Satellite
Photo
Bringing the finest High Resolution Satellite and
Aerial Photos for many different uses
Satellite Photo - Basic Concept
Color enhanced imagery is a method meteorologists use to aid them
with satellite interpretation. The colors enable a meteorologist to
easily and quickly see features which are of special interest to
them. Usually they look for high clouds or areas with a large amount
of water vapor.
In an infrared (IR) image cold clouds are high clouds, so the colors
typically highlight the colder regions. In a water vapor image,
white areas indicate moisture and dark areas indicate little or no
moisture, so the colors typically highlight areas with large amounts
of moisture.
Geostationary
Operational Environmental Satellites (GOES)
The
GOES system maintains a continuous data stream from
a two-GOES system in support of the National Weather
Service requirements. These satellites send weather
data and pictures that cover various sections of the
United States. Current weather satellites can
transmit visible or infrared photos, focus on a
narrow or wide area, and maneuver in space to obtain
maximum coverage. ...details
Polar
Operational Environmental Satellite (POES)
The
POES satellite system offers the advantage of daily
global coverage, with morning and afternoon orbits
that deliver global data, for improvement of weather
forecasting. The information received includes cloud
cover, storm location, temperature, and heat balance
in the earth's atmosphere. ...details
Defense
Meteorological Satellite Program (DMSP)
The
Defense Meteorological Satellite Program (DMSP) is a
Department of Defense (DoD) program run by the Air
Force Space and Missile Systems Center (SMC). The
DMSP designs, builds, launches, and maintains
satellites monitoring the meteorological,
oceanographic, and solar-terrestrial physics
environments. ...details
The
National Polar-orbiting Operational Environmental
Satellite System (NPOESS)
The
National Polar-orbiting Operational Environmental
Satellite System (NPOESS) and its managing
Integrated Program Office (IPO) were established in
1994 to converge existing Air Force, NASA & NOAA
polar-orbiting satellites into an integrated
national program. Polar-orbiters in low-Earth orbit
continue to be used to monitor global environmental
conditions, collect and disseminate data related to
weather, atmosphere, oceans, land and near-space
environment.
IR images are derived from radiation emitted from the Earth and
its atmosphere at thermal-infrared wavelengths (10-12 µm). They
provide information on the temperature of the underlying surface or
cloud.
IR images are available 24 hours per day because temperatures can
always be measured, regardless of day or night. (This is in contrast
to Visible images which are only available during the day. See
below.) The temperatures are represented either by a grey-scale
(black is no-cloud, and increasing white means higher colder
clouds), or in a colour
scheme (900Kb).
Visible (VIS) images are a record of the visible light scattered
or reflected towards the satellite from the Earth and clouds. i.e.
you can 'see' the clouds. Visible images give meteorologists extra
information that may not appear on Infrared temperature images. For
example, fog appears in Visible images, but may not in Infrared
images when the fog and the land are at the same temperature.
Visible images are only available during the daytime, because at
night the world looks black. VIS images are normally displayed in a
manner similar to that seen by the human eye. Using a black and
white colour scale, with different shades of grey indicating
different levels of reflectivity, the brightest and most reflective
surfaces are in white tones and the least reflective in black. In
general, clouds are seen as white objects against the darker
background of the earth's surface.
Water Vapour imagery is derived from radiation emitted by
water vapour at wavelengths around 6-7 µm. This is not an
atmospheric window but a part of the spectrum where water vapour
is the dominant absorbing gas. The centre of the absorbing band
is 6.7µm.
The water vapour channel is available on GOES-9, GMS, FY-2
and MTSAT.
The time stamp on the images is the start time of the
reception of the top of the image from the satellite. It takes
approximately 30 minutes for GOES-9 to complete a scan and the
image is generally available on the Web within 30 minutes of
completion, i.e an hour after the time stamp.
