
Orbit inclination 51.7 deg
Ground range resolution is about 50 m
Observation angle
Radar swath on the ground is 40-60 km
Noise equivalent normalized radar cross-section is -30dB
0 010 35
Objects and regions
Forests and open soil regions of Buryatia, Mari El Republic, Krasnoyarsk Kray, Meshchera (Russia)
Forests of equatorial Africa and South America
Sea and sea ice of Okhotsk at various times of a year
Mountain glaciers of Caucasus, Altai, Alps, Himalayas, including those under snow cover
Water stratification in the areas of large sea currents, first of all Kuroshio and Gulfstream.
Expected results
In this space experiment we plan to work out :
Methodical questions of measurements, digital processing and interpretation of backscattered signals acquired by means of spaceborne P-band SAR
Estimation of actual level of geometric and polarization distortions arising due to the ionosphere effects
Studying the possibility of natural objects (sea, forest, ice, soil) parameters estimation
