Satellite Fire Data Products - Revision history

Jmandel at 13:10, 27 August 2025

2025-08-27T13:10:01Z

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			[[Category:Data]]

	== Satellite Fire Data Products ==		== Satellite Fire Data Products ==

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2025-08-27T05:53:13Z

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2025-08-27T05:51:20Z

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Jmandel: from ChatGPT 5. Prompt: Provide a technical explanation of fire data products from satellites, particularly MODIS, VIIRS, GOES, with focus on Level 2 Active Fires data, concept of swath, granules, pixels, their numerical values, revisits, orbit design. Summarize differences between Level 1, 2 and 3 data. Approach: practical, for someone who needs to use and understand the data. Provide original references with links. Provide as a file for a simple wikimedia instal.

2025-08-27T01:42:28Z

from ChatGPT 5. Prompt: Provide a technical explanation of fire data products from satellites, particularly MODIS, VIIRS, GOES, with focus on Level 2 Active Fires data, concept of swath, granules, pixels, their numerical values, revisits, orbit design. Summarize differences between Level 1, 2 and 3 data. Approach: practical, for someone who needs to use and understand the data. Provide original references with links. Provide as a file for a simple wikimedia instal.

New page

== Satellite Fire Data Products ==

This page summarizes the main satellite fire data products from MODIS, VIIRS, and GOES, with focus on Level 2 Active Fires. The goal is practical: to understand what the data contain, how they are structured, and how to use them.

=== Processing Levels ===

* **Level 1 (L1B)**: Calibrated, geolocated radiances at native resolution.
* **Level 2 (L2)**: Derived geophysical variables at the same resolution as L1 (e.g., fire masks, Fire Radiative Power).
* **Level 3 (L3)**: Gridded or time-composited variables on standard grids (e.g., daily fire counts per 0.25° cell).

=== Key Geometry Terms ===

* **Swath**: The cross-track stripe observed as the sensor scans.
* **Granule**: The basic time chunk of data (e.g., 5–6 minutes for polar orbiters; 1–10 minutes for GOES sectors).
* **Pixel**: One sample from the sensor. Pixel size depends on instrument and grows off-nadir. VIIRS mitigates this with aggregation and "bow-tie deletion."

=== MODIS Active Fires (Terra and Aqua) ===

* **Satellites**: Terra (morning \~10:30, drifting earlier), Aqua (afternoon \~13:30).
* **Orbit**: Sun-synchronous near-polar, \~705 km altitude.
* **Swath and granules**: 2330 km wide swath, \~5 min granules.
* **Resolution**: 1 km at nadir, coarser off-nadir.
* **Products**: MOD14 (Terra), MYD14 (Aqua).
* **Fields**: Fire mask (low/nominal/high confidence), confidence 0–100%, FRP (MW), brightness temperatures, view geometry.
* **Revisit**: Two daily looks at mid-latitudes from both satellites combined.

=== VIIRS Active Fires (S-NPP, NOAA-20, NOAA-21) ===

* **Satellites**: Three polar orbiters in the JPSS constellation.
* **Orbit**: \~824 km altitude, \~13:30 LT ascending node.
* **Swath and granules**: 3060 km swath, 6 min granules.
* **Resolution**: 375 m (I-band), 750 m (M-band).
* **Products**: VNP14IMG (S-NPP), VJ114IMG (NOAA-20), VJ214IMG (NOAA-21).
* **Fields**: Fire mask, confidence %, FRP (MW), brightness temps, geometry.
* **Revisit**: Multiple looks/day, with \~25–50 min spacing between satellites. Both day (\~13:30) and night (\~01:30) coverage.