Time stamps
Satellite images are time stamped in "UTC"
(Coordinated Universal Time), which is equivalent to GMT or Z
time (Greenwich Mean Time). This is the start time of the
reception of the top of the image from the satellite. It takes
approximately 30 minutes for GOES-9 to complete a scan and the
image is available on the Web within 30 minutes of completion,
i.e an hour after the time stamp.
Below is a comparison of current UTC to current Eastern
Standard Time (EST), Central Standard Time (CST) and Western
Standard Time (WST) or the Daylight Saving equivalent.
To convert UTC times to local Australian times, add the time
difference between your Australian time zone and UTC. For
daylight saving add an extra hour to the difference between
Australian times and UTC. During daylight saving, the difference
for (EDT) i.e. New South Wales, Victoria and Tasmania is 11
hours instead of 10, and the difference for South Australia
(CDT) is 10.5 hours instead of 9.5.
For Eastern States, add 10 hours e.g.
0000 UTC = 1000 (10 a.m.) EST
1200 UTC = 2200 (10 p.m.) EST
1800 UTC = 0400 ( 4 a.m.) EST next day
For SA and NT, add 9.5 hours e.g.
0000 UTC = 0930 (9.30 a.m.) CST
1200 UTC = 2130 (9.30 p.m.) CST
1800 UTC = 0330 (3.30 a.m.) CST next day
For WA add 8 hours e.g.
0000 UTC = 0800 (8 a.m.) WST
1200 UTC = 2000 (8 p.m.) WST
1800 UTC = 0200 (2 a.m.) WST next day
Thermal Infrared (IR) images show the temperature of the
land, the sea or the tops of the clouds above them. Warm
temperatures (0-30° C) generally mean land or sea without
cloud cover. As the temperature decreases it implies that
clouds are getting higher and denser. Very cold temperatures
mean that cloud tops are very high, which can imply strong
convective storm activity.
IR imagery is derived from emission from the Earth and
its atmosphere at thermal-infrared wavelengths (10-12 µm)
and provides information on the temperature of the
underlying surface or cloud. However, since the emitted
radiation must traverse the Earth's atmosphere before
reaching the satellite, it is modified during passage by
atmospheric absorption and re-emission.
The conventional displaying of IR images in black and
white is to present them so they are consistant with the
appearance of visible images by having the clouds appear in
white shades against the darker background of the Earth.
Since the temperature normally decreases with height, the IR
radiation with the lowest intensity is emitted by the
highest and coldest clouds and these appear whitest. This is
convenient but is the reverse of the procedure used for VIS
images where the lowest reflectivities appear black.
Quantitative measurements of the temperature of an
emitting surface needs to take account of absorption and
emission within the window. However for qualitative
interpretation the atmosphere can normally be considered as
transparent in the window region. The only exception to this
is in the very warm, high dew point air in the tropics where
imagery of cloudless air may show patterns of grey shades
that are related to the humidity distribution.
[Source Bader
et al, 1995]
IR images are available 24 hours per day because
temperatures can always be measured, regardless of day or
night. (This is in contrast to Visible images which are only
available during the day. See above.)
The temperatures can be represented in a grey-scale
(black is no-cloud, and increasing white means higher colder
clouds), or in a colour scheme (dark-blue for land/sea and
low cloud, through various colours for mid temperatures to
very light shades for very cold high clouds). See below for
the colour scheme we use.
Colours
In colour Infrared IR satellite images only, artificial
colours have been added to indicate different temperatures.
Temperatures at the base of each colour band are:
Will DIRECWAY VoIP work with my existing DW6000 or
DW4020 system?
DIRECWAY VoIP comprises a voice appliance known as
the DW6040. The DW6040 is designed and optimized to work with the DW6000 and
the DW4020 Internet access terminals. If you have any other DIRECWAY system, speak to your
dealer about upgrade options.
back to top
Can I sign up to the service and use a PC client
instead of an analogue phone and theDW6040
to connect to my DW6000/DW4020?
