Short Name: VNP14IMGTDL_NRT
Product Title: VIIRS (S-NPP) I Band 375 m Active Fire Product NRT (Vector data)
Links to Download Data: Active Fire Data
User Guide: VIIRS Active Fire User Guide
Long Name: VIIRS (S-NPP) I Band 375 m Active Fire locations NRT (Vector data) distributed by LANCE FIRMS
The near real-time (NRT) Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Active Fire detection product is based on that instrument's 375 m nominal resolution data. Compared to other coarser resolution (≥1 km) satellite fire detection products, the improved 375 m data provide greater response over fires of relatively small areas, as well as improved mapping of large fire perimeters. Consequently, the data are well suited for use in support of fire management (e.g., near real-time alert systems) as well as other science applications requiring improved fire mapping fidelity. The 375 m product complements the baseline Suomi NPP/VIIRS 750 m active fire detection and characterization data, which was originally designed to provide continuity to the existing 1 km Earth Observing System Moderate Resolution Imaging Spectroradiometer (EOS/MODIS) active fire data record. Due to frequent data saturation issues, the current 375 m fire product provides detection information only with no sub-pixel fire characterization.
VNP14IMGTDL_NRT data are available in the following formats: TXT, SHP, KML, WMS. These data are also provided through the LANCE FIRMS Fire Email Alerts. Please note only the TXT and SHP files contain all the attributes.
Spatial Resolution: 375 m
- Citation Policy and Disclaimer
- User Guide (updated July 2018)
- Metadata: Common Metadata Repository (CMR)
- For support, contact Earthdata Support
- Science Principal Investigator – Wilfrid Schroeder, NOAA
|Latitude||Latitude||Center of nominal 375 m fire pixel.|
|Longitude||Longitude||Center of nominal 375 m fire pixel.|
|Bright_ti4||Brightness temperature I-4||VIIRS I-4 channel brightness temperature of the fire pixel measured in Kelvin.|
|Scan||Along Scan pixel size||The algorithm produces approximately 375 m pixels at nadir. Scan and track reflect actual pixel size.|
|Track||Along Track pixel size||The algorithm produces approximately 375 m pixels at nadir. Scan and track reflect actual pixel size.|
|Acq_Date||Acquisition Date||Date of VIIRS acquisition.|
|Acq_Time||Acquisition Time||Time of acquisition/overpass of the satellite (in UTC).|
|Satellite||Satellite||N= Suomi National Polar-orbiting Partnership (Suomi NPP).|
This value is based on a collection of intermediate algorithm quantities used in the detection process. It is intended to help users gauge the quality of individual hotspot/fire pixels. Confidence values are set to low, nominal, and high. Low confidence daytime fire pixels are typically associated with areas of Sun glint and lower relative temperature anomaly (<15 K) in the mid-infrared channel I4. Nominal confidence pixels are those free of potential Sun glint contamination during the day and marked by strong (>15 K) temperature anomaly in either day or nighttime data. High confidence fire pixels are associated with day or nighttime saturated pixels.
Please note: Low confidence nighttime pixels occur only over the geographic area extending from 11° E to 110° W and 7° N to 55° S. This area describes the region of influence of the South Atlantic Magnetic Anomaly which can cause spurious brightness temperatures in the mid-infrared channel I4 leading to potential false positive alarms. These have been removed from the NRT data distributed by FIRMS.
|Version||Version (collection and source)||
Version identifies the collection (e.g., VIIRS Collection 1 or VIIRS Collection 2), and source of data processing (Ultra Real-Time (URT suffix added to collection), Real-Time (RT suffix), Near Real-Time (NRT suffix) or Standard Processing (collection only). For example:
"2.0URT" - Collection 2 Ultra Real-Time processing.
