1196
viewing the data products is done through printed QL inspec
tion. CD collection or network access. The useful tool to manip
ulate the QL data set is called Browser.
2.1 The Ionia “lkm" Quick Look product
A new Quick Lode generation algorithm has been developed in
order to:
• give a better visual impression of the image quality.
• be accurate for any NOAA satellite at any latitude and ac
quisition time (calibrated data).
• highlight land ocean atmosphere geophysical features (e.g.
cloud height, water temperature, sun glint, vegetation
strength, ice and snow).
In consultation with users, the QL product for this project has
been identified as follow: 3 colour composite of channel 1 re
flectance. channel 2 reflectance, channel 4 brightness tempera
ture in GIF format subsampled 6 km «sing the Ionia algori thm ,
(Arino and Melinotte, 1993 and Arino et al., 1993). The QL
size is based on the archived HRPT pass length, which is vari
able depending on its origin. The width is fixed to 462 pixels
and takes into account the satellite viewing angle so that each
pixel is representative of an area of 6x6 km. The maximum size
of these QL’s is around 300 kbytes.
This Quick Look extends the standard geographical and cloud
cover information to additional qualitative but also to quantita
tive information on the features that appears in the highe r level
application products (e.g. land monitoring, oceanography,
clouds statistic....).
The lKm AVHRR Quick Look
3 The Ionia “lKm” Net-Browser
Intecs has developed for ESRIN an experimental Ionia “1km"
Net-Browser. Net-Browser is a server system for publishing
Earth Observation information both in Local Area Networks
and in Wide Area Networks. The server is compatible with the
World Wide Web (WWW) 1 system, a distributed hypermedia
information system developed at CERN. In addition to the stan
dard features of a WWW server, Net-Browser offers features
especially designed for Earth Observation data as:
• simple and efficient search mechanism suitable for file-
based inventories.
• display of retrieved data together with image icons
• on-request display of previews.
• grouping of retrieval results to ease the network operations
when large number of images is retrieved.
• mechanism for displaying of the product boundaries on the
world map.
Net-Browser is accessible from any Internet site by different
window-based public domain clients like CELLO 2 cm MS-Win
dows. NCSA 3 Mosaic on MS-Windows. Apple-Macintosh and
on UNIX X Window System.
The number of hosts and users connected to Internet is con
stantly growing. More than 1.5 millions of hosts are fully con
nected to the network. There is also an exponential growth the
so called “second generation” applications for Network Infor
mation Retrieval such as Gopher, WWW and WAIS. An exam
ple of the growth of network traffic is shown on the following
table:.
Period
Gopher
WAIS
WWW
jan-92
81
366
0
nov-92
24.744
2.899
39
feb-93
60.897
4591
512
mar-93
79.024
5.416
3.W
apr-93
89.074
5.935
8.116
may-93
103.870
5.604
17.298
Network traffic in x 1.000.000 Bytes (Source: NSFNETj
The Net-Browser approach allows to broadcast recently
updated Earth-Observation information to the world-wide com
munity.
1. The World Wide Web project, carried out al the CERN, Geneva Switzerland,
is a distributed hypertext-based information system which uses HTML (Hyf* r
Text Markup Language derived from SGML) for its internal formats, and HTTT
as communication protocol.
2. Software developed at Legal Information Institute. Cornell Law School.
3. National Center for Super Computer Applications, Champaign. IL USA
3.1 A typi
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1. Universal Re