No, the service is designed and optimized to work
with the DW6040 and provides constant bit rate support to ensure voice traffic is prioritized
over other data traffic. PC client software is not available and is not currently supported. back to top
Is a specific grade of service plan needed for
DIRECWAY VoIP?
All existing service plans from HNSE will support
voice over IP. back to top
Table
of Contents
We all have our favorite radio
stations that we preset into our car radios, flipping
between them as we drive to and from work, on errands
and around town. But when you travel too far away from
the source station, the signal breaks up and fades
into static. Most radio
signals can only travel about 30 or 40 miles from
their source. On long trips that find you passing
through different cities, you might have to change
radio stations every hour or so as the signals fade in
and out. And it's not much fun scanning through static
trying to find something -- anything -- to listen to.
Photo courtesy XM Satellite Radio Satellite radio broadcasters promise
crystal-clear music transmitted from thousands of miles into
space.
For more information on satellite radio and related topics, check
out the links on the next page.
Below are sample thumb-nail images of famous
places contained in the TerraServer database. Click on a thumb-nail
image to see a famous place or click on more
famous places to see a complete the complete list images of
famous sites.
Get a birds eye view of your home,
yard or street. We get you the finest High Resolution
Color Satellite and Aerial Photos for many different
uses. Satellite or Aerial photographs are available for
landowners, homeowners, travelers, vacationers, and for
professionals like architects, engineers, scientists,
geologists, appraisers, realtors and investigators. Most
photos are acquired within the last few months to a few years.
You can get an aerial view of your own street, house and yard.
You can view cars parked in someone's driveway and with
infrared* photos you can even view people inside a house or
cars parked in anyone's garage. You can get Satellite/Aerial
Photo of your state, city, town or street. Photos are
available for most locations in North America and specific
locations in 56 other countries.
High Resolution Satellite photos are available as digital
files (3000 x 2400) or on paper in the following sizes:
8" x 10", 11" x 14", 16"
x 20" and 20" x 30" as hardcopy prints.
Satellite imagery also has many commercial uses
including: * Land and water navigation * Pest control Zoning
and land use planning * Fighting forest fires * Mapping
*Investing in commodities * Tax assessment * Pollution control
*Environmental monitoring * Habitat creation and protection *
Oil and gold exploration * Organizing disaster relief *
Building roads, bridges and dams * Earthquake preparation *
Crop damage assessments * And much more. Satellite
Surveillance is becoming an essential reference for civil
engineers, farmers, city planners, insurance companies,
environmentalists, geologists, freight carriers, investigative
reporters -- and anyone concerned with the uses and abuses of
satellite technology.
SPIN-2
SPIN-2 is a joint venture with the Russian space agency,
SOVINFORMSPUTNIK. SPIN-2 imagery is film-based 2-meter
panchromatic product that is digitized and ortho-rectified.
SPIN-2 Offers 2-meter and 10-meter imagery and digital
elevation models of areas throughout the world.
ORBIMAGE
An affiliate of Orbital Sciences Corporation, ORBIMAGE is
developing a fully integrated global system of advanced
imaging satellites, U. S. and international ground stations,
and internet-based sales channels to collect, process and
distribute earth imagery products at cost levels lower than
existing or planned alternatives. ORBIMAGE provides 1-meter
panchromatic imagery.
LANDSAT, EURIMAGE, USGS and
SPOTFRANCE
UK
PERSPECTIVES
UK PERSPECTIVES is a joint venture between Simmons Aerofilms
and Nrsc, the two largest aerial mapping and survey companies
in the United Kingdom. Our objective is to jointly acquire new
aerial photography of the United Kingdom At 1:10,000 scale and
produce high quality, map accurate digital aerial imagery.
Simmons Mapping (UK) Limited and Aerofilms Limited are wholly
owned subsidiaries of Simmons Geomatics Group and together
provide total aerial & mapping solutions. Aerofilms is
believed to be the world's oldest commercial aerial
photographic company and in more recent times is better known
for producing the BBC'S Eastenders title sequence.
