Present and Future of Earth Environmental Monitoring 
System in Japan 
Korehiro Maeda and Osamu Ryuguji 
Earth Observation Center(EOC), 
National Space Development agency of Japan (NASDA) 
1401 Ohashi, Hatoyama-machi,Hiki-gun,Saitama-ken 
350-03 Japan 
ABSTRACT 
Earth environment is one of the most important items for human-beings.Japan is also 
interested in earth environment problem. In order to resolve such problem, it is 
necessary to observe the whole earth from space. NASDA developed both space segment 
and ground segments for MOS-1 (Marine Observation Satellite-1) and MOS-lb. NASDA is 
also developing space and ground segments for JERS-1 (Japanese Earth Resources 
Satellite-1) in collaboration with MITI (Ministry of International Trade and 
Industry) and developing ground segment for ERS-1(European Remote Sensing 
satellite-1). NASDA is developing ADEOS (ADvanced Earth Observing Satellite) which 
has two core sensors and 6 AO sensors. Concerning domestic AO sensors, two 
equipments were proposed by the Environment Agency and one equipment was proposed by 
MITI.Concerning foreign AO sensors, two equipments were proposed by NASA and one 
equipment was proposed by CNES. TRMM (Tropical Rainfall Measuring Mission) is a 
joint project between NASA and NASDA and NASDA will develop precipitation radar in 
collaboration with CRL (Communications Research Laboratory). NASDA will participate 
in international polar platform program and develop JPOP (Japanese Polar Platform). 
In this paper,the outline of earth environmental monitoring by MOS-1 data is 
presented and the present and future earth environmental monitoring system is also 
presented. 
KEY WORDS:MOS-1,M0S-lb,JERS-1,ERS-1,ADEOS,TRMM,JPOP,Earth Environment 
1 INTRODUCTION 
Global change problem is increasingly important 
for human-beings.Earth environment can be 
monitored from space. Earth observation satellite 
is one of most important means to monitor global 
change of the earth environment. NASDA launched 
the first earth observation satellite named 
Marine Observation Satellite-1 (MOS-1) on 
Feb.19,1987 and launched MOS-lb on Feb.7,1990. 
MOS-1 and MOS-lb data are received by 11 MOS-1 
receiving stations in the world. Since there is 
no tape recorder mounted on MOS-1 .monitored area 
is limited to the area covered by these stations. 
On the other hand,future Japanese observation 
satellites will have on-board data recorders and 
some satellites will use data relay satellite. By 
these satélites, not only global data but also 
regional/local data can be obtained under the 
limitations of capacity of data recorders and 
data transmission line. In order to contribute to 
the earth environment problem, only development 
and operation of space and ground segments are 
not sufficient. For that local, regional and 
global data set should be continuously 
constructed and provided to those who is involved 
in earth environment. In this paper, present 
status of earth environment monitoring system by 
MOS-1 and future system are described and 
evaluated. 
2.PROBLEM OF EARTH ENVIRONMENTAL MONITORING 
We have many environmental problems in the world. 
Examples of such problems are deforestation, 
expansion of desert, polution of ocean, increase 
of sea surface temperature, change of marine 
current, abnormal weather, acid rain, increase of 
carbon dioxide, decrease of ozone and others. In 
order to resolve such problems, it is necessary 
to .first of all, understand the whole earth as a 
earth system and to take countermeasures. The 
former is problem of earth science and the latter 
is problem of technology, economy and politics. 
Concerning earth science, local, regional and 
global data concerning earth system should be 
gathered continously. Concerning the 
countermeasures, new technology should be 
developed and some space technology can be 
applied. 
In Japan, there are several environmental 
problems and more people are interested in these 
problems. Japanese old prime minister Mr.Uno 
stressed in Arche summit held in Paris in 
July,1989 that environmental monitoring from 
space should be promoted. Many Japanese agencies 
and universities are studying and developing for 
global environmental problems. 
Most important means for global environmental 
monitoring is earth observation satellite system 
consisting of space and ground segments. Global 
change can be monitored continously for the first 
time by using earth observation satellite. 
In order to establish earth environmental 
monitoring system, the following requirements 
should be met. 
(1) Space segment 
- To observe the whole earth continously 
- To observe various targets in the required 
precission in the required repetition 
by using combination of sensors 
- To record and process sensor data onboard 
(2) Ground segment 
- To receive, record, process and distribute 
- To develop useful data sets and distribute 
- To have access to directry of any data from 
anywhere 
To provide requested data through 
communication data network 
- To transfer sea, ground truth and other data 
via satellite