(1)verification for instrumentation and (2)verification for 
physical measurement. The former is evaluation of geometric and 
radiometric performance such as "various distortion, spatial 
resolution, signal to noise ratio (S/N), dynamic range. The 
latter is evaluation of physical measurement accuracy. These 
verification items are shown in Table 1. The MVP consists of the 
following activity. 
(1)Verification experiment 
Based upon field experiments in 1981-1983 and MOS-1 airborne 
verification experiments in 1984-1985, NASDA conducted MVP 
airborne experiments in summer,1987, in winter, 1987 and 1988, 
and NASDA will conduct airborne experiment in comming 
summer,1988. Figure 1 shows the schedule of MVP . In these 
airborne experiments, aircraft Merlin A flys over several test 
sites in Japan on MOS-1 passing days where observation 
equipments equivalent in performance to MOS-1 sensors are mounted 
and comparison between MOS-1 data, airborne data and truth data 
is made. Table 2 shows outline of MVP airborne experiments and 
Figure 2 shows test sites for MVP airborne experiments. 
(2) Routine-base verification 
MOS-1 data is evaluated routinely by using various processing 
and analyzing software installed in MOS-1 processing facility. 
(3) Overall evaluation 
Based upon test results in the labolatory obtained before the 
launch, results obtained during mission check period and results 
for compatibility test, considering the above-mentioned (1) and 
(2), overall evaluation must be made. 
2.3 Cooperative relationship 
In order to evaluate MOS-1 observation system from various 
point of view, NASDA is conducting the MVP in collaboration with 
Joint research organizations, domestic and foreign organizations 
which were selected at MOS-1 verification committee. The selected 
organizations and themes are domestic 60 organizations 73 themes 
foreign 11 countries (Belgium, Canada,France,India,Italy (ESA), 
Korea,Philippines,Singapore,Sri lanka Thailand,U.S.A) 17 organi- 
zations 22 themes, 
3. Initial results 
3.1 MESSR 
The MESSR is an electronic-scanning radiometer using CCD 
detector elements with the four bands (1)0.51-0.59pm (2)0.61-0.69 
mm (3)0.72-0.80um and (4)0.80-1.14m. Nominal spatial resolution 
is 50m. The main mission objectives of the MESSR is to observe 
land surface and sea conditions such as transparence. 
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