The document discusses the acquisition of information about terrain from satellite imagery in order to produce digital terrain models. It describes how satellite imagery can be used to measure elevations across landscapes and generate high-resolution topographic data. This data capture allows for the production of detailed three-dimensional models of the terrain being imaged.

1. 0
1
2
1
0
3
4
6
7
8
3
6 9
8
1
1
1
1 6
1
6
!
!
!
!
! !
#
!
#
!
#
!
#
!
# !
$
%
!
$
%
!
$
%
!
$
%
!
$
%
'
(
)
*
(
+
,
-
.
,
/
8
,
4
/
.
4
0 14
0 2 4
1 34
2
4
4
2
4
1
,
,
4
9
254
9
2 4
0 62 4
29
0
,
7
.
4
8
,
,
8
/
(
9:;=
:
?@
A
@
=
@
B
C
D
E
@
F
E
GH
;B
F
A
I
@
C
;B
J
HD
B
HC
E
;@
;K
LA
@
F
E
GHK
MA
B
F
B
HF
E
@
N
J
LMO
'
,
,
,
P
/
.
4
/
Q
4
R
.
,
(
,
/
Q
S
.
(
T
/
.
U
,
/
4
,
/
(
/
.
,
S
9V
,
/
.
(
R
.
,
.
/
/
Q
/
(
(
W
,
.
X
1
W
4
/
.
(
(
/
(
/
/
(
W
/
'
,
T
,
,
/
,
/
/
Q
,
.
S
,
,
,
,
Y
0
4
2
4
6
Z
4
3
Z
4
2
Z
4
7
2
4
6
Z
Z
4
0
Z
Z
4
2
Z
Z
4
6
Z
Z
Z
P
[
4
.
,
/
Y
6
0
,
[
4
,
(
.
.
,
R
.
,
,
,
/
Q
/
.
,
S
9V
Q
,
/
4
]
/
/
/
/
(
W
/
.
.
,
R
.
,
,
,
/
,
/
S
4
/
,
(
P
,
(
Q
/
'
(
(
,
(
R
.
(
Q
/
4
(
.
,
.
/
,
,
/
(
.
(
U
/
/
(
/
/
Q
4
.
^B
_E
GH`
ab '
8
c
6
6
Z
6
'
8
2
0
d
0
eB
=
B
F
F
E
:H@
A
B
C
F
B
H@
A
E
:
F
=
E
f
D
E
F
:`
J
HD
B
HC
E
;@
;B
C
;B
?A
B
F
E
?E
D
@
F
E
GHg
?@
A
@
;E
h
B
A
B
HD
B
C
;A
@
F
E
:HB
C
i
?B
A
E
:;:C
;B
A
B
D
:A
H:
LA
@
F
E
GH j^k j^l j^b
! j^m
! j^l
! j^$
l j^b
!
! j^k
!
! j^l
!
! j^b
!
!
!
6
, $
b
Y
2
2
n
7
[
b
b
#
Y
c
2
6
d
3
[
b
o
m
Y
6
6
n
0
0
[
k
p
l
Y
0
Z
6
2
0
[
m
$
b
Y
0
2
7
d
Z
[
#
l
o
Y
3
6
3
7
d
6
[
l
k
p
Y
3
d
Z
c
n
7
[
$
l
m
Y
2
Z
0
6
3
3
6
[
b
k
!
#
Y
7
c
Z
0
0
[
b
$
b
$
Y
6
Z
n
Z
3
3
3
Z
[
0
, #
o
Y
3
2
d
3
[
$
#
Y
2
2
6
Z
d
[
b
!
o
Y
7
7
6
2
7
[
b
p
l
Y
6
3
6
0
n
3
[
k
#
!
Y
6
d
7
3
n
0
[
k
q
o
Y
0
Z
3
n
[
m
#
m
Y
0
3
3
2
c
0
[
#
p
q
Y
3
0
d
c
d
[
$
p
b
Y
2
Z
d
6
2
d
[
b
b
b
#
Y
7
Z
7
0
6
d
6
[
3
, m
o
Y
0
c
n
[
l
$
Y
3
c
0
[
p
k
Y
d
Z
6
0
0
[
b
#
#
Y
6
Z
6
0
0
c
[
b
p
$
Y
6
3
Z
3
Z
[
k
m
!
Y
6
2
c
3
c
[
k
o
o
Y
6
c
6
2
0
[
m
p
!
Y
0
2
3
d
7
6
[
o
!
$
Y
3
n
3
6
6
3
Z
[
p
o
l
Y
2
n
6
d
7
c
[
, m
!
Y
0
3
6
[
#
p
Y
3
d
d
n
[
o
p
Y
2
Z
6
Z
0
[
b
k
!
Y
c
2
6
n
Z
[
b
l
o
Y
6
Z
c
0
2
[
b
q
k
Y
6
3
0
3
0
6
[
k
k
k
Y
6
2
6
3
7
c
[
m
b
$
Y
0
6
6
2
d
Z
[
l
!
