Current and Future Remote Sensing Systems Lecture 2

Current and Future Current and Future Remote Sensing SystemsRemote Sensing Systems

Lecture 2Lecture 2

Prof. Dr. Scott Madry

Research Associate Professor,

University of North Carolina, USA

Current and Future Current and Future Remote Sensing SystemsRemote Sensing Systems

ResolutionResolution Four kinds of resolution define user needs: Spatial Resolution: How small an object do you need

to see (pixel size) and how large an area do you need to cover (swath width)

Spectral Resolution: What part of the spectrum do you want to measure

Radiometric Resolution: How finely do you need to quantify the data (6 bit=0~63, 8 bit=0~255, 10 bit=0-1023)

Temporal Resolution: How often do you need to look

Different sensors and resolutionsDifferent sensors and resolutions

Sensor Spatial Spectral radiometric Temporal

AVHRR 1.1 and 4 Km 2400 Km

4 or 5 bands.58-.68, .725-1.1, 3.55-3.93, 10.3-

11.3, 11.5-12.5µm

10 bit(0-1023)

12 hours(1 day, 1

night)

Landsat MSS 80 meters185 Km

4 bands.5-.6,.6-.7,.7-.8,.8-1.1

6 bit(0-63)

16 days

Landsat TM 30 meters185 Km

7 bands.45-.52, .52-.6, .63-.69, .76-.9,

1.55-1.75, 10.4-12.5, 2.08-2.3µm

8 bit(0-255)

14 days

SPOT P 10 meters60 Km

1 band51-73µm

8 bit(0-255)

26 days(2 out of 5)

SPOT X 20 meters60 Km

3 bands.5-.59,.61-.68,.79-.89µm

8 bit(0-255)

26 days(2 out of 5)

How good can we get?How good can we get?

A 2 meter mirror in orbit gives a theoretical limit of about 2 inches (degraded by wind, smog, etc.)

SALT-II treaty said existing ICBMs could not be altered more than 5% in diameter

– Smallest Soviet ICBM then was SS-11, 6 feet (~2 m) in diameter, 5% is 3.6 inches (10 cm)

– US would not sign a treaty that it could not routinely verify by National Technical Means…

Spectral resolution Spectral resolution MSS bands 4 and 5MSS bands 4 and 5

MSS bands 6 and 7MSS bands 6 and 7

INFRARED 1 INFRARED 2

Water absorbs IR energy-no return=black

Swath widthSwath width

Landsat-185 km (100 mi)80 m = 40 MB-4 bands (MSS)30 m = 320 MB-6 bands (TM)10 m = 342.25 MB-1 band 5 m = 1.369 GB -1 band 1 m = 34.225 TB – 1 band

How small do we need?

How much data can we store

And process?

Remote Sensing SystemsRemote Sensing Systems

There are many ways remote sensing is used:Geostationary weather monitoringPolar remote sensingNational security, cartography and mappingNatural resource managementDisaster management-fire, earthquakes, etc.Data for Geographic Information Systems (GIS)Atmospheric and Marine science and applicationsEarth systems science, and many, many othersNew hi-resolution systems are equal to aerial photos

Polar orbiting remote sensingPolar orbiting remote sensing

Polar orbit is 700-900 km constant sun angle 1,000-1m resolution

NOAA Polar Orbiters and Russian Meteors are Public environmental satellites-data in the clear

Many other new national and commercial systems encrypt their data

Applications-Change DetectionApplications-Change Detection

The ability to monitor change is one of the benefits of remote sensing

We can monitor human and natural changes in the landscape

1988 Yellowstone Fires1988 Yellowstone Fires

Thermal imagery-temperatureThermal imagery-temperature

Water analysis-nuclear power cooling ponds Real time fire management

The first 25 years of Civil Remote Sensing

New RSNew RS

Many new systems are in development

New gov’t and Commercial systems as well

NOAA POESNOAA POES

Polar Orbiting Environmental Satellite

Two satellites in orbitOne satellite crosses the equator

at 7:30am local time, the other at 1:40pm local time.

