EROS Data Center Earth Resources Technology Satellite (ERTS)

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A 1973 video from the EROS History Project on the value of the Earth Resources Technology Satellite (ERTS), which was later renamed Landsat. 


Date Taken:

Length: 00:27:32

Location Taken: Sioux Falls, SD, US


Kind: captions
Language: en


Thrusting outward into space,
we gain new perspective on ourselves.

How beautiful it is, our
cloud-wreathed spaceship, planet Earth.

How beautiful and how small.

The view from space shows us,
as never before, the strict limits for

accommodating man’s growing
numbers and his expanding technology.


The Earth, seen whole,
is a compelling reminder

of the need to safeguard our Earthly
resources – soil and the land.

Food and fiber.

The forests.

The rivers.

The lakes.

The seas.

The oceans.

[explosion sounds]

Non-renewable treasure.

We are ever more aware
that man’s future on Earth

depends on how well he
conserves his Earthly heritage.

We need better ways to
inventory and monitor our resources

and to learn
more about them.

Photography from an
orbiting satellite can provide

the information we need
at a cost we can afford.

The Gemini and Apollo programs
provided the first Earth images

useful in studying
the planet’s resources.

These experiments have led to
the development of an unmanned

satellite system for surveying
Earth resources from space.

The Western Test Range in
California, July 23rd, 1972.


Perhaps no new development in
space is more significant than this.

ERTS – short for Earth Resources
Technology Satellite.


ERTS 1 – the first experimental ERTS
satellite, circling the Earth pole to pole.

Its job – to send back images
of the Earth’s surface about which

we need more information,
images obtained most readily,

or in their most useful form,
by remote sensing from outer space.

Seen from far out,
the forests and fields

reveal the spread of disease
and insect infestation.

A spacecraft can provide geologists with
clues to where to search for oil or metals.

Space imagery can give us new
knowledge of living marine resources.

It offers an ideal means
to monitor change.

An ocean chewing away
at the edge of a continent.

A desert’s advance.

A volcano’s fury.

A glacier’s creep.

The dynamics of land use and
the growth and decay of cities.

We can map the
world from space,

and we can update the
maps as the world changes.

There is no end to the variety of
ways space imagery may help us.

Pioneer work in interpreting images
obtained by remote sensing was carried

out at the University of
California at Berkeley.

A leader among the pioneers,
Professor Robert Colwell.

- For approximately 50 years, man has
been taking inventory of various Earth

resources, such as timber, forage, soils,
water, mineral, and agricultural crops

through the use of conventional
black-and-white aerial photographs that

have been taken from an altitude of 3 to
4 miles above the surface of the Earth.

One such photograph is shown in this
view of our NASA San Pablo Reservoir

test site only a short distance from
the Berkeley campus of the

University of California, in which
our work is headquartered.

You will notice in this view that we
can readily discern differences

in muddiness of the
water in these two reservoirs.

We can see grassland differentiated
from timberland and brushland,

and even among the tree species
to tell hardwoods from conifers

and something of
the volume of each.

Within the past few years, NASA has
provided us with imagery taken from an

altitude of 14 miles instead of 3 or 4.
On this photography, it is possible to see

essentially the same resource features as
on the larger-scale photos, and we cover

a tremendously increased area
because of the higher altitude.

- Now, NASA has made the great
leap from 14 miles to outer space.

ERTS is a flying observatory,
orbiting the Earth about 500 miles up.

It carries two independent
image sensors.

One is a camera system –
essentially three cameras in one.

Each camera is sensitive to
a different color band

in the electromagnetic
energy spectrum.

The three cameras simultaneously
photograph the same area 100 nautical

miles square. They take overlapping
pictures as the spacecraft travels.

The other sensor, sensitive to four
spectral bands, is a line-scanning device.

Its optical system scans across
the same 100-mile-wide path.

If a ground station is in sight,
the spacecraft transmits the data from

the sensors immediately. Otherwise,
stores it on tape for transmission later.

The satellite’s orbit, near-polar
and circular, takes 103 minutes.

Due to the Earth’s rotation,
each new orbit is displaced

about 1,500 miles to
the west at the equator.

The spacecraft makes three
passes over North America daily,

14 around the globe.

Each new days’ path overlaps a
part of the previous day’s track.

Thus, the Earth is progressively viewed
at the same local time daily and is

completely covered every 18 days,
except for small areas near the two poles.

At Goddard Space Flight Center
at Greenbelt, Maryland, the operations

control center monitors the spacecraft’s
flight night and day, watching every

element of its operation and issuing
orders that control its performance.

Each time the spacecraft comes over
the arctic horizon, it sends its stored data

to the nearest of three ground stations,
which records it on tape.

