The Satellite Imagery FAQ - contents
Last Modified: March 11th 1997:
* Added new CINTEX access points
* Added GEOTIFF entry contributed by Mike Ruth
* Various miscellaneous updates from the backlog, including Web
references and new Jobs site.
_Your attention is drawn to the Notice and Disclaimer below. If you
haven't already done so, please read them, particularly if you are
going to use or reproduce any of the information in this document!_
This FAQ is the work of several authors, without whose valuable
contributions, suggestions and encouragement it would not have been
This FAQ deals with imagery of Earth from Space. It aims to combine
some very brief introductory material with a guide to the numerous
resources available on (and off) the Internet. It is the work of
members of the IMAGRS-L (Image Processing & Remote Sensing) LISTSERV.
We hope it will be of value to those whose work, studies or casual
interest involve Remote Sensing of the Earth.
I have also included a couple of Remote Sensing answers. The
philosophy here is simple: if it's somewhat relevant, and someone's
posted (and I've seen) a good piece, then it may get included.
This is an Internet document, and is generally updated monthly. If you
have an out-of-date version (e.g. printout, CDROM), you can get a more
up-to-date version from the addresses below.
_Call for Contributions:_ There are gaps in this FAQ. In addition,
much of the material comprises my very brief and sketchy entries to
cover what would otherwise be gaping holes! If you can fill any (or
all :-) of them, please help!
Material I can just cut-and-paste in is most likely to be useful/used.
Nick Kew email@example.com
_Note: the satfaq address is an autoresponder. If you are offering new
material or commenting on the existing contents, you should start your
subject line with keyword "submit" or "comment" respectively, which
will be filed for my attention when I do the monthly updates. All
other mails will generate automatic replies._
This FAQ has five parts, loosely classified as:
1. Contents & other meta-information (this document).
2. General Questions
3. Technical Questions
4. List of RS satellites & instruments, with pointers to information
on the Net. Note that this does not appear in the Table of
Contents, but is used as html links from elsewhere in the FAQ.
5. Further Reading (long!)
For newsgroup comp.infosystems.gis, they are merged into a single
file, to ensure the GIS-L gateway rejects it and doesn't flood readers
mailboxes (someone please tell me if this fails!!!)
Subject: Table of Contents
Subject: General Questions (2/5)
1. What are basic classes of imagery, and their sources?
o Geostationary Weather Satellites (Meteosat, GOES)
o Earth Observation Imagery
# Types of Imagery
# 3-dimensional Imagery
o Synthetic Aperture Radar (SAR)
# What is SAR
# What are the main SAR platforms?
# What distinguishes SAR from hi-res optical imagery?
# What are SAR images good for?
# What is the meaning of colour in a SAR image?
o Others (silly classification - someone suggest a better
# Radar Altimetry
(avoiding listing them until I/someone has
something to say)!
o - What about the military? _("If I knew I couldn't say;
if they told me I wouldn't believe them" :-)_
# Didn't President Clinton declassify some
2. Russian Imagery
o What about Russian Satellite Imagery?
o What are the characteristics of the KOSMOS satellite
o What are the characteristics of the RESURS satellite
o What are the characteristics of the Okean?
o What about all of the problems concerning Russian
o Can the film sources be provided in digital form?
o How can I purchase Russian Imagery?
o Are the Russian planning any future commercial satellite
3. What are the main Earth Observation Satellites and Sensors
4. Where can I get such-and-such imagery?
5. What datasets are available on CDROM
6. How do I access the imagery catalogues?
o CEOS IDN
o Cintex & clients
7. Whole-World Images
o Why create whole-world images?
o How do they create whole-world images?
o Why AVHRR? Why not, say, Landsat?
o How do they get rid of the cloud?
o Further reading
o But isn't the Great Wall of China the only manmade
feature visible from space? _Hmmm... Doesn't this
originate with moon landings, and the naked eye?_
o Why do the weather forecasters always get it wrong?
_What can I say? See an intro to chaos (I don't suppose
the fractals FAQ would be any use as a reference here?)_
* General Questions
1. What are the main National and International Remote Sensing
programmes around the world?
2. Where can I read about Government policies in Remote Sensing
3. Where can I find information on RS and the Environment?
4. Can satellite imagery be used to watch newsworthy events?
5. Jobs and Services
o Where can I advertise or look for a job in remote
o Where can I advertise or look for remote sensing and
6. Where can I get information on Geoscience Journals?
7. Software (& hardware!)
o Where can I find descriptions or reviews of software
packages? (other than the marketing hype)!
o Is there a list of Software Vendors?
o Where can I find information on Software Packages?
o What software is available in the Public Domain?
o What kit do I need to receive satellite imagery on my
8. What are the Earth Observation Standards body?
o Committee on Earth Observing Sensors (CEOS)
9. Social & legal issues
o How does copyright affect satellite images?
