Conference 7.286::space

From: [email protected] (Robert J. Granvin)
Newsgroups: comp.graphics,sci.space
Subject: Re: SPOT picture wanted
Date: 23 Mar 88 14:21:45 GMT
 
    Taken from the latest issue of OMNI magazine:
 
    You can contact the U.S. Geological Survey offers a service where
you can order clear color or black and white photos of any location in
the United States.  The costs from from $6 to $65 depending on print size. 
 
    These photos can cover an area of 30 to 120 square miles, and
cover altitudes from 40,000 feet to 110 miles. 
 
    For a brochure, write:
 
	National Cartographic Information Center
	U.S. Geological Survey
	507 National Center
	Reston, VA  22092
 
    This at least is an option for someone who may not want to spend
the big bucks on SPOT images... 
  
"Cursed Eraser Causes People                Robert J. Granvin
 to Vanish Forever."                        National Information Systems, Inc.
 
[email protected]        UUCP:...uunet!{amdahl,hpda,rosevax}!bungia!sialis!rjg


From: [email protected] (Eric Sheffer)
Newsgroups: comp.graphics,sci.space
Subject: Re: SPOT picture wanted
Date: 26 Mar 88 19:35:59 GMT
Organization: The University at Albany, Computer Services Center
 
  The problem with this solution is that you have to know what you're
  getting.  SPOT provides two formats:  10 meter _panchromatic_ black
  and white or 15 meter _color-infrared_ imagery.  USGS and Earth Resource
  Obervation System (EROS) maintains a miriad of images, from Gemini, Apollo
  and Skylab orbital photographs to LANDSAT Thematic Mapper imagery.  If
  you're thinking about this option, consider National High Altitude
  Photography Program's 1:58000 scale color-infrared photographs, or
  contact a local mapping agency (transportation department, planning
  bureau, etc.) who might be able to provide larger scale imagery.  Also,
  you must be able to digitize photographs, or these sugestions are moot.
  In any event, NHAP images are available from USGS and EROS Data Center.
  
  EROS Data Center
  U.S. Geological Survey
  Sioux Falls, SD 57198
  (605)-594-6151 
_______________________________________________________________________________
                                                                  __  __
Eric Sheffer                                                      / / /  \
[email protected]                                           / / / /\ \  
Dept. of Geography and Planning                                 / /_/ / _\ \
The University at Albany          "No beach to walk on..."     /_____/ /____\ 
_______________________________________________________________________________

    Anyone know where I would go to look for a picture of my favorite
    island in the B.W.I.?  I have the lat/long pairs around somewhere
    to within a second, but it's not part of the US....  Doesn't sound
    like I'd be able to afford SPOT images.
    
    Also, what on earth or off it are "panchromatic" images?
    
    Willie

    Re: what is panchromatic?
    
    I'm not positive, but the following rings a bell...
    
    Panchromatic film (or photographs) are sensitive to all colors,
    not just "raw" brightness.  So when you get your "black and white"
    photographs, the various grey shades represent an intepretation
    of both color and luminosity.
    
    If I'm off-base here, someone please correct me (and accept my
    apologies).
    
    - dave

Re: .2 

> What is "panchromatic"? 

Referring to the Oxford English Dictionary...

	Panchromatic = Orthochromatic

	Orthochromatic

	    Representing colors in their correct relations, i.e. without 
	    exaggerating the deepness of some and the brightness of others.

As explained in .3 a panchromatic image is all colors.  A true panchromatic
image records the luminance of a scene, regardless of the color.  This is
what is usually referred to in photography as "black and white". 

Back to the dictionary...

	Monochromatic

	    Of or presenting one color only; applies specifically to light 
	    of one wavelength.

Monochromatic images are in a single spectral color.  Most color images (in 
photography, TV and most printing) are produced by combining a number of
monochromatic images, possibly with the addition of a panchromatic image. 

The infra-red false color images are similarly made of a series of 
monochromatic images made at different visible and infra-red wavelengths 
and shifted to visible colors.

jb

Perhaps more simply stated, panchromatic film is sensitive to all colors
(of human-visible light).  This means that the film records something
for any light across the visible spectrum.
In contrast, there are black and white films that do not record at one
end of the spectrum or the other.  Infrared film is just one example.
Early black and white films had this "drawback", but the plus was that the 
photographer could use a safelight of the right color during processing.
That's why you see references to red safelights and yellow-green safelights
for darkroom use.

I guess that by strick definition "panchromatic" can apply to color film too,
if there is any color film not sensitive to some colors that wouldn't be
panchromatic.

- tom]

Just to follow up, black and white photographic printing paper is
often NOT panchromatic.  Since it is used to capture only gray scale
information from a black and white negative, it doesn't need to be
panchromatic, and the matter of safelights for watching developing happen
becomes useful.