GEOCOMM/USGS
GIS provides USGS mapping and imagery covering the United
States. This source is the place for geographic information
systems (GIS), CAD, mapping, and location-based industry
professionals, enthusiasts, and students to gather.
AirPhotoUSA
AirPhotoUSA provides with current, true color, high resolution
aerial photography of many of the top cities in the United
States. AirPhotoUSA has assembled the largest database of
seamless, digital aerial photography in the USA.
AERO-DATA
AERO-DATA supplies with the finest black and white aerial
imagery available for most of Louisiana, with fantastic detail
in resolutions down to one foot.
Click on
the
thumbnail to
download
DW6040
System User's Guide
(PDF, 1,059K)
Click on
the
thumbnail to
download DIRECWAY
VoIP
document (PDF,
1,820K)
Click on
the
thumbnail to download
DW6040
System Configuration
Data Sheet
(PDF, 58K)
Click
here if you need
to download free Acrobat Reader®
software
These images come from satellites which remain above a fixed
point on the Earth (i.e. they are "geostationary"). The
infrared image shows the invisible infrared radiation emitted
directly by cloud tops and land or ocean surfaces. The warmer an
object is, the more intensely it emits radiation, thus allowing us
to determine its temperature. These intensities can be converted
into greyscale tones, with cooler temperatures showing as lighter
tones and warmer as darker.
Lighter areas of cloud show where the cloud tops are cooler and
therefore where weather features like fronts and shower clouds are.
The advantage of infrared images is that they can be recorded 24
hours a day. However, low cloud, having similar temperatures to the
underlying surface, are less easily discernable. Coast-lines and
lines of latitude and longitude have been added to the images and
they have been altered to northern polar stereographic projection.
The infrared images are updated every six hours with the 0000,
0600, 1200 and 1800 UTC images. It usually takes about 20 minutes
for these images to be processed and be updated on the website. The
time shown on the image is in UTC.
MapMart is a
fantastic source all kinds of data, both for the US and
worldwide. Make this your source for aerial and satellite
imagery, scanned topographic maps, and vector
street maps.
The USGS Geographic Data
Download site is the central repository for USGS 1:250K
DEMs (digital elevation model and satellite imagery), USGS
1:100K and 1:24K DLGs (Digital Line Graphic), and USGS
LULC (land use and land cover) data. Of course, all of
this data is ABSOLUTELY FREE for download.
The Earth
Resources Observation Systems (EROS) Data Center (EDC) is a
data management, systems development, and research field
center for the U.S. Geological Survey's (USGS)
National Mapping
Division. Data searching and ordering may be performed
through a variety of information management systems and
interfaces, including:
The USGS
Global Visualization Viewer (GloVis) is a quick and
easy online search and order tool for selected satellite
data. GloVis provides greater data availability,
allowing a researcher mosaic visual access to browse
satellite images from the Landsat 7 ETM+, Landsat 4/5
TM, Landsat 1-5 MSS, MRLC, and Landsat Orthorectified
data sets, as well as Aster TIR and Aster VNIR browse
satellite images from the DAAC inventory.
USGS's Earth Explorer
data discovery and access tool is the replacement
information system for the Global Land Information
System (GLIS). All of the searchable data sets found
within GLIS will be migrated to Earth Explorer this
year. The new Earth Explorer functionality includes a
secure credit card/e-commerce system and cross-inventory
search capabilities that greatly expand the data
discovery and access tools USGS can offer to it's
customers.
Photo Finder is a World
Wide Web-based, quick-search tool for locating and
ordering photographs from the USGS' National Aerial
Photography Program.
Map Finder is a World
Wide Web-based, quick-search tool for locating and
ordering 7.5-minute (1:24,000-scale) USGS maps of the
conterminous United States.
The EOS Data Gateway is
a NASA World Wide Web-based query system. This
information management system provides information on a
variety of data sets, including documentation, satellite
image browse (depending upon the data set), and ordering
services.
