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1. NASA Direct Readout Active Fire and Burn Scar Mapping Products Louis Giglio
Science Systems & Applications, Inc. / University of Maryland
International EOS/NPP Direct Readout Meeting
1 April 2008
3. Satellite-Based Active Fire Products Identify where fires are actively burning at time of satellite overpass (and implicitly when they are burning)
Possibly provide additional information about fires at time of satellite overpass
Intensity, average temperature, instantaneous size, rate of combustion, injection height, etc.
6. Mean Terra MODIS Fire Radiative Power
7. MODIS Direct Readout Active Fire Status Matches official MODIS fire detection algorithm (currently Collection 5)
Developed in the MODIS Rapid Response System
Initial release ~2003 (Collection 3)
Refinements planned for Collection 6
Additional refinements planned for Direct-Readout release
8. Direct Readout Implementation Code written in C
Stand alone, non-ECS version
SDP Toolkit, PCFs, run-time environment variables not required
Not a pig
Fast (~1 minute/granule @ 1 GHz)
Small memory footprint (< 10 MB)
Source code available from GSFC DRL
http://directreadout.sci.gsfc.nasa.gov/
9. Planned Refinements Optional compact fire location output file
Algorithm improvements
Reduce false alarms in problem areas
Recognize optically thick smoke (vs. cloud)
Improve detection confidence estimate (again)
Regional customization
Suggestions/complaints welcome from DR community
10. Regional Customization Global algorithm for global application
Always a balance between omission and commission errors
Several known independent efforts to date
SE USA, Australia, SE Asia, Italy, others?
Standard multi-region version of code planned
South Africa
Ocean only (!)
Continental United States
11. Caveat Fire location-only products omit useful information
ASCII (text) files
Lack spatial context
cloud cover, missing data, water
Sometimes inappropriate for research purposes (yet used anyway!)
13. MODIS Active Fire Validation (2) Fire mask using ASTER imagery
Sometimes degraded by frequent ASTER saturation
Fire radiative power retrieval using ASTER
Cannot use simple middle-infrared band approach used for MODIS with ASTER
Often degraded by frequent ASTER saturation
Simulated MODIS imagery
Independent burn scar maps
Usually not able to evaluate false alarm rate
16. Example Simulation Results MODIS
Temperate deciduous rainforest
Night
0° scan angle
Summer
No background fires
17. NPP/NPOESS Active Fire EDR Current Status (1) VIIRS instrument generally in good shape
Some outstanding issues relevant to fire
On-board aggregation of saturated M15 pixels (possibly moot)
Band-to-band coregistration
18. NPP/NPOESS Active Fire EDR Current Status (2) Current code is repackaged Collection 4 MODIS code
Current product is simply a list of fire locations
Restricts both science and operational use
Science Team advocating MODIS-like product
fire mask (cloud, fire, no observation, etc.)
FRP
Bureaucratic hurdles for changing product are substantial
All parties have good intentions but fire products have extremely low priority not a true EDR but an ARP
Solution: Develop independent code and product for DR and science communities
19. Satellite-Based Burned Area Products Map spatial extent of post-fire burn scars over a particular time period
22. Official MODIS Burned Area Product Roy et al. (2002, 2005) BRDF-based approach
500-m, daily resolution
Production commenced in late 2006
Under evaluation by Science Team and external collaborators
Full release as early as summer 2008
Immediate reprocessing planned
Computationally demanding
DR version not yet ready
24. Consistency conceptual scheme
25.
looking at one algorithm step: Production, first of a kind, multiannual product Production, first of a kind, multiannual product
26. A closer look at the monthly product
Tile h17v06 2000306
(November 2000)
27. A closer look at the monthly product
31. Approach Use cleaned active fire maps to select burned and unburned training samples from temporal composites
Extract conditional PDFs for burned and unburned pixels
Assign prior burned probability to each pixel
Bayesian classifier + supplementary relative threshold tests
43. Current Implementation Code written in C
Stand alone, non-ECS version
SDP Toolkit, PCFs, run-time environment variables not required
Moderate pig
I/O considerable
Map one month of one MODIS tile in ~2 hours
~300 MB semi-adjustable memory footprint
44. Current Input Requirements Daily gridded surface (or corrected) reflectance
Bands 1, 2, 5, and 7
Terra and/or Aqua MODIS
Reads MOD09GHK and MODHDFSR directly
Corrected reflectance ingest partially implemented
Daily gridded active fire maps
Preferably Terra + Aqua MODIS
Other sensors
Land cover map
MODIS MOD12Q1 by default but regional even better
All input data coregistered in MODIS sinusoidal projection
45. Short-Term MODIS Direct Readout Implementation Delayed production
Cumulative burn scar map through day N available on day N + ~15
Comparable quality to the official MODIS burned area product
Handle standard Direct Broadcast input data format(s)
define standard format or formats
Substantial data staging requirements
In practice need M + 2 months of daily data on disk to generate M-month map
46. Long-Term MODIS Direct Readout Implementation Rapid production
Cumulative map through day N available on day N
Map is refined as additional days are acquired
Minimal staging requirements
~10-day moving archive
Large reduction in I/O