$
Y
3
0
n
n
2
[
$
k
m
Y
2
n
6
Z
0
[
2
, k
o
Y
0
Z
3
2
[
#
k
Y
3
6
d
Z
[
o
!
Y
3
c
c
[
b
!
#
Y
7
6
d
2
[
b
m
o
Y
n
0
0
6
[
b
o
$
Y
6
6
2
0
7
n
[
b
q
#
Y
6
3
0
3
0
n
[
k
$
o
Y
6
c
c
c
[
#
#
b
Y
0
c
d
c
0
0
[
o
k
q
Y
3
n
n
6
0
0
Z
[
d
, k
m
Y
6
c
3
0
[
m
$
Y
0
c
2
3
[
l
m
Y
3
n
7
n
[
q
m
Y
d
d
6
c
[
b
k
b
Y
c
6
n
c
[
b
#
q
Y
6
Z
0
0
n
[
b
$
m
Y
6
6
c
0
n
3
[
k
#
o
Y
6
d
3
2
[
m
q
#
Y
0
2
2
7
3
3
[
l
o
b
Y
3
2
d
6
Z
c
n
[
7
, k
b
Y
6
d
0
n
[
m
#
Y
0
2
c
[
#
p
Y
3
2
7
0
[
p
l
Y
d
Z
6
3
[
b
b
!
Y
7
d
6
7
n
[
b
m
l
Y
n
3
0
0
d
[
b
l
$
Y
6
Z
7
0
d
d
[
k
k
#
Y
6
n
3
n
2
[
m
l
$
Y
0
3
0
d
d
d
[
l
b
!
Y
3
0
n
c
n
[
c
, b
q
Y
6
2
0
d
[
m
b
Y
0
3
[
#
#
Y
3
0
d
d
[
$
p
Y
2
2
6
0
3
[
b
!
b
Y
7
Z
6
d
2
[
b
k
l
Y
c
d
0
Z
c
[
b
#
#
Y
n
c
0
2
[
k
!
o
Y
6
3
7
3
d
[
m
k
q
Y
0
6
3
d
6
3
[
#
o
q
Y
0
n
c
n
6
Z
[
n
, b
p
Y
6
0
2
[
k
q
Y
0
0
6
[
#
b
Y
3
Z
d
6
[
$
k
Y
2
6
6
6
2
[
q
#
Y
d
2
6
2
3
[
b
b
o
Y
7
n
6
n
3
[
b
m
#
Y
n
6
0
0
c
[
b
q
b
Y
6
0
7
3
3
c
[
m
!
o
Y
6
n
c
2
d
n
[
#
m
o
Y
0
7
7
c
2
[
6
Z
, b
$
Y
6
3
0
3
[
k
$
Y
0
Z
3
n
[
m
q
Y
0
c
2
7
[
o
p
Y
c
6
Z
7
[
p
p
Y
d
6
6
[
b
!
p
Y
7
6
c
6
[
b
k
o
Y
c
2
0
6
3
[
b
$
q
Y
6
6
n
3
6
d
[
k
p
o
Y
6
c
2
2
3
3
[
#
!
p
Y
0
2
n
7
n
6
[
6
6
, b
o
Y
6
0
0
0
[
k
o
Y
6
n
3
d
[
m
o
Y
0
7
2
[
o
#
Y
2
6
Z
6
[
p
m
Y
2
c
6
3
2
[
b
!
k
Y
7
Z
6
7
Z
[
b
b
p
Y
c
6
0
Z
6
[
b
o
q
Y
6
6
0
0
n
c
[
k
$
!
Y
6
7
2
2
Z
0
[
m
p
#
Y
0
7
d
[
6
0
, b
l
Y
6
0
0
Z
[
k
#
Y
6
c
3
2
[
m
#
Y
0
2
2
6
[
o
b
Y
3
n
d
[
$
q
Y
2
2
6
0
c
[
q
$
Y
d
d
6
d
6
[
b
b
k
Y
7
d
6
n
Z
[
b
o
!
Y
6
Z
d
0
c
0
[
k
l
l
Y
6
d
d
7
d
[
m
o
#
Y
0
3
6
7
Z
d
[
6
3
, b
#
Y
6
6
6
n
[
k
m
Y
6
7
3
3
[
m
m
Y
0
n
[
l
p
Y
6
n
6
[
$
l
Y
2
0
6
0
0
[
q
k
Y
d
3
6
2
[
b
!
$
Y
7
3
6
c
6
[
b
l
k
Y
6
Z
6
0
d
n
[
k
#
m
Y
6
2
7
2
3
[
m
#
o
Y
0
0
Z
d
7
0
[
6
, b
#
Y
6
6
6
n
[
k
k
Y
6
d
3
6
[
m
b
Y
0
3
7
[
l
l
Y
3
n
c
7
[
$
b
Y
2
Z
6
6
d
[
p
p
Y
d
Z
6
7
[
b
!
k
Y
d
n
6
7
3
[
b
#
l
Y
n
7
0
2
d
[
k
m
k
Y
6
2
Z
3
0
[
m
m
b
Y
0
6
Z
d
6
[
6
2
, b
m
Y
6
Z
6
c
[
k
b
Y
6
d
3
Z
[
m
!