Subject: Technical Questions (3/5)
1. Image Basics
o What is a digital image?
o What is spatial resolution?
o What is temporal resolution?
o What is spectral resolution?
2. Image Data (previously called "Image Formats")
3. What are the different levels of imagery I can buy/download?
4. Is there a non-proprietary image format for geographic/RS
5. Do I need geocoded imagery?
o Imaging Instruments
o How do Remote Sensing Instruments Work?
o Tracking Instruments
o List of Imaging Spectrometers
o What is a Sounding Instrument?
7. Basic Processing (TBD)
8. Orbits: (TBD)
_The original idea was a mini-tutorial intro; looks like I
never got round to it :-(_
o Where can I learn about satellite orbits?
o What are the orbits of EO satellites?
o what is the advantage of a polar orbit? What can you see
from a geostationary orbit (Meteosat)? Other orbits?
o Is there a list the various satellite's orbits?
o How do I convert Landsat Path/Row to Lat/Long?
o How is satellite data received on the ground?
10. Geo-referencing (someone?)
11. I am using my images for some classification problem.
o I need to classify a mosaic of several images. How best
to do it?
o How can I assess my results?
o Is there a program to compute Kappa
o How good can I expect my results to be in practice?
Subject: Further Information (5/5)
* Further Information, tables
+ Can you point me to a good online introduction to Remote
+ I have a question that isn't covered in the FAQ. Where should
+ Related Documents and FAQs
+ Relevant Discussions on the Internet (News, Listserv, WWW)
+ WWW URL's
+ Catalogue Services
+ Terminology and Acronyms
+ Ground Stations/CEOS IDs
Outside the scope of this document, for the time being at least.
1. Phillip Ingrams "Using the Web for Geosciences" FAQ is
recommended as a starting point for exploration on the Net.
2. The USGS keeps a map of Earth and Environmental Science
resources on the net at
3. See also the WWW Virtual Library
This FAQ was started in early 1995 by Nick Kew <firstname.lastname@example.org>
who still maintains it when he can find a spare moment.
Co-author Wim Bakker <email@example.com> wrote much (most?) of the best
material, and helped a lot with compiling the FAQ. Wim continues to
contribute actively to its maintenance.
Grant Denkinson <Grant.Denkinson@nottingham.ac.uk> not only hosts the
FAQ, but frequently contributes to its maintenance.
The many authors who have contributed material, or whose posted
articles have been quoted (hopefully with their permission) are
credited alongside their contributions. Rather than try to draw a line
between major and minor contributors, here is a simple list of those
who have helped or been quoted. No doubt I've forgotten someone:
please let me know!
* Wim Bakker
* John Berry
* Peter Bolton
* Wayne Bonyck
* Grant Denkinson
* Mark Goodman
* Michael Joy
* Nick Kew
* Tom Kompare
* Ivan Krasnyj
* Chris Hermanson
* Dipak Ram Paudyal
* Guy Pierre
* Fiona Renton
* Nick Rollings
* Mike Ruth
* David Schaub
* Michael Shapiro
* W Steven Sklaris
* Chuck Wivell
Subject: NOTICE and DISCLAIMER
Copyright 1995-6 Nick Kew and co-authors
You are free to copy or distribute this document and its subdocuments
in whole or in part, provided:
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* You DO include this notice in full.
You may also include this document with a commercial product, provided
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_Disclaimer_: This is the work of individuals, not speaking for nor
endorsed by their organisations.
It is offered in good faith and in the hope that it may be of use, but
is not guaranteed to be correct, up to date or suitable for any
particular purpose. The authors accept no liability in respect of this
information or its use.
WHERE TO GET A CURRENT COPY
1. The Remote Sensing InterFAQ, under http://pobox.com/%7Esatfaq/
2. At WWW servers including:
and the WWW "faqlib":
3. Posted monthly to newsgroups including sci.answers and
4. By anonymous FTP from the rtfm archive (rtfm.mit.edu), and
get part1 (etc)
5. By email from the SATFAQ autoresponder (HTML or plain text
available). Send blank email to firstname.lastname@example.org for full details.
6. By email from the FAQserver at RTFM. Send email to
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