It continues to send data to the
nearest ground station in sight.

All tapes produced at the Alaska
and California stations are shipped

by fast mail to the station
at Goddard for processing.

At the Goddard facility,
the data is first annotated

as to what each image is
and when it was taken.

The annotated data is
converted to a film negative.

The film is taken to the
photo lab and developed.

The spectral band images
are printed in black and white.

They may also be combined
to form color pictures

using contrasting colors
to aid interpretation.

The data is also transferred
to tapes that can be processed

by conventional computers.
From the Goddard facility, a daily

stream of images and tapes, shipped to
more than 300 principal investigators,

over 100 of whom are in some 35
countries throughout the world.

These investigators are using the data
obtained from ERTS to study numerous

problems involving both
the natural and social sciences.

- This is a satellite photo taken
by ERTS 1 from an altitude

of more than 500 miles. The entire
area shown on this high-altitude

aerial photo is encompassed in this
small area of the satellite photograph.

A view taken from our same
vantage point, looking this

seemingly short distance
to Mount Diablo,

shows that it is a tremendous
distance away, nevertheless.

In this area, we see the present boundary
of the floodwaters from a recent flood.

And by monitoring this every 18 days
with photographs from ERTS,

we are able to monitor the rate
at which the floodwaters recede.

In this way, we can relate the
mortality of fruit trees and other crops

to the length of time
they are inundated,

which is of value in predicting
damage to crops in future floods.

Finally, if we look in this same
view to the agricultural crops

in the Sacramento
San Joaquin Valley,

we see one type of crop in this area –
vineyards associated with sandy soils.

An entirely different crop in this area –
sugar beets and asparagus in

the peat and muck soils.
Still a third crop in the heavy clay soils,

in this case, rice, recognizable
by its very dark tone.

And other crops associated with
soil types throughout the area.


- ERTS imagery, where a single,
small picture covers a vast area,

puts a new premium on
interpretive technique.

The color additive viewer is all but
indispensable for many investigators.

Among them, NASA’s senior
geologist, Dr. Nicholas Short.

- The color additive viewer is an
instrument that uses color filters to

enhance certain features of an image
we’re particularly interested in.

For instance, here’s a
black-and-white picture

of the Monterey Bay
area in California,

produced by the infrared channel
on the ERTS multispectral scanner.

Well, if we project this image through
a green filter, the lighter gray tones,

which are vegetation,
such as the farm areas

and the Great Valley,
will show up more green.

By combining different spectral images
and trying different filters, we can get a

wide variety of effects and choose the
one that’s best suited to our needs.

The investigator uses his ability to
associate small color differences in the

renditions we’ve just seen with ground
features to get the desired information.

- Imagery may also be analyzed
by isolating individual elements.

This is called
thematic mapping.

In this ERTS image,
for example,

the open water areas have been
extracted and printed separately.

Also, the ice
and snow areas.

The U.S. Geological Survey has
made thematic mapping a fine art.

With the help of a computer
and highly specialized equipment,

information is produced
that enables an operator

to write precise instructions
to the photo laboratory.

When these instructions are followed,
a single image may be sub-divided

into as many as 20 different foils.

One showing only water.

One for ice and snow.

Others showing forest.

Open fields, crops, bare soil,
massed works of man, and so on.


Laramie, Wyoming.


For scientists at the University of
Wyoming, an ERTS-sized assignment.

The state itself – Wyoming
and its natural resources.

- The Wyoming project is
multidisciplinary and includes such

areas as botany, geology, zoology,
plant science, and physics.

Looks as though Wyoming will supply
energy for a good part of the country,

and we hope we can
do it without pollution.

We hope, through the use of ERTS …
- Professor Robert Houston,

head of the geology
department at the state university.

- … the study of the natural
resources of the state of Wyoming.

And we think, in integrating all of
these programs, the ERTS, the U-2,

and the multi-level viewing with
low-level aircraft, we will have

a very suitable program for
studying our natural resources.

- On the day of the ERTS flyover,
ground conditions are tested.

At the same time that the satellite swings
toward Wyoming 500 miles up, a NASA

C-130 prepares to make its imagery run
over the same terrain at 20,000 feet.

The aircraft carries more sensors
than the satellite, and its images

will be rich in detail, but it
will not get the big picture.

It will not return periodically,
will not monitor.

Plane and satellite
complement each other.

- Wind, 40, westerly.
- 40 westerly. Got it.

- Humidity, 40.
- Okay.

- Temperature, 68.
- 68. Check.

- Solar radiation is reading.
- Good.

- For the scientists who are evaluating
ERTS, the multi-level approach, using

ground information, aircraft information,
and space information, is invaluable.

