Lecture9 Flashcards
(26 cards)
radiometric resolution
The sensitivity of a detector to differences in signal strength as it records.
“how many gray shades” a sensor can resolve (e.g. 8 bit = 0 to 255 shades, or 10-bit = 0 to 1023)
8-bit
2^8=256, or 0 to 255
10-bit
2^10 = 1024, or 0 to 1023
Why panchromatic have higher spatial resolution than separate BGR spectra?
Stronger signal / more spectral information per pixel
LDCM
Landsat Data Continuation mission (Landsat 8)
Landsat specifications
Multi-spectral remote sensing: Landsat
• Sun-synchronous near polar orbits
• Inclination 99° and 98.2°
• 919 km altitude (Landsat 1, 2, 3), 705 km for the others
• Orbits the earth every 103 minutes (Landsat 1, 2, 3)
• Cross latitude at approximately the same local time (equator 9:30 to 10:00 am)
Distance between Landsat orbits is because…
…earth is moving
Landsat coverage (what augmented by and what type of orbit? What suited for?)
Augmented by Tracking and Data Relay Satellite
System (TDRS)
- Geosynchronous
- Medium resolution is well suited to systematic global coverage

TDRS
Tracking and Data Relay Satellite
System
Landsats sensors
Landsats sensors (MSS, TM, ETM+, OLI and TIRS) carried combinations of 7 types of sensors:
– Return Beam Vidicon (RBV) camera systems
• Imaged entire ground scene instantaneously
• Improved cartographic fidelity
• Only flew on Landsats 1-3
– Multispectral Scanner (MSS) systems on LS4-5
– Thematic Mapper (TM) on LS4-5
– Enhanced Thematic Mapper (ETM) on LS6
– Enhanced Thematic Mapper Plus (ETM+) on LS7
– Operation Land Imager (OLI) on LS8
– Thermal Infrared Sensor (TIRS) on LS8
RBV camera systems
– Return Beam Vidicon (RBV) camera systems
• Imaged entire ground scene instantaneously
• Improved cartographic fidelity
• Only flew on Landsats 1-3
Beware that numbers of channels differ from different Landsats
MSS bands on Landsat 1-5
Multispectral scanner
Band 4/1 (0.5-0.6 μm) Green
– Water features (large penetration depth)
– Sensitivity to turbidity (suspended material)
– Sensitivity to atmospheric haze
Band 5/2 (0.6-0.7 μm) Red
– Chlorophyll absorption region
– Good contrast between vegetated and non-vegetated areas
– Haze penetration better than band 4
Band 6/3 (0.7-0.8 μm) and Band 7/4 (0.8-1.1 μm) NIR
– Similar for most surface features
– Good contrast between land and water (water is strong absorber in NIR)
– Both bands excellent haze penetration
– Band 7 for discrimination of snow and ice
Landsat uses of MSS Band 4/1 (0.5-0.6 μm) Green
– Water features (large penetration depth)
– Sensitivity to turbidity (suspended material)
– Sensitivity to atmospheric haze
Landsat uses of MSS Band 5/2 (0.6-0.7 μm) Red
– Chlorophyll absorption region
– Good contrast between vegetated and non-vegetated areas
– Haze penetration better than band 4 (green)
Landsat uses of MSS Band 6/3 (0.7-0.8 μm) and Band 7/4 (0.8-1.1 μm) NIR
– Similar for most surface features
– Good contrast between land and water (water is strong absorber in NIR)
– Both bands excellent haze penetration
– Band 7 for discrimination of snow and ice
Landsat Thematic Mapper (TM) bands (LS 4 and 5)
On LS 4 and 5
Band 1 (0.45-0.52 μm) Blue-green Band 2 (0.52-0.60 μm) Green Band 3 (0.63-0.69 μm) Red Band 4 (0.76-0. 90 μm) Near IR Band 5 (1.55-1. 75 μm) Mid IR Band 6 (10.4-12. 50 μm) Thermal IR Band 7 (2.08-2. 35 μm) Mid IR
Landsat uses of Thematic Mapper Band 1 (0.45-0.52 μm) Blue-green
– Good water penetration (bathometry and coastal studies)
– Differentiating soil and rock surfaces from vegetation detection of cultural features
– Smoke plumes
– Most sensitive to atmospheric haze
Landsat uses of Thematic Mapper Band 2 (0.52-0.60 μm) Green
– Water turbidity differences
– Sediment and pollution plumes
– Discrimination of broad classes of vegetation
Landsat uses of Thematic Mapper Band 3 (0.63-0.69 μm) Red
Strong chlorophyll absorption(vegetation versus soil)
Urban versus rural areas
Landsat uses of Thematic Mapper Band 4 (0.76-0. 90 μm) Near IR
Different vegetation varieties and conditions
Dry versus moist soil
Coastal wetland, swamps, flooded areas
Landsat uses of Thematic Mapper Band 5 (1.55-1. 75 μm) Mid IR
Leaf tissue water content (reflection less as more water  )
Moisture content of soil
Snow (light tone) versus cloud (dark tone)
Landsat uses of Thematic Mapper Band 6 (10.4-12. 50 μm) Thermal IR
Heat mapping applications
Radiant surface temperature: range -100 C to +150 C
NOTE: 120 m spatial resolution–need larger pixel to pick up signal
Landsat uses of Thematic Mapper Band 7 (2.08-2. 35 μm) Mid IR
Absorption band by hydrous minerals (clay, mica) Lithologic mapping (clay zones)
Landsat 7 Enhanced Thematic Mapper (ETM+)
• April 15, 1999-present
• WRS-2 path/row system
• Sun-synchronous orbit at altitude of 705 km (438 mi)
• 233 orbit cycle every 16 days covers the complete globe (except the highest polar
latitudes)
• Inclined 98.2°
• Orbiting the Earth every 98.9 minutes
• Equatorial crossing time: 10:00 am ±15 minutes
• Each scene is 185 wide x 170 km high (115 mil x 105 mi)
• 8-bit quantization (28 DN values)
• on-board calibration
Enhanced Thematic Mapper (ETM+) bands
Band # (Channel)
Wavelength range (μm)
Spectral Location
Resolution (m)
1 2 3 4 5 6 7 8
0.450-0.515 0.525-0.605 0.630-0.690 0.775-0.900 1.550-1.750 10.40-12.50 2.090-2.350 0.520-0.900
Blue-green Green Red Near IR Mid IR Thermal IR Mid IR
?
30 30 30 30 30 60 30 15