=== GOES ABI Fire/Hot Spot Products ===

* **Satellites**: GOES-East (GOES-19), GOES-West (GOES-18).
* **Orbit**: Geostationary at \~35,786 km.
* **Resolution**: 2 km at nadir for IR band 7 (3.9 µm).
* **Cadence**: 10 min full disk, 5 min CONUS, 1 min mesoscale.
* **Product**: Fire/Hot Spot Characterization (FHS/FDC).
* **Fields**: Fire mask codes (10/30 high confidence, 11/31 saturated, 12/32 cloud-contaminated, 13–15/33–35 lower probabilities), FRP (MW).
* **Notes**: Use mask codes 10,11,30,31 for conservative detection. Pixel locations not terrain-corrected, so offsets over mountains occur.

=== Complementarity ===

* **MODIS**: Coarser (1 km) but long record since 2000; provides morning and afternoon views.
* **VIIRS**: Finer (375 m), more frequent coverage with three satellites.
* **GOES**: Coarser (2 km) but provides rapid updates (1–10 min), enabling near-real-time fire behavior monitoring.

=== Practical Usage Tips ===

* Filter by confidence: MODIS/VIIRS high-confidence or ≥80%; GOES codes 10,11,30,31.
* Account for off-nadir pixel growth and location errors.
* Match granule timing to incident timelines (5 min MODIS, 6 min VIIRS, 1–10 min GOES).
* FRP is in MW per pixel, but uncertainty varies (higher for GOES lower-confidence classes).

=== References ===

* MODIS Active Fire Product (Collection 6.1): [https://lpdaac.usgs.gov/products/mod14v061/](https://lpdaac.usgs.gov/products/mod14v061/)
* VIIRS 375 m Active Fire Product: [https://lpdaac.usgs.gov/products/vnp14imgv001/](https://lpdaac.usgs.gov/products/vnp14imgv001/)
* VIIRS Algorithm Theoretical Basis Document: [https://lpdaac.usgs.gov/documents/197/VNP14\_User\_Guide\_V1.pdf](https://lpdaac.usgs.gov/documents/197/VNP14_User_Guide_V1.pdf)
* GOES ABI Fire/Hot Spot Characterization: [https://www.ospo.noaa.gov/Products/atmosphere/fire/](https://www.ospo.noaa.gov/Products/atmosphere/fire/)
* NASA EOSDIS Data Processing Levels: [https://earthdata.nasa.gov/faq/data-processing-levels](https://earthdata.nasa.gov/faq/data-processing-levels)

← Older revision		Revision as of 05:53, 27 August 2025
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	=== MODIS Active Fires (Terra and Aqua) ===		=== MODIS Active Fires (Terra and Aqua) ===

	* Satellites: Terra (morning \~10:30, drifting earlier), Aqua (afternoon \~13:30).		* Satellites: Terra (morning ~10:30, drifting earlier), Aqua (afternoon \~13:30).
	* Orbit: Sun-synchronous near-polar, \~705 km altitude.		* Orbit: Sun-synchronous near-polar, ~705 km altitude.
	* Swath and granules: 2330 km wide swath, \~5 min granules.		* Swath and granules: 2330 km wide swath, ~5 min granules.
	* Resolution: 1 km at nadir, coarser off-nadir.		* Resolution: 1 km at nadir, coarser off-nadir.
	* Products: MOD14 (Terra), MYD14 (Aqua).		* Products: MOD14 (Terra), MYD14 (Aqua).
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	* Satellites: Three polar orbiters in the JPSS constellation.		* Satellites: Three polar orbiters in the JPSS constellation.
	* Orbit: \~824 km altitude, \~13:30 LT ascending node.		* Orbit: ~824 km altitude, ~13:30 LT ascending node.
	* Swath and granules: 3060 km swath, 6 min granules.		* Swath and granules: 3060 km swath, 6 min granules.
	* Resolution: 375 m (I-band), 750 m (M-band).		* Resolution: 375 m (I-band), 750 m (M-band).
	* Products: VNP14IMG (S-NPP), VJ114IMG (NOAA-20), VJ214IMG (NOAA-21).		* Products: VNP14IMG (S-NPP), VJ114IMG (NOAA-20), VJ214IMG (NOAA-21).
	* Fields: Fire mask, confidence %, FRP (MW), brightness temps, geometry.		* Fields: Fire mask, confidence %, FRP (MW), brightness temps, geometry.
	* Revisit: Multiple looks/day, with \~25–50 min spacing between satellites. Both day (\~13:30) and night (\~01:30) coverage.		* Revisit: Multiple looks/day, with ~25–50 min spacing between satellites. Both day (~13:30) and night (~01:30) coverage.

