. FROM 
DOCUMENTS 
tion of 
tions of the 
nd vecto- . 
ours of the 
aphs. 
is are 
) contour 
25000 scale 
section) 
ology) using 
Terrain 
.ndard illu- 
.ndard D - 
¡asurements 
, of•the fi- 
iB) and (C) 
of the fil- 
>ugh classi- 
md 47 (Blue) 
:utting the 
) micrometer. 
:a when we 
/0 only (A 
surements 
a constant. 
Lth two 
abject (Ga 
jtly two 
jcorralated 
3,right 
.They are 
Lc parame - 
am of A andB) 
l a 4 bits 
of 20 bits 
s sufficient 
radar"and vi 
ons of the 
ysical 
nal aids.. 
d daily 
ield bases. 
ransmit, 
of 2 diffe 
our repre- 
through 
hods (¿PI l). 
eophysical 
airway, 
of magne- 
) can be 
.) analysis 
;ht docu- 
.ysis of 
of data(bits) 
Gbits 
y.ese measurements can be made on common airphotogra 
phs" at the scale of 1:20 000 or on the first copies 
of the LFC (see figures n° 1 and 4)»after micro-den 
sitometry with a raster of 0.004 mmm in the oerspecti* 
ve of grey spots detection without any kind of contour: 
identifications or measurements. 
Distortion-free enlargements (less than 5 micrometers 
through photagrammeiric Wild,enlargers for example) 
can also be usee. 
The figures n° 8 and 9 are actual synthetic images 
which can be extracted from MC or LFC imaery,after, 
if necessary,a microphotographical magnification. 
The contours of the Stans Airport (figure n° 4) are 
so sharp that a microdensitometry could be possible 
with a raster of 0.002 mm ©r better. 
The daily use of so important volumes of digital data 
request to use very efficient transmission networks. 
Mailings of magnetic tapes (CCT 1600 or 6250 bps) 
or magnetic disks or even laser video disks are 
unadequate solutions in most cases. 
Good results are obtained using the marine system 
Inmarsat with barge-based or ashore based stations 
when analogical documents are sufficient : the speeds 
are low (up to 4300 bauds,equivalent to 4300 bps) 
using telephone channels.The fac-simile imagery is 
goodjinside the covered areas,suitable for transmis 
sions of analogical documents (see figure n° 10). 
More frequently ,the highest data flow rates of the 
modern transmission satellites must be used from 
ground fixed stations to daily transportable receivers 
such a.s the Telecom 1 system which belong to the sta- 
controlled french company "France Cables et Radio". 
The maximal speed is 1.920 Mbauds (equivalent to 
1.920 Mbps),or 6.912 Gb per hour. 
Analogical complex documents can be transmitted by the 
same way,using analogical TV possibilities of the 
Telecom 1 system,through the use of the complete capacity 
of one transmitter with bandswidth of 36 or 25 MHz. 
The image quality of the PAL (or SECAM standard) 
analogical imagery is excellent with 625 fair lines. 
Our final conclusion is that the actual needs of the 
geophysical surveys are technically covered by the 
combined use of Metric Space imagery andjhigh flowic 
natex'transmission systems such as Telecom 1 . 
REFERENCES 
All photographs are from G.Galibert,except the figure 
n° 6 (P.I.Galibert and F.Galibert-Gautheron) and n°7 
(P.Y.Galibertj. 
Galibert, G. 1976.La mise en oeuvre de la télédétec 
tion bichromatique en montagne.Rev.Geog.Alp.2:155— 
168. 
Galibert, G. 1978.Expériences de télédétection métri 
que dans les Alpes en vue des vols Spacelab.Rev. 
Géog.Alp.1:42-63. 
Galibert, G. 1982.Nos expériences de télédétection 
analytique en Bulgarie,Hongrie,URSS et Yougoslavie 
en vue de la compression de l'information.Rech.Géog. 
16 et 17:85-91 » 
Galibert, G. 1935.Long range translocations ashore to 
offshore using Spacelab 1 Metric Camera imagery. 
Proc.DFVLR-ESA workshop 11-15 Feb.1985:81-86. 
Light, D.L. .1986.Mass storage estimates for the digi 
tal mapping era.P.E.R.S.3:419-426. 
Gbits 
4 Gbits 
255