PROPERTIES AND TWO CHANNEL MICROWAVE MEASUREMENTS 
* 
K. Tsuchiya, S. Yamamoto and C. Ishida 
National Space Development Agency of Japan (NASDA) . 
2-4-1, Hamamatsu-cho, Minato-ku, Tokyo,105 Japan 
K. Takeda 
National Institute of Resources, STA 
2-2-1, Kasumigaseki, Chiyoda-ku, Tokyo, 100 Japan 
H. Ochiai 
Toba Merchant Marine College 
1-1, Ikegami-cho, Toba-city, Mie-ken,517 Japan 
ABSTRACT 
Two channel scanning microwave radiometer (23.8 GHz and 31.4 GHz) will be 
installed on Japanese Marine Observation Satellite (MOS)-1 scheduled for launching 
in 1986. In an attempt to find out the feasibility of snow property observation 
by this radiometer, a field experiment was conducted for 10 days in January 1982 
at the test site of Hokkaido Unversity. 
Brightness temperature was measured from a tower both in vertical and horizon- 
tal polarization. In reference with detailed in-situ information, basic character- 
istics of microwave emission from snowpack were obtained. In comparison with pre- 
decessor' results, considerably lower brightness temperature was observed which 
is considered due to dry-snow condition. Experiment results indicated that snow 
depth is measurable up to 40-60 cm. 
1. Introduction 
Marine Observation Satellite (MOS)-1 is the first Japanese earth Observation 
satellite to be launched in 1986. Two frequency microwave scanning radiometer 
(MSR) will be installed on MOS-1 with two other optical sensors. The two channels 
have frequencies centered at 23.8 GHz and 31.4 GHz. The low channel is located 
close to the water vapor absorption line at 22.2 GHz and the other channel in 
the 30GHz atmospheric window region, thereby determining the integrated amount of 
atmospheric water vapor and liquid water over ocean. These two frequencies are 
also effective in monitoring land surface such as snow and ice. In Japan, the 
nothern part of which is one of the most snowy region in the world, the application 
of microwave radiometry to remote sensing of snow has received increasing attention 
because of the microwave capability to penetrate the snow and respond to variation 
in subsurface properties under all weather condition. 
In response to the growing interest, National Space Development Agency of 
Japan (NASDA) has started cooperative study program with National Institute of 
Resources/Science and Technology Agency (STA) for investigating the measurement 
of snowpack properties by microwave radiometer. Making use of a bread board model 
(BBM) of MSR, the first field experiment was made to observe snow properties 
from a 5-meter tower. The primary objective is to observe the basic microwave 
emission characteristics from snowpack for various snow properties and meteoro- 
logical conditions. 
  
* Current affiliation Chiba University 
1-33, Yayoi-cho, Chiba-city, 260 Japan