965; Wool- 
t years, 
ing biomass 
such as u- 
estimate 
o predict 
pasture 
inted out 
76-0.78 um 
use the 
tion, and 
heric water 
eaf area 
n, and ra- 
infrared 
., the 101W 
to integ- 
.ated at 
■hich is 
> of NOAA, 
ysis(Fig.2) 
ipling fra- 
this area 
the corre- 
with the 
idel, green 
'ouse et al., 
will be 
¡en leaf 
' near inf- 
:nsity, the 
’ore, it is 
) estimate 
;hat the ND 
of view be- 
mgth effec- 
l , and if 
.s high and 
î reduced to 
984). 
Tarim River 
1 on the 29th 
me, 1985, 
of NOAA Sa- 
îllite Cen- 
ш, China, 
ЗН2+СН-1 , and 
labi«? I. Comparision of the MuAA AVIIkk and l^VNUSAl' 'iGS. Sources: 
KidwelK1981),NASA(1976) and General tlectric(undated). 
Chnractoristic 
landsat/mss* 
noaa/avhrr 
inclination of orbit 
°- 
i 
99.092° 
ileinht above surface 
916.6km 
833km. 
Number of orbits/day 
14 
14.2 
Times of coverage at equator 
09.30 
07.30 descending,. . 
, r, ->n . • J thOAA-e 
19.30 ascending 1 
02.30 descending,... . . .. 
11.30 ascending r 0AA -‘ 
orbital period 
103.3 min 
102 min 
Latitudinal coverage 
B0°N-82°S 
90°N-90°S 
Cycle duration 
18 days 
c.l day 
: round coverage 
185 km 
c.3000 km 
Field of view(FUV) 
+ 5.78° 
C£° 
+ 56 
Instantaneous field ofview 
0.086 mrad 
1.39-1.51 mrad 
(1FuV) 
Grouc* resolution(nadir) 
79m 
1.1 km 
Groijd resolution 
79.5 m along 
track 2.4km along track 
(maximum off-nadir) 
80 m across track 6.9km across track 
Samples per IFOV 
1.411 
1.362 
Number of channels 
0.5 - 0.6 
0.58 - 0.68 
0.6 - 0.7 
0.725- 1.10 
0.7 - 0.H 
3.55-3.93 
0.8 - 1.0** 
10.5 - 11.5 
(U.5-12.5*«*) 
Data precision 
6 or 7 bit 
10 bit 
♦LANDSAT-4 has a rather lower orbit(725 km) and a cycle duration 
of 16 days but overall the Mss has very similar properties to those 
.of previous LANDSATs. It also contains the 7 band, 30 m IFuV The 
matic Mapper. 
♦•This is a more accorate repres«?ntation of the spectral bandwidths 
than the value of 0.8-1.1 >im which is normally quoted. 
*** un I40AA-7 only. 
Table2. ground-collected predominately green clipped 
wet biomass. 
Plots 
Sample names* 
Coveraqe 
(%) 
wet biomass 
(kg/mu)* * 
1 
Phragmites Communis 
25 - 30 
405 
2 
Phragmites Communis + 
Alhagi Pseudoalhagi 
• 40 
936 
3 
High Phragmites Communis 
25 - 30 
585 
4 
Poacynum Hanjlersonii + 
Glycyrrhiza Uralensis + 
Lycium Kuthenicum 
90 
1305 
5 
High Phragmites Communis 
50 - 60 
1305 
6 
Calamagrostio Hpigejps 
70 - 80 
765 
7 
Phragmites Communis 
10 
315 
6 
Phragmites Communis + 
Kereiinia caspica + 
Kalidium caspicum + 
Alhagi Pseudoalhagi 
40 
169 
9 
Short Phragmites Communis 
20 - 25 
270 
10 
Phragmites Communis 
30 - 35 
400 
11 
High Phragmites Communis 
40 
1080 
*in Latin. 
**One Chinese mu = 0.0667 ha. 
through the HP1000 image processing system 
in this center, a map(Fig.3) of the ND dis 
tribution has been portryed. It is clearly 
illustrated that the high ND value is along 
both sides of the Tarim River, while the lo 
ver ND value is in the south area where the 
desert is occupied. 
To compare the ND value with green leaf 
biomass, 11 sampling locations with 1 m 2 
area plot were operated, for each plot wet 
grass matter by hand clipping was weighed, 
and meanwhile, the ND value was calculated. 
Pi# 2 The relationship between ND with the 
field spectral radiator and wet 
biomass in the test area. 
Fig.3 The Normolized Difference for the Ta 
rim River Basin in Xinjiang from NOAA AVHRR 
on 13th of June, 1983. 
WET BIOMASS (.kg/mu) 
Fig.4. The relationship between Nd from NOAA 
data and wet biomass in the test area. 
Than, a correlation analysis is shown in Fi~ 
g.4. The sketch explain that the relation 
ship between ND and green leaf biomass is 
very available, and the correlation coeffi 
cient arises to that of r = 0.95, According