337
The performance of TERS will be in line with the
existing generation of remote sensing satellites,
i.e. better than 20 m in the multispectral mode and
better than 10 m in the panchrometric mode or in a
multispectral mode with a reduced radiometric
resolution.
Data of the Japanese geostationary weatherstellite
GMS has been used to analyse the cloud cover over
Indonesia. The preliminary results indicate that TERS
can make at least one useful image from any part of
Indonesia within a two week period.
3 APPLICATIONS
In discussions with the Indonesian user community key
applications for satellite remote sensing have been
identified. The two most important in relation to the
TERS system are: the management of agricultural food
production and the management of forest resources.
Both applications were selected in view of the fact
that processes are concerned with a yearly turnover
of some billions of dollars. If the management of
these renewable resources could be improved by better
information, large benefits coud be obtained. The
frequent data, needed for proper management, cannot
be provided by existing satellite systems because of
the cloud cover problem. The two key applications
therefore can not yet become operational.
3.1 Management of agricultural food production
Any government has a need for timely information on
the supply of and need for food. This is especially
important in a country like Indonesia which is
pursuing to be autonomous in its food production.
Timely forecasts on the agricultural production are
required for the planning of import, export and
reserves of food.
Rice is the most important food crop in the
country; about 60% of the total area for food crop is
for wet land rice, and rice is the staple food,
supplying about 50% of the protein and carbohydrates
of the Indonesian food consumption. The world market
price of rice fluctuates of course, depending on the
size of the crops, but the total Indonesian rice crop
of about 30 million ton is worth billions of dollars.
About 700 million US$ of rice has been imported in
1980, against 200 million US$ in 1981. On the moment
Indonesia is producing a surplus of rice and expects
to become a supplier on the world market.
Table 1. Rice production and imports in Indonesia
*
★
Year
Production
Imports
1969
12,249
796
1970
13,140
764
1971
13,724
524
1972
13,183
1,234
1973
14,607
1,225
1974
15,276
1,137
1975
15,185
678
1976
15,845
1,506
1977
15,876
2,308
1978
17,525
1,277
1979
17,872
2,606
1980
20,163
1,196
1981
22,286
437
1982
22,837
507
1983
24,006
1,300
1984
25,825
*
(thousands of metric tons)
It is very important to have accurate and timely
forecasts on the fluctuations in the yearly food
production, because early knowledge is a valuable
asset in operating on the world market and planning
the required storage and transport.
The Indonesian food crop statistics and forecasts
are based on monthly reports on crop acreages of
local village chiefs and other relevant local
officials, while the estimation of the crop yield is
based on crop cutting of randomly selected plots.
The accuracy and especially the timelines of the
crop statistics and forecasts are questioned and need
to be improved. The application of satellite remote
sensing until now had its limitations because of the
low ground resolution of Landsat and the presence of
cloud cover. The new sensors onboard the Landsat 5
and SPOT satellites will overcome the ground
resolution limitation, however the cloud cover
problem will still seriously hamper the operational
use of these satellites for crop forecasting, as
these systems lack the flexibility to make use of the
variability in the cloud pattern. A system with a
higher revisit frequency in combination with
selective viewing can overcome the cloud problem and
will make it possible to monitor the various phases
of the crops.
In that way it will be possible to base the statis
tics and forecasts on unbiased and accurate objective
measurements and to automate the process, which will
increase the accuracy and speed even more.
The Central Bureau of Statistics, in cooperation
with other institutions, is studying the
applicability of TERS for such a crop forecasting
system.
3.2 Management of forest resources
About 60% (120 million ha) of the total land mass of
Indonesia is covered with forests. The exploitation
of forests is very important for the national
economy, as wood is the main export article after
oil. The mean annual production is over 20 million
cubic meter at a value of over one billion US$;
however the exploitation of the forests cannot
continue in this way, for on the one hand the timber
industry is progressing rapidly, requiring about 80
million cubic meter in the year 2000 and on the other
hand the national forest/ potential is declining.
The forests also have a social and protective
function besides the economic function and the forest
resource development policy is therefore aimed at:
a. Economic exploitation
b. Creation of employment opportunities
c. Conservation of the forests.
The execution of such a policy requires objective
information on the available forest resources and on
the exploitation of these resources.
The inventory of existing forests is being made and
is being regularly updated by means of field work,
aerial photography and satellite imagery. The proper
exploitation of the resources by private companies
has to be monitored by the government. Until now it
has proved to be very difficult to monitor the
operations of the concessionaires with regard to the
method and amount of logging as well as to the
compliance with the obligations for reforestation.
The inspectors in the field have an exceedingly
difficult job, because it is almost impossible to get
a good oversight over the large areas. The problem in
executing proper inspections makes it clear that
illegal logging is difficult to prevent. Illegal
logging represents a direct loss of income to the
Indonesian State.
Due to the frequent cloud cover, the use of
aircraft or existing satellite imagery however is not
effective at the moment. More frequent satellite
imagery would provide the capability to monitor the
activities of the concessionaires with respect to the
conditions of the concessions, such as:
-areas and amounts to be logged