SATELLITES

OrbitsSensors

LANDSAT NOAASPOT

RADARSATTERRAAQUA

6.3ccrs

Geostationary orbit Sun-synchronous orbit

http://liftoff.msfc.nasa.gov/RealTime/JTrack/3D/JTrack3D.html

6.3ccrs

SWATHAscending and descending node

Ascendingnode

Descendingnode

Satellite Orbits

6.3

Apogee

Perigee

Inclination

Period

point farthest from the earth

time to complete one orbitat 36,000 km the period equal the earth’s rotation (geostationary)

angle that the satellite track forms with respect to the equator at the ascending node(e.g. 90o means polar orbit)

point closest to the earth

Sun-synchronous orbit altitude of about 800 km

6.3

Orbit inclination carries the satellite track westward at a rate thatcompensates for the change in local solar time as the satellite moves

north to south (descending node always on sunlit side). All scenes are viewed at the same local solar time.

The illumination varies with seasons because of the tilt of the Earth.

Sensors that measure solar radiation reflected by the Earth alwaysdo so during the descending node. Thermal and radar satellites work

in both ascending and descending node.

Sensor types(1) across-track scanners (whiskbroom)

advantage: one sensor each band, easy calibration disadvantage: moving mirror prone to failure

(2) along-track scanners (pushbroom) advantage: no moving parts within a system disadvantage: large number of sensors, difficult to calibrate

(3) Image frame scanners, i.e., area arrays

Two types: (i) linear array, (ii) linear array with dispersing elements for multiple channels

LANDSAT

Multispectral Scanner Subsystem (Landsat 1-5)

6.4

Return Beam Vidicon (Landsat 1,2 and 3)Television-like images

Failed early in both Landsat 1 and 2and had some technical problems in Landsat 3

Because of failures of RBV, the MSS became the primary sensor of Landsat 1-3.

Swath of 185 kmResolution of about 79 x 57 m (~US football field)

Band 1: 0.5-0.6 m (green)Band 2: 0.6-0.7 m (red)

Band 3: 0.7-0.8 m (near-infrared)Band 4: 0.8-1.1 m (near-infrared)

Band 5 (Landsat 3 only): 10.4-12.6 m with 234x234 m2

Band Wavelength (m)

1 0.45-0.52 Blue-Green

LANDSAT THEMATIC MAPPER

Characteristics:

•Soil/vegetation discrimination, distinction between coniferous and deciduous forests; •Bathymetry/coastal mapping;•Cultural/urban feature identification•Penetration of clear water

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

2 0.52-0.60 Green

•Green vegetation mapping (measures reflectance peak);•Reflectance from turbid water•Cultural/urban feature identification

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

3 0.63-0.69 Red

•Vegetated vs. non-vegetated and plant species discrimination (plant chlorophyll absorption);•Cultural/urban feature identification

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

4 0.76-0.90 Near-Infrared

•Identification of plant/vegetation types, health, and biomass content; •Water body delineation; •Soil moisture

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

5 1.55-1.75 Short Wave Infrared

•Sensitive to moisture in soil and vegetation; •Discriminating snow and cloud-covered areas;•Penetration of thin clouds

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

6 10.4-12.5 Thermal Infrared

•Vegetation stress and soil moisture discrimination related to thermal radiation; •Thermal mapping (urban, water)•Relative brightness temperature

6.6CCRS

Band Wavelength (m)

LANDSAT THEMATIC MAPPER

Characteristics:

7 2.08-2.35 Short Wave Infrared

•Discrimination of mineral and rock types; •Sensitive to vegetation moisture content;•Hydroxyl ion absorption

6.6CCRS

ENHANCED THEMATIC MAPPER

LANDSAT 6LANDSAT 6 failed shortly after launch

6.7

ENHANCED THEMATIC MAPPER+LANDSAT 7

Launched: April 15, 1999

Better resolution for thermal channel: 60 m

A new 15-m panchromatic channel

Better calibration and data transmission.