- Ron, let’s see if we can identify
some of these faults you found

on the aircraft imagery on ERTS.
- All right, Bob.

On the aircraft image, we’ve got
about 3 miles of a fault here.

If we look at this on the ERTS image,
we can extend it to about 60 miles.

The more exciting is one down here on
the ERTS image – a very major structure.

Cuts across the
whole mountain range.

We’ve never known about it
before until we had the ERTS image.

I wonder if we extended
that into the basin.

If we could, it might be useful
in petroleum exploration.

Possible. Possible.

So this makes a target out in the
field to go look at it on the ground.

- The rugged Wyoming terrain, yielding
up secrets of her natural resources.

But ERTS does not just help us
to know nature’s work better.

Man’s work as well.

At Dartmouth College,
Professors Robert Simpson and

David Lindgren are putting ERTS
to work in regional planning.

- We here at Dartmouth are
concerned about a pressing social

and economic problem –
urban sprawl.

And conversely, with a
disappearing resource – open land.

- Our general area of interest is
that highly urbanized section

of the eastern seaboard which extends
from Boston southward to Washington,

and to which has been
given the name Megalopolis.

Our specific area of interest
is the New England section of it.

- Increasingly, the spreading problems
of Megalopolis require a broader-based

treatment than that of
individual metropolitan areas.

This is an ERTS photograph of
southeastern New England.

Long Island Sound, the Atlantic Ocean,
the face of Cape Cod, and Boston.

By enlarging this area,
which corresponds to

the state of Rhode Island, we can
make a land use map of that area.

- There it is, along 44 – the commercial
ribbon of development that we’re

going to have to throw in
with the industrial category.

- That’s right.
We find that on the ERTS imagery,

we can recognize at least
eight different land use categories,

each represented on the
completed map by a different color.

- So red represents a combination

The orange, multi-family housing.

The yellow, single-family housing.

We’ve used green to represent
woodland, blue for water,

black for transportation,
and brown for agricultural.

Vacant areas are
clouds on the photograph.

The next step is to tabulate information
from the map and input it to a computer.

- One commercial.
One single residential.

Now multi, multi, two clouds.
- The immediate response available

with the Dartmouth time-sharing
system makes the database

not only a display vehicle, but an
invaluable research tool as well.

We’ve learned enough now
to know that ERTS is a valid land use

study tool for regional planning.
- Yes, this gives us a new capability.

We can monitor change,
and we can keep track of growth,

and we can tell whether
that growth is, in many cases,

a healthy form of growth
or an unhealthy one.


- The flow of ERTS images
is but the onset of a vast volume

of space imagery to come.
So vast that, to study it,

we shall need all the aid
from technology we can get.

At Purdue University, at the Laboratory
for Applications of Remote Sensing,

they are pioneering in the use of
the computer to analyze images.

Professor David Landgrebe and
his associates start with a

computer-compatible tape
that contains the imagery data,

and the computer
processes the image.

In order to give the computer the
information it needs to make its analysis,

the investigators must know what’s
in the area covered by the image.

They get this ground truth,
as it is called, by making

on-the-spot checks of
what actually is there.

Spectral readings taken
close up support the research.

Training the computer, the investigator
identifies specific shades of gray as, say,

corn, soybeans, water, and so on.
Once the computer knows these

spectral signatures, it can identify what
they represent anywhere in the image.

And it can print out its finding in
whatever form the investigator requests.


At the Earth Satellite Corporation,
a privately owned company, Dr. Robin

Welch and his associates use low-flying
aircraft to speed up ground truth studies.

In a typical
agricultural investigation,

the farm fields are plotted
from an ERTS image.

- We can get it tomorrow
if the weather clears.

But we want to get these agricultural
crops before they change much.

And what we’re going to do
is get the crop types plotted

on this map, as Steve and I fly it,
and then we’ll give those to you.

[airplane sounds]

- Field by field, pilot and observer
collaborate on the identity of each crop,

doing in a few hours what
would take days by car and on foot.

- Of course, we’ve got the coordinate
locations so that your computer people

will be able to just take that and enter
right off the chart to train the computer

as to what these agricultural types are.
And I think they’re accurate.


- But there are other parts of the world
where ground truth is not yet accessible,

where remote sensing
plays a special role.

One who knows this well is
Mr. George Gryc, chief of the

branch of Alaskan geology,
U.S. Geological Survey.

- I’ve been studying some of
the latest ERTS imagery of Alaska.

Alaska is ideally
suited to remote sensing.

Transportation is limited.

Terrain is rugged.
It includes some of the highest

mountains and some of the greatest
snow fields in North America.