	=== GOES ABI Fire/Hot Spot Products ===		=== GOES ABI Fire/Hot Spot Products ===

	* Satellites: GOES-East (GOES-19), GOES-West (GOES-18).		* Satellites: GOES-East (GOES-19), GOES-West (GOES-18).
	* Orbit: Geostationary at \~35,786 km.		* Orbit: Geostationary at ~35,786 km.
	* Resolution: 2 km at nadir for IR band 7 (3.9 µm).		* Resolution: 2 km at nadir for IR band 7 (3.9 µm).
	* Cadence: 10 min full disk, 5 min CONUS, 1 min mesoscale.		* Cadence: 10 min full disk, 5 min CONUS, 1 min mesoscale.

← Older revision		Revision as of 05:51, 27 August 2025
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	=== Processing Levels ===		=== Processing Levels ===

	~~* ~~Level 1 (L1B)**: Calibrated, geolocated radiances at native resolution.		* Level 1 (L1B): Calibrated, geolocated radiances at native resolution.
	~~* ~~Level 2 (L2)**: Derived geophysical variables at the same resolution as L1 (e.g., fire masks, Fire Radiative Power).		* Level 2 (L2): Derived geophysical variables at the same resolution as L1 (e.g., fire masks, Fire Radiative Power).
	~~* ~~Level 3 (L3)**: Gridded or time-composited variables on standard grids (e.g., daily fire counts per 0.25° cell).		* Level 3 (L3): Gridded or time-composited variables on standard grids (e.g., daily fire counts per 0.25° cell).

	=== Key Geometry Terms ===		=== Key Geometry Terms ===

	~~* ~~Swath**: The cross-track stripe observed as the sensor scans.		* Swath: The cross-track stripe observed as the sensor scans.
	~~* ~~Granule**: The basic time chunk of data (e.g., 5–6 minutes for polar orbiters; 1–10 minutes for GOES sectors).		* Granule: The basic time chunk of data (e.g., 5–6 minutes for polar orbiters; 1–10 minutes for GOES sectors).
	~~* ~~Pixel**: One sample from the sensor. Pixel size depends on instrument and grows off-nadir. VIIRS mitigates this with aggregation and "bow-tie deletion."		* Pixel: One sample from the sensor. Pixel size depends on instrument and grows off-nadir. VIIRS mitigates this with aggregation and "bow-tie deletion."

	=== MODIS Active Fires (Terra and Aqua) ===		=== MODIS Active Fires (Terra and Aqua) ===

	~~* ~~Satellites**: Terra (morning \~10:30, drifting earlier), Aqua (afternoon \~13:30).		* Satellites: Terra (morning \~10:30, drifting earlier), Aqua (afternoon \~13:30).
	~~* ~~Orbit**: Sun-synchronous near-polar, \~705 km altitude.		* Orbit: Sun-synchronous near-polar, \~705 km altitude.
	~~* ~~Swath and granules**: 2330 km wide swath, \~5 min granules.		* Swath and granules: 2330 km wide swath, \~5 min granules.
	~~* ~~Resolution**: 1 km at nadir, coarser off-nadir.		* Resolution: 1 km at nadir, coarser off-nadir.
	~~* ~~Products**: MOD14 (Terra), MYD14 (Aqua).		* Products: MOD14 (Terra), MYD14 (Aqua).
	~~* ~~Fields**: Fire mask (low/nominal/high confidence), confidence 0–100%, FRP (MW), brightness temperatures, view geometry.		* Fields: Fire mask (low/nominal/high confidence), confidence 0–100%, FRP (MW), brightness temperatures, view geometry.
	~~* ~~Revisit**: Two daily looks at mid-latitudes from both satellites combined.		* Revisit: Two daily looks at mid-latitudes from both satellites combined.

