Images

From

Space

Sputnik 1, Oct. 1957 – USSR

• First artificial satellite to orbit earth

• Transmitted radio signals for 3 weeks before batteries died. Orbited for 2 more months before burning up on re-entry.

• Officially started the “space race”

The Beep Heard Round the World

International Geophysical Year

July, 1957 – December, 1958

• International science collaborative with 67 countries participating

• Eleven earth sciences represented: - aurora and airglow, cosmic rays, geomagnetism,

gravity, ionospheric physics, longitude and latitude determinations (precision mapping), meteorology, oceanography, seismology, and solar activity.

• IGY Legacy: - Pioneered use of rocketry to study atmosphere

- Discovery of the Van Allen Radiation Belts

- Confirmation of mid-ocean ridges. Plate tectonics not officially recognized until 1970s

- Antarctic Treaty – peaceful scientific research

Fallout from Sputnik 1

• US Gov.t downplayed the significance of the launch due to previous knowledge via U-2 surveillance and intel reports.

• American public and world were captivated and believed the balance of power had shifted from West to East.

‐ Directly led to the creation of NASA, the lunar program, the Defense Advanced Research Projects Agency (DARPA) and a renewed interest in math and science in education.

Explorer 1 Jan., 1958 – USA

• Carried a cosmic ray detection package and discovered the Van Allen Radiation Belts.

• Returned data for ~4 months and orbited for another 12 years before re-entry.

• More than 90 Explorer missions followed.

Back in the Game

Corona Program 1959 – 1972 – USA

• Early missions full of failed launches

• First Reconnaissance images from space – Aug. 1960. Film ejected and recovered by plane

• Salt plug would dissolve if recovery missed

Surveillance From Space

Skylab, May, 1973 – USA

• Largest manned space station at the time

• Carried the Earth Resources Experiment Package (EREP) designed to view the Earth with sensors that recorded data in visible, infrared, and microwave spectral regions.

• Tested high spatial resolution camera systems with film return capability.

• Occupied for 24 weeks by 3, 3-person crews. Burned up on re-entry in 1979.

Command/

Service

Module (CSM)

Kennen KH-11, 1976 – USA • First Electronic Imaging

Optical Satellite for real-time observation

• Images returned via satellite relay. Upper transmissions at frequencies that don’t penetrate atmosphere, so undetectable from ground.

• Operational resolution ~ 5 inches??

Hubble Space Telescope

Surveillance Gets Serious

• The Earth Resources Technology Satellite (ERTS), later designated Landsat, provided repetitive multispectral observations of the Earth.

• World's longest, continuously acquired collection of space-based land remote sensing data

• The images, archived in the United States and at Landsat receiving stations around the world, are a unique resource for global change research and applications in agriculture, geology, forestry, regional planning, education and national security.

Landsat, 1972 - Present

World’s longest running satellite data collection program

Landsat Spectral, Spatial and Temporal Resolution(s)

79 m

79 m

79 m

79 m 79 m

79 m

79 m

79 m

30 m

30 m

30 m

30 m

30 m

120 m

30 m

30 m

30 m

30 m

30 m

30 m

60 m

30 m

15 m

30 m

30 m

30 m

30 m

30 m

30 m

30 m

15 m

100 30 m

100 30 m

16 Days 16 Days 16 Days 16 Days 18 Days

30 m

Satellites vs

Sensors

Satellite Sensor

Landsat 1-3 MSS

Landsat 4-5 MSS; TM

Landsat 7 ETM+

Landsat 8 OLI; TIRS

ETM+ – Enhanced Thematic Mapper Plus

MSS – Multispectral Sensor

OLI – Operational Land Imager

TIRS – Thermal Infrared Sensor

TM – Thematic Mapper

Landsat 8

Band 1: 0.45-0.52 µm (blue) Provides increased penetration of water bodies, as well as supporting analysis of land use, soil, and vegetation characteristics.

Band 2: 0.52-0.60 µm (green) This band spans the region between the blue and red chlorophyll absorption bands and therefore corresponds to the green reflectance of healthy vegetation.

Band 3: 0.63-0.69 µm (red) This is the red chlorophyll absorption band of healthy green vegetation and represents one of the most important bands for vegetation discrimination.

Spectral Cover of Landsat Sensors (TM, ETM+)

• Band 4: 0.76-0.90 µm (Near-infrared). This band is responsive to the amount of vegetation biomass present in the scene. It is useful for crop identification and emphasizes soil-crop and land-water contrasts.

• Band 5: 1.55-1.75 µm (Mid-infrared) This band is sensitive to the amount of moisture

in plants and therefore useful in crop drought and in plant vigor studies.

• Band 6: 10.4-12.5 µm (Thermal infrared) This band measures the amount of infrared radiant flux emitted from surface.

• Band 7: 2.08-2.35 µm (Mid-infrared) This is an important band for the discrimination

of geologic rock formation. It is effective in identifying zones of hydrothermal alteration in

rocks.

Spectral Cover of Landsat Sensors (TM, ETM+)

Landsat-7 ETM+ Scan Line Corrector (SLC) Data

Landsat 7 ETM+ SLC-off data refers to all Landsat 7 scenes collected after May 31, 2003, when the Scan Line Corrector (SLC) failed.

• Products have gaps (~25% of total area), but are still useful and maintain the same radiometric and geometric corrections as data collected prior to the SLC failure.

• Gaps can be filled by substituting pixels from scenes collected on different days or other 3rd party tools.

Landsat Ground Station Network

Stations receive both real-time and recorded imagery and route satellite health telemetry to the Mission Operations Center. Imagery is passed to USGS EROS Center for additional processing.

Landsat Image Catalog – Worldwide Reference System

Rhode Island: Path 12/Row 31

Landsat Image Referencing

Landsat scene – Single image obtained by the sensor. 183km wide x 170km long

USGS Landsat Look – Worldwide Reference System

https://landsatlook.usgs.gov/

Landsat Image Catalog – Worldwide Reference System

Landsat Applications National Land Cover Database (NLCD)

Endless Possibilities • Habitat mapping • Mapping flood

plains • Wildfire impacts • Nearshore

bathymetry

• Watershed management

• Coral reef health • Invasive species monitoring

• Disaster management

• Agricultural insurance fraud

• Deforestation • Wildlife corridors • Impervious surfaces

• Mapping geologic landforms

• Cartographic mapping

• Renewable energy siting

And on and on. . .