VJ114IMGTDL_NRT

Short Name: VJ114IMGTDL_NRT

Product Title: VIIRS (NOAA-20/JPSS-1) I Band 375 m Active Fire Product NRT (Vector data)

DOI: 10.5067/FIRMS/VIIRS/VJ114IMGT_NRT.002

Links to Download Data: Active Fire Data

User Guide: VIIRS Active Fire User Guide

Long Name: VIIRS (NOAA-20/JPSS-1) I Band 375 m Active Fire locations NRT (Vector data) distributed by LANCE FIRMS

View in map interface: FIRMS Global or FIRMS US/Canada

Summary

Near real-time (NRT) NOAA-20 (formally JPSS-1) Visible Infrared Imaging Radiometer Suite (VIIRS) Active Fire detection product is based on the instrument's 375 m nominal resolution data. Compared to other coarser resolution (≥1km) 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.

VJ114IMGTDL_NRT are available in the following formats: TXT, SHP, KML, and 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.

Coverage: Global
Spatial Resolution: 375 m
Projection: WGS84

Attribute Fields

Attribute
Short Description
Long Description
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), N20= NOAA-20 (formally JPSS-1), N21= NOAA-21 (formally JPSS-2)
Confidence Confidence

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 (<15K) in the mid-infrared channel I4. Nominal confidence pixels are those free of potential sun glint contamination during the day and marked by strong (>15K) 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)

"2.0URT" - Collection 2 Ultra Real-Time processing
"2.0RT" - Collection 2 Real-Time processing
"1.0NRT" - Collection 1 NRT processing
"1.0" - Collection 1 Standard 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 MW (megawatts). Given the unique spatial and spectral resolution of the data, the VIIRS 375 m fire detection algorithm was customized and tuned in order 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 standard quality (not NRT) data 

Related Products

VECTOR DATA—available from LANCE FIRMS

Data extracted from the VJ114IMGT Standard Active Fire / Thermal Anomalies product are available, usually after 2 months, from the FIRMS Active Fire Download Tool. The VJ114IMGT can be viewed in FIRMS Fire Map and Worldview. Temporal Coverage: 20 January 2012 to the present.

RASTER DATA

NEAR REAL-TIME L2 PRODUCTS (HDF-EOS format)—available from LANCE, Earthdata Search, and LAADS DAAC

  • VIIRS/NOAA-20 Active Fires 6-Min L2 Swath 375m NRT
  • Climate Modeling Grid Fire Products

STANDARD SCIENCE QUALITY PRODUCTS—available from LAADS DAAC and Earthdata Search

  • VIIRS/Suomi NPP Thermal Anomalies/Fire 6-Min L2 Swath 750m V001
Data Acknowledgement

This data set 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). Data set. Available online [/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). Data set. Available online [/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). Data set. Available online [/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). Data set. Available online [/learn/find-data/near-real-time/firms/active-fire-data]

Data Citation

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) produced in near real-time by the Land, Atmosphere Near real-time Capability for EO (LANCE) and may be subject to geo-location errors or re-processing.

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

General Information

Last Updated