Advanced Very High Resolution Advanced Very High Resolution - PowerPoint PPT Presentation

Advanced Very High Resolution Advanced Very High Resolution Radiometer (AVHRR) Radiometer (AVHRR) AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

http://www2.ncdc.noaa.gov/docs/klm/html/c3/sec3-1.htm AVHRR NRM641 Spring 2010

http://coastwatch.noaa.gov/ http://coastwatch.noaa.gov/ AVHRR NRM641 Spring 2010

• Onboard NOAA Satellites • Onboard NOAA Satellites • AM and PM polar orbiting • AM and PM polar orbiting • High temporal resolution • High temporal resolution • Multiple coverage using four • Multiple coverage using four NOAA satellites NOAA satellites • 8-10 passes a day in Alaska • 8-10 passes a day in Alaska • 2400 km swath width • 2400 km swath width AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

• Tradeoff: High Temporal Resolution(daily) • Tradeoff: High Temporal Resolution(daily) • Low Spatial Resolution • Low Spatial Resolution • Historic data since 1981…. • Historic data since 1981…. AVHRR NRM641 Spring 2010

• Instantaneous Field of View 1.1km only at nadir • Instantaneous Field of View 1.1km only at nadir Huge scan angle: +/- 55 degrees Huge scan angle: +/- 55 degrees AVHRR NRM641 Spring 2010

Bidirectional Reflectance Problem Bidirectional Reflectance Problem AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

AVHRR Data Problems AVHRR Data Problems • Broad spectral bands compared to • Broad spectral bands compared to instruments designed for land remote instruments designed for land remote sensing sensing AVHRR NRM641 Spring 2010

AVHRR Data Problems AVHRR Data Problems • No on-board calibration of red or near- • No on-board calibration of red or near- infrared channels infrared channels AVHRR NRM641 Spring 2010

Degradation in spectral Response Degradation in spectral Response (from ocean observations) (from ocean observations) 1.1 NOAA9 1.05 NOAA7 NOAA16 1 NOAA14 0.95 1 1 NOAA11 l l e e 0.9 n n n n a a 0.85 h h C C 0.8 1980 2005 1980 2005 1 . 3 1 . 2 5 N O A A 7 N O A A 1 1 2 1 . 2 2 N O A A 1 6 N O A A 9 l l e e N O A A 1 4 1 . 1 5 n n n n a a 1 . 1 h h C C 1 . 0 5 1 1 9 8 0 1 9 8 5 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 Y e a r AVHRR NRM641 Spring 2010

AVHRR Data Problems AVHRR Data Problems • Lacks onboard calibration. • Lacks onboard calibration. • Broad spectral bands • Broad spectral bands • Orbital drift • Orbital drift AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

Normalized Difference Vegetation Index Normalized Difference Vegetation Index (NDVI) (NDVI) Surface NDVI Surface NDVI Soil < 0 Soil < 0 Water <0 Water <0 Willow Shrub 0.3-0.5 Willow Shrub 0.3-0.5 Birch Forest 0.6-0.8 Birch Forest 0.6-0.8 AVHRR NRM641 Spring 2010

Red Near-IR Reflectance Reflectance Dry Soil High High Urban High High Clear Water Low Low Muddy Water High Low Burned Area Low Low Ocean Water Low Low Sand Dunes High High Clouds High High Vegetation Low High AVHRR NRM641 Spring 2010

Maximum NDVI Compositing Maximum NDVI Compositing • Minimize cloud-contaminated pixels • Minimize cloud-contaminated pixels • Minimize off-nadir pixels • Minimize off-nadir pixels • Capture peak of photosynthetic activity • Capture peak of photosynthetic activity AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

GLIMMS ( Global Inventory Modeling and Mapping Studies ) NDVI data GLIMMS ( Global Inventory Modeling and Mapping Studies ) NDVI data http://glcf.umiacs.umd.edu/data/gimms/ http://glcf.umiacs.umd.edu/data/gimms/ • Free, ftp download • Free, ftp download • Global, 8-km pixels • Global, 8-km pixels • 15-day composite period • 15-day composite period • 1981-2006 • 1981-2006 • Corrected for calibration and orbit drift • Corrected for calibration and orbit drift • Adjusted for major volcanic eruptions • Adjusted for major volcanic eruptions AVHRR NRM641 Spring 2010

June 1-15 bimonthly NDVI 1982 June 1-15 bimonthly NDVI 1982 AVHRR NRM641 Spring 2010

June 16-30 bimonthly NDVI 1982 June 16-30 bimonthly NDVI 1982 AVHRR NRM641 Spring 2010

July 1-15 bimonthly NDVI 1982 July 1-15 bimonthly NDVI 1982 AVHRR NRM641 Spring 2010

Alaska 1-km Composite NDVI data Alaska 1-km Composite NDVI data • From USGS EROS Data Center • From USGS EROS Data Center • Not free, not corrected • Not free, not corrected • 15-day composite period • 15-day composite period • 1991-2005 • 1991-2005 • NDVI scaled to 0-250 • NDVI scaled to 0-250 • Channels 1-5 included • Channels 1-5 included • Date of pixel observation included • Date of pixel observation included AVHRR NRM641 Spring 2010

AVHRR NRM641 Spring 2010

http://agdc.usgs.gov/data/usgs/erosafo/ak_avhrr/ak_avhrr_ndvi.html#2000 http://agdc.usgs.gov/data/usgs/erosafo/ak_avhrr/ak_avhrr_ndvi.html#2000 • Phenology metrics derived from NDVI • Phenology metrics derived from NDVI • Free • Free • 1991-2000 • 1991-2000 AVHRR NRM641 Spring 2010

References References • Hope et al. 1999. Estimating lake area in an Arctic • Hope et al. 1999. Estimating lake area in an Arctic landscape using linear mixture modelling. Int. J. landscape using linear mixture modelling. Int. J. Remote Sensing. 20:829-835. 102:13521-13525. Remote Sensing. 20:829-835. 102:13521-13525. • Goetz et al. 2005. Satellite-observed photosynthetic • Goetz et al. 2005. Satellite-observed photosynthetic trends across boreal North America associated with trends across boreal North America associated with climate and fire disturbance. PNAS. climate and fire disturbance. PNAS. • Raynolds et al. 2008. Relationship between satellite- • Raynolds et al. 2008. Relationship between satellite- derived land surface temperatures, arctic vegetation derived land surface temperatures, arctic vegetation types, and NDVI. Remote Sensing of Environment. types, and NDVI. Remote Sensing of Environment. 112:1884-1894. 112:1884-1894. AVHRR NRM641 Spring 2010