The Digital
Nautical Chart® is produced by the National Geospatial-Intelligence
Agency (NGA) and is an unclassified, vector-based, digital
database containing maritime significant features essential
for safe marine navigation.
The NGA Digital Nautical
Charts site offers a large selection of marine charts in DNC
format for free download. Initial data collection of the
database is from a portfolio of approximately 5,000 nautical
charts that will ultimately provide global marine navigation
between 84° North latitude and 81° South latitude and
support a variety of Geographic Information System
applications.
NOAA
National Environmental Satellite, Data and Information
Service - NESDIS operates the satellites and
manages the processing and distribution of millions of bits
of data and satellite images these satellites produce daily.
The prime customer for the satellite data is the NOAA
National Weather Service, which uses satellite data to
create forecasts for television, radio, and weather advisory
services. Click
here for the home page of NOAA
Satellites and Information (National Environmental
Satellite, Data and Information Service).
The NOAA Electronic
Navigational Charts site offers a large selection of NOAA
marine charts in S-57 format for free download. S-57 charts
can be viewed in Global Mapper v6.00 and above.
ASTER DEM data provided the first high-resolution
alternative to DTED0. ASTER DEMs are available in HDF
or Geotiff format. HDF is a self-describing format (like
SDTS or shapefiles) that very few applications recognize.
More can handle geotiff, but not the I16 or FP32 that ASTER
DEMs are offered in. As a result, it takes more work than
the casual user is willing to expend in order to use this
data. Nevertheless, it is an extremely important data set
and is expanding as more users request on-demand DEMs. See
the article. This data is available at: The NGA Raster Roam
site offers several NIMA data sets for free download,
included VMAP levels 0 and 1, DTED level 0, ONC, and TPC
data.
The MapAbility
VMAP1 Downloads page provides a simpler alternative to the
NGA Raster Roam site for obtaining VMAP level 1 data. Vector
Map (VMap) Level 0 is an updated and improved version of the
National Satellite Imagery and Mapping Agency's (NIMA)
Digital Chart of the World (DCW®). The VMap Level 1
database provides worldwide coverage of vector-based
geospatial data which can be viewed at 1:1,000,000 scale,
i.e. 1cm=10km. It consists of geographic, attribute, and
textual data stored on CD-ROM or as downloaded files. The
primary source for the database is the 1:1,000,000 scale
Operational Navigation Chart (ONC) series co-produced by the
military mapping authorities of Australia, Canada, United
Kingdom, and the United States.
The GIS Data
Depot offers a wide variety of data, including 1:24K USGS
DEM data for the US, 1:24K USGS DRGs (scanned topo maps),
and a large selection of satellite imagery and vector data
products.
The updated
National Atlas is designed to provide a reliable summary of
national-scale geographical information. Though it cannot
provide detailed map information, the Atlas directs users to
other sources for this information. Most data is available
in Shapefile, GeoTIFF, or SDTS vector format.
GeoBase Canada
provides a large assortment of FREE data for Canada,
including Landsat-7 satellite imagery, 1:50K and 1:250 CDED
elevation data, a National Road database in Shapefile
format, and the Canadian Geographic Names data set in
Shapefile format.
This NASA site
provides FREE LandSat satellite imagery for most of
the Earth's land masses circa 1990. The
GeoCover Landsat mosaics are delivered in a Universal
Transverse Mercator (UTM) / World Geodetic System 1984
(WGS84) projection.The
mosaics generally extend north-south over 5 degrees of
latitude, and span east-west for the full width of the UTM
zone.For
mosaics between 60 degrees north and 60 degrees south
latitude, the width of the mosaic is the standard UTM zone
width of 6 degrees of longitude.For mosaics above 60 degrees of latitude, the UTM
zone is widened to 12 degrees, centered on the standard UTM
meridian.To
insure overlap between adjacent UTM zones, each mosaic
extends for at least 50 kilometers to the east and west, and
1 kilometer to the north and south.
