NOAA NESDIS CENTER for SATELLITE APPLICATIONS and RESEARCH GOES-R Advanced Baseline Imager (ABI) Algorithm Theoretical Basis Document For Fire / Hot Spot Characterization Christopher C. Schmidt, UW-Madison SSEC/CIMSS Jay Hoffman, UW-Madison SSEC/CIMSS Elaine Prins, UW-Madison SSEC/CIMSS - Consultant Scott Lindstrom, UW-Madison SSEC Version 2.6 October 11, 2013 2 TABLE OF CONTENTS Page LIST OF FIGURES .......................................................................................................... V LIST OF TABLES ......................................................................................................... VIII LIST OF ACRONYMS .................................................................................................... IX ABSTRACT .................................................................................................................... XI 1 INTRODUCTION ...................................................................................................... 1 1.1 Purpose of This Document................................................................................ 1 1.2 Who Should Use This Document ...................................................................... 1 1.3 Inside Each Section .......................................................................................... 1 1.4 Related Documents .......................................................................................... 2 1.5 Revision History ................................................................................................ 2 2 OBSERVING SYSTEM OVERVIEW ........................................................................ 4 2.1 Products Generated .......................................................................................... 5 2.2 Instrument Characteristics ................................................................................ 6 3 ALGORITHM DESCRIPTION .................................................................................. 9 3.1 Algorithm Overview ........................................................................................... 9 3.2 Processing Outline .......................................................................................... 11 3.2.1 Loop over all pixels, aka Part I ................................................................. 13 3.2.2 Loop over all fire pixels, aka Part II .......................................................... 13 3.3.1 Primary Sensor Data................................................................................ 14 3.3.2 Ancillary Data ........................................................................................... 14 3.3.3 Derived Data ............................................................................................ 15 3.4 Theoretical Description ................................................................................... 16 3.4.1 Physics of the Problem ............................................................................ 16 3.4.2 Mathematical Description ......................................................................... 18 3.4.2.1 Input ABI and ancillary data ................................................................ 19 3.4.2.2 Calculate radiance differences ............................................................ 20 3.4.2.3 Test data against thresholds ............................................................... 20 3.4.2.4 Along scan reflectivity test ................................................................... 22 3.4.2.5 Determine background condition statistics .......................................... 23 3.4.2.6 Determine contextual thresholds ......................................................... 26 3.4.2.7 Apply thresholds to identify fire pixels ................................................. 27 3.4.2.8 Apply corrections and adjustments ..................................................... 28 3.4.2.9 Post corrections tests .......................................................................... 30 3.4.2.10 Sub-pixel characterization: Dozier .................................................... 31 3.4.2.11 Last chance fire tests ........................................................................ 35 3.4.2.12 Sub-pixel characterization: FRP ....................................................... 36 3.4.2.13 End part I .......................................................................................... 36 3.4.2.14 Start Part II: Threshold test ............................................................... 38 3.4.2.15 Determine fire category .................................................................... 39 3.4.2.16 Temporal filtering .............................................................................. 41 iii 3.4.2.17 Fire Output ........................................................................................ 41 3.4.2.18 End Part II ......................................................................................... 41 3.4.3 Algorithm Output ...................................................................................... 41 4 TEST DATA SETS AND OUTPUTS ...................................................................... 45 4.1 Simulated Input Data Sets .............................................................................. 45 4.2 Output from Simulated Inputs Data Sets ......................................................... 47 4.2.1 Precision and Accuracy Estimates ........................................................... 56 4.2.2 Error Budget ............................................................................................ 81 5 PRACTICAL CONSIDERATIONS .......................................................................... 83 5.1 Numerical Computation Considerations .......................................................... 83 5.2 Programming and Procedural Considerations ................................................ 83 5.3 Quality Assessment and Diagnostics .............................................................. 84 5.4 Exception Handling ......................................................................................... 84 5.5 Algorithm Validation ........................................................................................ 84 6 ASSUMPTIONS AND LIMITATIONS ..................................................................... 86 6.1 Performance ................................................................................................... 86 6.2 Assumed Sensor Performance ....................................................................... 88 6.3 Pre-Planned Product Improvements ............................................................... 89 REFERENCES .............................................................................................................. 90 APPENDIX 1: COMMON ANCILLARY DATA SETS ..................................................... 94 1. COAST_MASK_NASA_1KM .............................................................................. 94 a. Data description .............................................................................................. 94 b. Interpolation description .................................................................................. 94 2. DESERT_MASK_CALCLTED ............................................................................ 94 a. Data description .............................................................................................. 94 b. Interpolation description .................................................................................. 94 3. LAND_MASK_NASA_1KM ................................................................................. 95 a. Data description .............................................................................................. 95 b. Interpolation description .................................................................................. 95 4. NWP_GFS .......................................................................................................... 95 a. Data description .............................................................................................. 95 b. Interpolation description .................................................................................. 95 5. SFC_EMISS_SEEBOR ...................................................................................... 97 a. Data description .............................................................................................. 97 b. Interpolation description .................................................................................. 97 6. SFC_TYPE_AVHRR_1KM ................................................................................. 97 a. Data description .............................................................................................. 97 b. Interpolation description .................................................................................. 97 iv LIST OF FIGURES Page Figure 2.1 IR band spectrums for GOES-R ABI, MSG SEVIRI, GOES-8 and GOES- 12. The primary long-wave and short-wave IR window bands used for fire monitoring are circled in green and red, respectively. ............................................................................. 7 Figure 3.1 Products and dependencies of the land algorithm module. ..................... 10 Figure 3.2 High Level Flowchart of the ABI WF_ABBA fire code illustrating the main processing sections. .....................................................................................................