	=== VIIRS Active Fires (S-NPP, NOAA-20, NOAA-21) ===		=== VIIRS Active Fires (S-NPP, NOAA-20, NOAA-21) ===

	~~* ~~Satellites**: Three polar orbiters in the JPSS constellation.		* Satellites: Three polar orbiters in the JPSS constellation.
	~~* ~~Orbit**: \~824 km altitude, \~13:30 LT ascending node.		* Orbit: \~824 km altitude, \~13:30 LT ascending node.
	~~* ~~Swath and granules**: 3060 km swath, 6 min granules.		* Swath and granules: 3060 km swath, 6 min granules.
	~~* ~~Resolution**: 375 m (I-band), 750 m (M-band).		* Resolution: 375 m (I-band), 750 m (M-band).
	~~* ~~Products**: VNP14IMG (S-NPP), VJ114IMG (NOAA-20), VJ214IMG (NOAA-21).		* Products: VNP14IMG (S-NPP), VJ114IMG (NOAA-20), VJ214IMG (NOAA-21).
	~~* ~~Fields**: Fire mask, confidence %, FRP (MW), brightness temps, geometry.		* Fields: Fire mask, confidence %, FRP (MW), brightness temps, geometry.
	~~* ~~Revisit**: Multiple looks/day, with \~25–50 min spacing between satellites. Both day (\~13:30) and night (\~01:30) coverage.		* Revisit: Multiple looks/day, with \~25–50 min spacing between satellites. Both day (\~13:30) and night (\~01:30) coverage.

	=== GOES ABI Fire/Hot Spot Products ===		=== GOES ABI Fire/Hot Spot Products ===

	~~* ~~Satellites**: GOES-East (GOES-19), GOES-West (GOES-18).		* Satellites: GOES-East (GOES-19), GOES-West (GOES-18).
	~~* ~~Orbit**: Geostationary at \~35,786 km.		* Orbit: Geostationary at \~35,786 km.
	~~* ~~Resolution**: 2 km at nadir for IR band 7 (3.9 µm).		* Resolution: 2 km at nadir for IR band 7 (3.9 µm).
	~~* ~~Cadence**: 10 min full disk, 5 min CONUS, 1 min mesoscale.		* Cadence: 10 min full disk, 5 min CONUS, 1 min mesoscale.
	~~* ~~Product**: Fire/Hot Spot Characterization (FHS/FDC).		* Product: Fire/Hot Spot Characterization (FHS/FDC).
	~~* ~~Fields**: Fire mask codes (10/30 high confidence, 11/31 saturated, 12/32 cloud-contaminated, 13–15/33–35 lower probabilities), FRP (MW).		* Fields: Fire mask codes (10/30 high confidence, 11/31 saturated, 12/32 cloud-contaminated, 13–15/33–35 lower probabilities), FRP (MW).
	~~* ~~Notes**: Use mask codes 10,11,30,31 for conservative detection. Pixel locations not terrain-corrected, so offsets over mountains occur.		* Notes: Use mask codes 10,11,30,31 for conservative detection. Pixel locations not terrain-corrected, so offsets over mountains occur.

	=== Complementarity ===		=== Complementarity ===

	~~* ~~MODIS**: Coarser (1 km) but long record since 2000; provides morning and afternoon views.		* MODIS: Coarser (1 km) but long record since 2000; provides morning and afternoon views.
	~~* ~~VIIRS**: Finer (375 m), more frequent coverage with three satellites.		* VIIRS: Finer (375 m), more frequent coverage with three satellites.
	~~* ~~GOES**: Coarser (2 km) but provides rapid updates (1–10 min), enabling near-real-time fire behavior monitoring.		* GOES: Coarser (2 km) but provides rapid updates (1–10 min), enabling near-real-time fire behavior monitoring.

	=== Practical Usage Tips ===		=== Practical Usage Tips ===