Visible (VIS) images are a record of the visible light
scattered or reflected towards the satellite from the Earth
and clouds. i.e. you can 'see' the clouds. Visible images
give meteorologists extra information that may not appear on
Infrared temperature images. For example, fog appears in
Visible images, but may not in Infrared images when the fog
and the land are at the same temperature.
The intensity of the image depends on the albedo/reflectivity
of the underlying surface or cloud. Visible images are only
available during the daytime, because at night the world
looks black. Early morning 7am VIS images show the sunlight
rising in the east, and the 7pm VIS images show the sun
setting in the west.
VIS images are normally
displayed in a manner similar to that seen by the human eye.
Using a black and white colour scale, with different shades
of grey indicating different levels of reflectivity, the
brightest and most reflective surfaces are in white tones
and the least reflective in black. In general, clouds are
seen as white objects against the darker background of the
earth's surface. The brightness also depends on the
intensity of the reflectivity and the relative positions of
the sun and satellite with respect to the earth. Shadows and
highlights can be seen where the sun shines obliquely on to
cloud. [Source Bader
et al, 1995]
Water Vapour imagery is derived from radiation emitted by
water vapour at wavelengths around 6-7 µm. This is not an
atmospheric window but a part of the spectrum where water
vapour is the dominant absorbing gas. The centre of the
absorbing band is 6.7µm.
Emissions from water vapour
low in the atmosphere will not normally escape to space. If
the upper troposhpere is moist, the radiation reaching the
satellite will mostly originate from this (cold) region and
be displayed in white shades, following the IR imagery
colour convention. Only if the upper atmosphere is dry will
will radiation originate from water vapour at warmer, mid-troposheric
levels and be displayed in darker shades on the image. In
normally moist atmosphere , most of the WV radiation
recieved by the satellite originates in the 300-600 hPa
layer, but when the air is dry some radiation may come from
layers as low as 800hPa. Because of the general poleward
decrease of water vapour content, the height of the
contributing layer gets lower towards the poles. [Source Bader
et al, 1995]
The water vapour channel is available on GOES-9, GMS,
FY-2 and MTSAT.
The time stamp on the images is the start time of the
reception of the top of the image from the satellite. It
takes approximately 30 minutes for GOES-9 to complete a scan
and the image is generally available on the Web within 30
minutes of completion, i.e an hour after the time stamp.
Sometimes an image is missed due to scheduled maintenance
outages or a systems failure. The images remain available
for 7 days.
Time Stamps
Satellite images are time stamped in "UTC"
(Coordinated Universal Time), which is equivalent to GMT or
Z time (Greenwich Mean Time). This is the start time of the
reception of the top of the image from the satellite. It
takes approximately 30 minutes for GOES-9 to complete a scan
and the image is available on the Web within 30 minutes of
completion, i.e an hour after the time stamp.
The colour
enhanced imagery web pages also have the equivalent
time in Eastern Standard Time (EST). One hour needs to be
added during daylight saving.
Below is a comparison of current UTC to current Eastern
Standard Time (EST), Central Standard Time (CST) and Western
Standard Time (WST) or the Daylight Saving equivalent.
Visible images are only available during daylight hours,
approximately EST 7am-7pm (21Z-09Z).
To convert UTC times to local Australian times, add the
time difference between your Australian time zone and UTC.
For daylight saving add an extra hour to the difference
between Australian times and UTC. During daylight saving,
the difference for (EDT) i.e. New South Wales, Victoria and
Tasmania is 11 hours instead of 10, and the difference for
South Australia (CDT) is 10.5 hours instead of 9.5.
For Eastern
States, add 10 hours e.g.
0000 UTC = 1000 (10 a.m.) EST
1200 UTC = 2200 (10 p.m.) EST
1800 UTC = 0400 ( 4 a.m.) EST next day
For SA and NT, add 9.5 hours e.g.