A new 15-m panchromatic channel

NOAAAdvance Very High Resolution Radiometer

16.8

NOAA 1: Mission Date: December 11, 1970 to August 19, 1971

NOAA 16: Mission Date: September 21, 2000 to present

Resolution: 1.1 km at NadirSwath 2400 km (twice daily)Bands 0.58-0.68 m (visible) 0.725-1.10 m(near IR) 3.55-3.93 m (thermal) 0.3-11.3 m (thermal) 11.5-12.4 m (thermal)

10-bit dataoriginally for meteorological studies

NOAA-14 12/30/1994 - Present NOAA-15 05/13/1998 - Present NOAA-16 09/21/2000 - Present

HIRS/2 High Resolution Infrared Radiation (Temperature) Sounder Resolution 17.4 kmSwath 2240 km20 Infrared Bands

Other sensors on board NOAA 14

MSU Microwave Sounder UnitResolution 109.3 kmSwath 2348 km4 Bands

SARSAT Search And Rescue Satellite Aided TrackingBands: 121.5, 243 & 406 MHz

CCRS

SPOT -Système Pour l’Observation de la Terre

www.spot.com

The Spot program was developed by the French SpaceAgency CNES, in cooperation with Belgium and Sweden.

Altitude: 822 km Inclination: 98 degrees (i.e. near-polar orbit) Revolutions per day: 14 + 5/26 Period: 101 minutes Westward drift between successive ground tracks: 2823 km Cycle duration: 26 days Orbital revolutions per cycle: 369Crosses the equator at 10:30 am

Spot Image, created in 1982, is the first commercial companyestablished to distribute geographic information derived from

Earth Observation Satellites on a worldwide basis. SPOT 1 was launched February 21, 1986

SPOT 4 was launched March 24, 1998

6.8

SPOT 42 HRVIR Haute Resolution Visible Infrarouge (HIGH RESOLUTION VISIBLE INFRARED)

Multispectral PanchromaticResolution 20 m 10 mSwath 60 km 60 kmBand (m) 0.50-0.59 0.61-0.68

0.61-0.68 0.79-0.89 1.58-1.75

VMI Vegetation Monitoring InstrumentResolution 1 kmSwath 2000 kmBands: (m) 0.43-0.47 0.50-0.59

0.61-0.68 0.79-0.89 1.58-1.75

Direction of flight

The main differences between Landsat and SPOT

Landsat SPOT

Sensor whiskbroom pushbroom

Motion control Fixed nadir view pointable

Spatial Resolution

30 m (TM) 20 m (HRV)10 m (HRV): SPOT5

Number of bands 7 (TM)

8 (ETM)

4

Time Series Since 1972 Since 1986

The main differences between AVHRR and VGT

AVHRR VGT

Sensor whiskbroom pushbroom

Spatial Resolution 1.1 km at nadir

increasing with

view zenith angle

(VZA)

Fixed at 1.1 km

at all view angle

(increase slightly

with VZA)

Number of optical bands

2 4

Number of thermal bands

3 0

Time series Since 1970 Since 1998

SPOT VEGETATION (VGT)

Similar to AVHRR, but was designed for vegetation.

CCD linear arraySame bands as HRVIR

SAWTH of 2,200 kmResolution of 1 km at nadir (regional mode)

6.8

SPOT 52.5 m Panchromatic, 10 m HRVIR

Launched 4 May 2002

This image of Monterey Bay was created by merging two panchromatic and two multi-spectral SPOT images together. Sharpening and natural colours were created as well. The ocean area was rendered using a bathymetric elevation model with drapedcolours. The ocean waves, boat wakes, and other reflections were added by algebraically merging texture maps of the panchromatic SPOT images with the draped colour elevation file. Monterey Bay is equivalent to the Grand Canyon under sea in terms of area and depth.

Hammon, Jensen, Wallenhttp://www.hjw.com/montbay.html

Active microwave sensors1. Bands: Ka (0.75-1.1 cm), K (1.1-1.67 cm), Ku (1.67-2.4 cm), X (2.4-3.75 cm), C (3.75-7.5 cm), S (7,2-15 cm), L (15-30 cm), P (30-100 cm)

2. Polarization: HH, HV, VH, VV Like polarized, HH, VV Corss polarized: HV, VH

Source

Magnetic Component

Electric

ComponentH

V

RADARSAT

7.10CCRS CSA

The RADARSAT project, led by the Canadian Space Agency, builds on the history of achievements in remote sensing and space technologies by the Canada Centre

for Remote Sensing (CCRS), part of Natural Resources Canada.