As this tectonic map indicates,
the geology is complex.

But we believe that, with the use
of the satellites, we can map out

the geology and help delimit
some of the mineral resources.

Our ERTS-A investigations in Alaska
started with a remarkably cloud-free

picture of the state that was
taken by the weather satellite –

the Nimbus weather
satellite in 1970.

- Studying this photo,
geologist Earnest Lathram

noted lines that seemed to
be hitherto undiscovered faults.

- Now we are using ERTS imagery to
determine the relationship between these

previously unsuspected faults and
the mineral resources of Alaska.

If we compare the mineral deposits
in Alaska to the linears shown

on the Nimbus photograph,
we can see a very definite relationship.

For instance, at the intersection
of these two linears, there has been

a major copper discovery
made recently.

Now, on one of our first ERTS images,
we see that, in this area,

there is indeed a fault along that strike.
- In Alaska, ERTS imagery is also being

used to improve and refine maps of the
permafrost – perennially frozen ground

that comprises 85% of the state’s terrain
in a variety of forms and that poses

engineering problems for
manmade undertakings.

[wind howling]

Another way ERTS imagery
is being used is to monitor

geologic hazards,
such as volcanic eruptions.



Glacial surges.

And other potential dangers
to man and his environment.

But it is not just in northern climates
that ERTS imagery is being used to

help deal with questions of ecology.
As biologists have long known,

wetlands are among our
most valuable ecological assets,

serving a series of lifecycle
and food production functions.

The work of Professor Richard
Anderson at American University

may prove a useful aid in
protecting the public interest.

In coastal areas, wetlands below
the mean high tide line legally

belong to the people at large,
but costly drawn-out court fights

often arise as to just where the boundary
line is in the hard-to-access terrain.

- The upper wetland boundary is
shown very clearly on this tree island.

Also the boundary between upland
and wetland is very clear in this area.

And I think that means we’re going to
be able to say a lot about a mean high

water line in wetlands, distinguishing
between what is publicly owned

and privately owned
wetland and avoid litigation

over wetland boundaries
in the future.


- In addition to remote
sensing from space,

ERTS has another
important capability.

It collects and forwards data
from censors on the Earth –

data, for instance, about river flow
and precipitation in New England,

a region with a long
history of flood disasters.

- Twenty-one died during this flood.

March 1936 was a springtime flood…
- Saul Cooper, in charge of the Flood

Control Division, New England Region, 
Army Corps of Engineers.

- Hurricane Diane in August 1955
caused this region its worst catastrophe.

Ninety people lost their lives,
and damages of almost

a half a billion dollars
were experienced.

To prevent such waste of
human life and resources,

the U.S. Army Corps of Engineers
has built 35 flood control reservoirs

strategically spotted
from Connecticut to Maine,

many local protective works,

and several hurricane barriers.

To maximize the effectiveness
of this system, we created

an automatic data collection
network with radio reporting.

- The network funnels
hydrologic data – river levels,

tidal elevations,

rainfall, and the like –
to the Corps’ regional control center

at Waltham, Massachusetts.

Now they are experimenting to
improve the system by using ERTS.

At some 25 stations, sensors are
producing hydrologic data as well as

water quality information where
rivers are being treated for pollution.

Every three minutes, this ERTS platform
transmits the data out to space.

If the spacecraft is on a line of sight,
it relays the data to a ground station.

The data is forwarded via telephone lines
to Waltham, where a computer processes

it to obtain information that is useful in
planning and invaluable in emergencies.

- Of course, the big payoff will come
during the next flood emergency.

In this room,
and around these tables,

we gather to coordinate
the flood control activities.

- Through data collection
and space imagery,

ERTS opens a door to a new
understanding of the world we live in.

The door is open to all.

At the center of the continent at
Sioux Falls, South Dakota,

the U.S. Geological Survey operates
a data center that receives, catalogs,

and stores a daily flow of ERTS
and high-altitude aircraft imagery.

Simultaneously, orders for pictures
pour in by phone and mail.

The computer queried
as to what is available.

Would you like to buy
an image of 100-mile-square piece

of the Earth
where you live?

The computer will search,
tell what’s available,

process your order, and
issue instructions to the laboratory.

Daily, a mounting volume of
imagery going to a long list of

subscribers at universities and
research agencies as well as

individuals around the world,
providing us with a more complete view

of that world than
we’ve ever had before.


With ERTS, man began the first
comprehensive inventory of his

Earthly resources, and he launched
a valuable new means of obtaining

information needed to manage those
resources for his future well-being.


ERTS, a new chapter in space,
is in fact a new chapter in man’s effort

to prove himself worthy
of his earthly heritage.

[Music continues to end]