Advanced Very High Resolution Radiometer (AVHRR) sensor

AVHRR ImageAVHRR Image

Thermal channelThermal channel

AVHRR Sea Surface AVHRR Sea Surface TemperatureTemperature

Thermal AVHRR provides water temperature data

Global vegetation productivityGlobal vegetation productivity

AVHRR-land CZCS

phytoplancton-water

Remote sensing provides global information about the health of spaceship Earth

SeaWiFSSeaWiFS

Aug ‘97 launch Swath Width 2,801 km

LAC/HRPT (58.3 degrees) Swath Width 1,502 Km GAC (45 degrees) Spatial Resolution 1.1 km LAC, 4.5 km GAC Real-Time Data Rate 665 kbps Revisit Time 1 day Digitization 10 bits

SeaWiFSSeaWiFS

Defense Meteorological Defense Meteorological Program Satellite (DMSP)Program Satellite (DMSP)

The Defense Meteorological Satellite Program (DMSP) is a DOD program.

OLS- Operational Linescan System

Similar to AVHRR but with unique low light night imager

4 satellites (3 day/night, 1 dawn/dusk)

The world at nightThe world at nightNovember 27, 2000November 27, 2000

The Landsat Program-First Civil RSThe Landsat Program-First Civil RS The Landsat program was the first civil RS program 1965: NASA initiates an Earth Resources Survey (ERS) Program

to develop methods for remote sensing of earth resources from space. Dept. of Agriculture joins in the program with studies of remote sensing applications in geology, hydrology, geography and cartography.

‘72 launch of ERTS-1 (Earth Resource Technology Satellite) Multi-Spectral Scanner-80 m

Landsat 2 and 3 were similar Landsat 4 and 5 had new Thematic Mapper (TM) 30m Landsat 6 went swimming Landsat 7 has 15 m by NASA for Mission to Planet Earth. Data

is provided at cost (about US$ 250 per scene). Landsat 8? Will follow 7 for continuity? Data buy? NPOESS?

ERTS-1ERTS-1

Earth Resources Technology Satellite-1

NASA Renamed Landsat

(Seasat) First images in late 1972 Was the first civil remote

sensing satellite Based on the Nimbus bus

Landsat regional mosaicLandsat regional mosaic

Landsat 4-5 Thematic Mapper (TM)Landsat 4-5 Thematic Mapper (TM)

Rotating scan mirror systemRotating scan mirror system

Landsat 6Landsat 6

The first “underwater” remote sensing satellite

26 October 1992 Contract for Landsat 6 development

– General Electric received $398 million contract to develop the satellite, including Hughes’ $120 million infrared thematic mapper.

05 October 1993 Landsat 6 launch failure: kick-motor malfunction.

‘‘Commercialization’ of LandsatCommercialization’ of Landsat Landsat was

commercialized by Pres. Reagan

EOSAT formed Sales dropped Commercial data

will now be high resolution

Medium res will return to “public good”

Landsat 7Landsat 7

15 m ETM+ (enhanced TM) sensor May, 1999 launch Oct.’92 Land remote sensing policy act a panchromatic band with 15m spatial

resolution-fully co-registered w/30m on-board, full aperture, 5% absolute

radiometric calibration a thermal IR channel with 60m spatial

resolution

Goddard Space Flight Center in Beltsville, Md.

Landsat Data Continuity Mission (LDCM)Landsat Data Continuity Mission (LDCM)

The Land Remote Sensing Policy Act of 1992 directed NASA and the USGS to assess various system development and management options for a satellite system to succeed Landsat 7

Although six of the previous seven Landsat satellites have been government owned and developed, a preference is expressed in the act for “private sector funding and management”

NASA and the USGS are working together on the Landsat Data Continuity Mission (LDCM) to ensure the continuity of Landsat data through private sector investment in the development of the LDCM system

Resource21 and DigitalGlobe (withdrew)

In ConclusionIn Conclusion

There are many remote sensing systems in use and in development

Why are there so many? National pride, dual use, commercial interests…

There will be more and varied systemsData integration and analysis are important

AssignmentAssignment

Q1. Listen to the Video Lecture 2 of Dr. Scott Madry to find out how long did landsat 6 work and how did it end?

Q2. Name all the RS Satellites launched by India?

Q3. Which country launched the SPOT Satellites?

Q4. Which Satellites was launched by China and Brazil together?