C-BAND

Swath: 35 - 500 kmResolution:10-100 m

Sun-synchronous

Equator: 06:00 am

Radarsat International Inc.Richmond British Columbia

Inclination: 98.6o

Period: 100.7 min.

RADARSAT 2

Scheduled for launch in Early 2004

High Resolution 3 x 3 m

Multi Polarizationhorizontal (HH), vertical (VV) and cross (HV & VH)

Advanced Earth Observing Satellite (ADEOS)Japan (launched on August 17, 1996)

8 SensorsAltitude: 830 km

Operational for 8 months: October 30, 1996 to June 30, 1997

POLDER sensor: Multiangle view of 6x7 km2 of the whole globe.

Goal is to find BRDF signature of different cover typesfor classification and biophysical parameters retrieval.

NEW POLDER on board ADEOS II

(Launched December 2002, Lost October 2003)

POLDER First ImagesConventional (right)

Polarized (left)

http://www.jpl.nasa.gov/webcast/seawinds/

NASA EOS Terra (was AM-1) missionLaunched 18 December

Five sensors:1. Moderate-resolution Imaging Spectroradiometer (MODIS, USA)

2. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER, Japan)

3. Clouds and the Earth's Radiant Energy System (CERES, USA)

4. Multi-angle Imaging Spectro-Radiometer (MISR, USA) 5. Measurements of Pollution in the Troposphere

(MOPITT, Canada)

EOS TERRA (was AM-1) NASA

MODerate-resolution Imaging Spectroradiometer (MODIS)

Spectral range 0.4-14.4 µm Spectral coverage ± 55°, 2330 km swath

Spatial resolution: 250 m (2 bands), 500 m (5 bands), 1000 m (29 bands) at nadir

20.5 http://modarch.gsfc.nasa.gov/EOS-AM/

Launch: December 1999

Sun-synchronous orbit, 10:30 a.m. descending node5 sensors

Global Mosaic of MODIS

MOPITT

Resolution: 22 kmSwath: 640 km

Measuring methane andCarbon monoxide

ASTER

Resolution: 15-90 mBands: 14Swath: 60 km

Measuring:TemperatureEmissivityReflectanceElevation

MISR

                                                 

           

Resolution: 275 m

Bands: 4

Swath: 360 km

Angles: 9

Measuring:

Aerosols

Clouds (amount, type, ht.)

Vegetation Structure

CERES

Resolution: 20 kmBands: 3 (SW, T, total solar energy)

Measuring:Cloud amountCloud temperature

AMSR/E- Advanced Microwave Scanning Radiometer-EOS

MODIS-Moderate Resolution Imaging Spectroradiometer

AMSU-Advanced Microwave Sounding Unit

AIRS- Atmospheric Infrared Sounder

HSB- Humidity Sounder for Brazil

CERES- Clouds and the Earth's Radiant Energy System

EOS AUQA (was PM-1), NASA

Six Instruments onboard:

May 4, 2002 2:55 a.m. PDT

Vandenberg Air Force Base, CA

RADARSAT- Snow mapping of Ottawa

Agricultural fields (A and B), the Ottawa International Airport (C), the Ottawa River (D) and the city of Ottawa (E).

January 19, 1996

•To investigate the operational use of VGT as a substitute for AVHRR for crop and forest fire monitoring.

VESNA: VEGETATION/SPOT for Northern applications

Co-Principal Investigators: Jing Chen and Josef Cihlar Canada Centre for Remote Sensing

•To extend and refine the methodology previously developed for processing AVHRR data to the VGT/SPOT system.

•To assess the advantages of VGT spectral bands in deriving biophysical parameters.

•To explore the usefulness of VGT/SPOT for vegetation carbon budget estimation in comparison with AVHRR.

http://www.spotimage.fr/data/images/vege/vegetat/book_1/e_frame.htm

Main conclusion: VGT is much better than AVHRR