- tom]

Article: 3751
From: [email protected] (UPI)
Newsgroups: clari.tw.science,clari.local.california,clari.local.sfbay
Subject: JPL films Landers earthquake
Date: Tue, 8 Dec 92 13:25:37 PST
 
	SAN FRANCISCO (UPI) -- In a scientific first, the Jet
Propulsion Laboratory in Pasadena has released a dramatic satellite
video showing the movement of Earth's crust during last June's 7.5
Landers earthquake. 

	JPL geologist Robert Crippen told a gathering of the American
Geophysical Union that the video was taken immediately after the quake
by the French SPOT satellite orbiting 515 miles above Earth. 

	Those images were contrasted with photos taken in the same
area almost on the same day in 1991. 

	``We wanted to make sure the angle of the sun was the same so
the shadows would be the same,'' Crippen said. ``The fault rupture
caused a series of small shadows that stand out clearly from space.'' 

	Crippen said the film shows a slight clockwise rotation of
small blocks of crust. 

	The Landers quake measured 7.5 on the Richter scale and was
centered about 135 miles east of Los Angeles. 

Article: 3750
From: [email protected] (United Press International)
Newsgroups: clari.tw.science,clari.tw.environment
Subject: American Geophysical Union Briefs
Date: Tue, 8 Dec 92 12:03:20 PST
 
 _S_u_n _d_e_c_r_e_a_s_e_s _i_n
_b_r_i_g_h_t_n_e_s_s 

_J_P_L _f_i_l_m_s _L_a_n_d_e_r_s
_q_u_a_k_e 

	SAN FRANCISCO (UPI) -- In a scientific first, the Jet Propulsion
Laboratory has released a dramatic video made from satellite photos
showing the actual movement of Earth's crust during last June's 7.5
Landers earthquake.

	Robert Crippen, a JPL geologist, told a gathering of the American
Geophysical Union that the photos were taken immediately after the quake
by the French SPOT satellite orbiting 515 miles above Earth.

	Those images were contrasted with photos taken in the same area
almost on the same day in 1991.

	``We wanted to make sure the angle of the sun was the same so the
shadows would be the same,'' Crippen said. ``The fault rupture caused a
series of small shadows that stand out clearly from space.''

	Crippen said the film shows a slight clockwise rotation of small
blocks of crust, a few hundred yards across.

Article: 2710
Newsgroups: sci.space.news
From: [email protected] (Ron Baalke)
Subject:  Earthquake Filmed From Space
Sender: [email protected] (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 19 Dec 1992 07:10:13 GMT
 
From the "JPL Universe"
December 18, 1992
 
Earthquake fault motion observed in videotape produced by JPL geologist
By Mary Hardin
 
     Using satellite images taken before and after the June 28
Landers earthquake, JPL geologist Dr. Robert Crippen has produced
a video which shows the motion of the Emerson and Homestead
Valley faults in the Mojave Desert.

     "This is the first time fault motion has been observed
through the use of images acquired from space," said Crippen,
from the Tectonics and Geophysics Group, Geology and Planetology
Section 326. "The observation from space of newly fractured ground 
along fault zones is also believed to be a first," he added.

     Crippen used images from the French Satellite Pour
l'Observation de la Terre (SPOT) acquired under a data exchange
agreement between NASA and the French space agency, Centre
National d'Etudes Spatiales (CNES).

     The technique used to create the fault motion video is
similar to how weather satellite images are used to show cloud
motion on television weather reports.

     Crippen took a "before" SPOT image of the Landers quake site
that was taken on July 27, 1991, nearly a year before the
magnitude-7.5 earthquake, and he then matched that up with an
"after" image that was taken on July 25, 1992, only 27 days after
the quake.

     In order to minimize distortions, he said, it was important
to use matching images that were taken from the same orbital
position and on nearly the same day of year, to achieve the same
seasonal effects and sun angle.

     After precisely lining up enlarged portions of the images on
a computer display, Crippen flickered between the two and
observed the differing ground motions across each of the faults.
He repeated this process with other parts of the images taken of
several different sites along the faults, and in some cases, he
observed newly formed cracks in the fault zones.

     Working with JPL colleague Dr. Ronald Blom, Crippen is also
using the images as digital maps that show where the ground was
before the earthquake and where it ended up after the quake. By
using a supercomputer, the scientists hope to measure ground
motions at a level of geographic detail that has never been
achieved before, Crippen said.

     "By observing the details of fault motions we hope to better
understand the mechanisms of fault breakage and ultimately,
contribute to the understanding of the threats that earthquakes
pose to society," Crippen explained.

     Crippen presented his finding last week at the fall meeting
of the American Geophysical Union in San Francisco.

                                ###
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [email protected]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
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