0000 UTC = 0930 (9.30 a.m.) CST
1200 UTC = 2130 (9.30 p.m.) CST
1800 UTC = 0330 (3.30 a.m.) CST next day
For WA add 8 hours e.g.
0000 UTC = 0800 (8 a.m.) WST
1200 UTC = 2000 (8 p.m.) WST
1800 UTC = 0200 (2 a.m.) WST next day
Aerial photography and satellite photography work in similar fashion.
Course and speed are set before entering the area to be photographed, to
ensure uniformity of speed and altitude. The result is an image of a
narrow strip, which can be combined with overlapping images of
neighboring strips to produce a panoramic view, commonly called a
mosaic. Commercially available aerial and satellite photographs are
capable of resolving objects of about 10 sq ft (1 sq m), which means
that a satellite would be able to distinguish between a car and truck.
Aerial photographs may be high oblique (including the horizon), low
oblique (below the horizon), or vertical (perpendicular to the earth).
Only the vertical may be accurately scaled for mapmaking purposes. Often
a multilens camera is used to photograph one section vertically and the
adjacent areas obliquely. The individual oblique exposures are then
corrected, scaled, and joined to the vertical section to form one
continuous photograph. By viewing two overlapping photographs through a
stereoscope, a three-dimensional image of a region, or topographic map,
can be obtained.
Images can also be produced at other wavelengths, such as microwave
or infrared, by using a technique known as remote scanning, which
measures variations in spectral reflectance rather than patterns of
light and shadow. Remote scanning aids such disparate fields as
archaeology, geology, forestry, highway construction, and land
conservation. The best-known remote scanners are the Landsat series of
satellites, which have mapped vegetation and geological formations on
the earth's surface since 1972; the French SPOT series, first launched
in 1986; Magellan, which used radar to map the planet Venus
(1990); Lunar Prospector, which mapped the moon's surface
composition and its magnetic and gravity fields (1998); Mars Global
Surveyor, which engaged in a systematic mapping of Mars (1999); and Galileo,
which returned pictures of Jupiter and its major moons (1995–2003).
"All
the Earth, all the time, live and in color": That's the pitch for a
new infotainment company called AstroVision, based in Alexandria,
Virginia, which has announced plans to place a webcam in geosynchronous
orbit 22,000 miles above Earth. Unlike weather satellites, which usually
provide one black-and-white image every 15 minutes, AstroVision (www.astrovis.com)
will deliver a live, nearly continuous, true-color, super-hi-res feed of
natural events such as volcanic eruptions, snowstorms, hurricanes,
tornadoes, and large forest fires. Night promises to yield even more
drama than day, with views of lightning borne on the tops of clouds and
multikiloton-level air bursts from meteorites burning up in the
stratosphere. "There is always something dramatic happening
somewhere on the globe," says company founder and chief technical
officer Malcolm LeCompte. "In space exploration, a pretty picture
is far more than a pretty picture. It's loaded with information."
LeCompte
started pitching his idea 10 years ago, leaving behind an academic
career at Harvard studying the atmospheric chemistry of other planets.
In July, he raised $5 million in first-round funding by convincing
investors that the same people who consistently put the Weather
Channel's Web site in Media Metrix's top 50 would also watch an Earthcam.
The satellite
itself is fairly simple, a suite of four high-definition CCD cameras -
one wide-field and three targetable narrow-field units - coupled with a
320-Mbps, 8-GHz X-band downlink that will produce one frame every four
seconds. Putting the satellite
into orbit, however, will cost about $50 million, necessitating a second
round of funding this fall.
If
all goes as planned, the first bird will be aloft by the fall of 2002,
and global coverage from a ring of five AVStar satellites will commence
by mid-2004. LeCompte hopes the effort will not only be profitable but
also increase the public's environmental awareness. "We'll be able
to see what's going on in the rain forest, both the burning and the
scars in full color," says LeCompte. "When people see the
brown earth against the green of the forest canopy, 'slash-and-burn'
will take on a whole new meaning."