Y
0
0
2
[
l
m
Y
3
7
c
3
[
o
p
Y
c
6
6
0
[
p
#
Y
2
c
6
Z
[
q
$
Y
d
d
6
d
2
[
b
m
q
Y
n
3
0
d
[
k
k
k
Y
6
6
[
m
b
$
Y
0
Z
6
d
6
[
6
d
, b
m
Y
6
Z
6
7
[
k
!
Y
6
2
0
n
[
k
q
Y
0
6
3
[
l
b
Y
3
d
c
Z
[
o
o
Y
d
6
Z
7
[
p
b
Y
2
2
6
3
2
[
q
#
Y
d
6
2
n
[
b
m
m
Y
c
n
0
3
d
[
k
b
m
Y
6
3
c
3
n
c
[
m
!
#
Y
6
n
3
2
n
Z
[
6
7
, b
k
Y
Z
n
6
d
[
b
q
Y
6
0
c
[
k
p
Y
0
Z
6
[
#
q
Y
3
7
7
[
o
m
Y
6
Z
3
[
$
p
Y
2
3
6
3
Z
[
q
!
Y
d
6
6
2
3
[
b
k
q
Y
c
d
0
0
7
[
k
!
l
Y
6
3
3
3
c
3
[
k
q
m
Y
6
c
d
2
d
c
[
6
c
, b
k
Y
Z
n
6
d
[
b
q
Y
6
0
7
[
k
$
Y
0
Z
Z
[
#
$
Y
3
3
7
[
o
b
Y
0
6
Z
Z
[
$
l
Y
2
0
6
0
2
[
p
$
Y
2
n
6
c
[
b
k
#
Y
c
3
0
6
n
[
b
q
p
Y
6
0
n
3
d
n
[
k
p
m
Y
6
7
n
2
c
[
6
n
, b
b
Y
Z
n
6
2
[
b
p
Y
6
0
d
[
k
o
Y
6
n
3
c
[
#
l
Y
3
0
7
0
[
l
q
Y
6
n
d
[
$
m
Y
2
Z
6
0
6
[
p
#
Y
2
7
6
3
[
b
k
!
Y
c
Z
0
6
0
[
b
q
k
Y
6
0
3
2
7
[
k
$
m
Y
6
7
2
3
Z
[
0
Z
, b
b
Y
Z
c
6
2
[
b
p
Y
6
3
0
2
[
k
l
Y
6
c
3
7
[
#
#
Y
3
6
7
Z
[
l
$
Y
Z
n
3
[
$
!
Y
c
6
6
7
[
p
b
Y
2
2
6
3
c
[
b
b
o
Y
7
7
0
Z
2
[
b
p
o
Y
6
0
Z
3
d
[
k
o
l
Y
6
d
c
2
6
3
[
0
6
, b
b
Y
Z
c
6
[
b
$
Y
6
3
0
[
k
#
Y
6
c
3
d
[
#
m
Y
3
Z
d
c
[
l
l
Y
3
n
n
Z
[
o
p
Y
7
6
6
[
$
q
Y
2
6
3
[
b
b
m
Y
7
2
6
n
n
[
b
p
!
Y
6
6
7
3
3
d
[
k
l
$
Y
6
d
3
n
c
[
0
0
, b
!
Y
Z
c
6
[
b
$
Y
6
0
0
[
k
#
Y
6
7
3
2
[
#
b
Y
0
n
d
d
[
l
#
Y
3
7
c
c
[
o
o
Y
2
6
6
6
[
$
$
Y
2
0
6
3
Z
[
b
!
q
Y
7
3
6
n
3
[
b
$
l
Y
6
6
3
3
0
d
[
k
#
q
Y
6
2
c
c
[
0
3
, b
!
Y
Z
c
6
[
b
o
Y
6
0
0
3
[
k
m
Y
6
7
3
[
#
!
Y
0
c
d
[
l
k
Y
3
d
c
2
[
o
#
Y
6
Z
c
[
$
l
Y
2
6
6
0
7
[
b
!
o
Y
7
6
6
c
c
[
b
$
!
Y
6
6
Z
3
6
7
[
k
#
m
Y
6
2
7
6
[
0
, b
!
Y
Z
c
6
3
[
b
o
Y
6
0
0
0
[
k
k
Y
6
d
3
3
[
m
q
Y
0
c
d
0
[
l
b
Y
3
2
c
3
[
o
m
Y
3
6
Z
2
[
$
m
Y
n
6
0
3
[
b
!
#
Y
d
n
6
c
3
[
b
o
o
Y
6
Z
7
3
Z
n
[
k
m
o
Y
6
2
Z
2
c
[
/
,
r
Q
,
/