|Bright_ti5||Brightness temperature I-5||I-5 Channel brightness temperature of the fire pixel measured in Kelvin.|
|FRP||Fire Radiative Power||
FRP depicts the pixel-integrated fire radiative power in megawatts (MW). Given the unique spatial and spectral resolution of the data, the VIIRS 375 m fire detection algorithm was customized and tuned to optimize its response over small fires while balancing the occurrence of false alarms. Frequent saturation of the mid-infrared I4 channel (3.55-3.93 µm) driving the detection of active fires requires additional tests and procedures to avoid pixel classification errors. As a result, sub-pixel fire characterization (e.g., fire radiative power [FRP] retrieval) is only viable across small and/or low-intensity fires. Systematic FRP retrievals are based on a hybrid approach combining 375 and 750 m data. In fact, starting in 2015 the algorithm incorporated additional VIIRS channel M13 (3.973-4.128 µm) 750 m data in both aggregated and unaggregated format.
|Type*||Inferred hot spot type||0 = presumed vegetation fire
1 = active volcano
2 = other static land source
3 = offshore detection (includes all detections over water)
|DayNight||Day or Night||
D= Daytime fire, N= Nighttime fire
*This attribute is only available for VNP14IMGT (standard quality) data
- Related Products
VECTOR DATA—available from LANCE FIRMS including data from MODIS Terra, MODIS Aqua, and VIIRS Suomi NPP
Data extracted from the VNP14IMGT Standard Active Fire / Thermal Anomalies product are available, usually after 2 months, from the FIRMS Active Fire Download Tool. The VNP14IMGT can be viewed in FIRMS Fire Map and Worldview. Temporal Coverage: 20 January 2012 to the present.
- VIIRS/Suomi NPP Active Fires 6-Min L2 Swath 375m NRT
- Climate Modeling Grid Fire Products
- VIIRS/Suomi NPP Thermal Anomalies/Fire 6-Min L2 Swath 750 m V001
- Data Acknowledgement
This dataset was provided by LANCE FIRMS operated by NASA ESDIS with funding provided by NASA Headquarters
For Shape Files:
- NASA Near Real-Time VNP14IMGTDL_NRT VIIRS 375 m Active Fire Detections (SHP format). Dataset. Available online [https://www.earthdata.nasa.gov/learn/find-data/near-real-time/firms/active-fire-data]
For Text Files:
- NASA Near Real-Time VNP14IMGTDL_NRT VIIRS 375 m Active Fire Detections (TXT format). Dataset. Available online [https://www.earthdata.nasa.gov/learn/find-data/near-real-time/firms/active-fire-data]
For KML Files:
- NASA Near Real-Time VNP14IMGTDL_NRT VIIRS 375 m Active Fire Detections (KML format). Dataset. Available online [https://www.earthdata.nasa.gov/learn/find-data/near-real-time/firms/active-fire-data]
For WMS Files:
- NASA Near Real-Time VNP14IMGTDL_NRT VIIRS 375 m Active Fire Detections (WMS format). Dataset. Available online [https://www.earthdata.nasa.gov/learn/find-data/near-real-time/firms/active-fire-data]
Schroeder, W., Oliva, P., Giglio, L., & Csiszar, I. A. (2014). The New VIIRS 375 m active fire detection data product: algorithm description and initial assessment. Remote Sensing of Environment, 143, 85-96. doi:10.1016/j.rse.2013.12.008 PDF
- Near Real-Time vs Standard Products
The VIIRS 375 m NRT products (VNP14IMGTDL_NRT) are produced in near real-time by NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) and may be subject to geolocation errors or reprocessing.
LANCE processes data as soon as they are downlinked from satellites or transmitted from ground stations, generally within 30 minutes to two hours after satellite observation. Routines used to derive Level 2 products, such as fire, snow, and sea ice products, do not make use of ancillary data and therefore their codes are identical to the ones used in standard operations.
Generally, the difference between NRT and standard products is that the NRT data are subject to geolocation errors or reprocessing. Usually the geolocational errors are minimal (less than 100 meters); however, there are situations, particularly before and after spacecraft maneuvers and during space weather events, when the difference can increase up to several kilometers.
- Known Issues
To be updated
- Further Reading
- VIIRS 375 m I Band Active Fire Product
- VIIRS 375 m Active Fire Algorithm User Guide (updated July 2018)
- University of Maryland VIIRS Active Fire Web page