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Overview
Content Tools
- New Near Real-Time Product in FIRMS – Landsat Active Fire Data – October 2022
- Characteristics of VIIRS, MODIS and OLI Sensors and Their Effects on the Spatial Extent of Daily Active Fire Data – September 2022
- New Enhancements Make Generating Imagery Subsets in Worldview Snapshots Even Easier – October 2022
- Landsat 9 Now Included in Harmonized Landsat/Sentinel-2 Imagery – August 2023
- How to customize the fires displayed in FIRMS – July 2022
- Wildfire detection in the US and Canada within a minute of satellite observation – July 2022
- New - GeoTIFF from FIRMS Screenshot – July 2022
- New - Harmonized Landsat/Sentinel-2 Imagery (beta version) – April 2022
- New FIRMS Feature / Location Tool – January 2022
- Basic and Advanced Modes for FIRMS Users – August 2021
- Where’s the smoke coming from? – July 2021
- Additional information about wildland fires in US and Canada – July 2021
- New FIRMS Feature/Capability Highlight – June 2021
- New Web Services added to FIRMS US/Canada and FIRMS Global – June 2021
- FIRMS US/Canada Prototype Released – January 2021
NASA Earthdata Articles on FIRMS
The Big and Small of Fire in Africa
Landsat Fire and Thermal Anomaly Data Added to FIRMS
FIRMS Adds Ultra Real-Time Data from MODIS and VIIRS
New HLS False Color Composite Layer Added to FIRMS
NASA, Forest Service Partnership Expands Active Fire Mapping Capabilities
Wildfires Can't Hide from Earth Observing Satellites
NASA FIRMS Helps Fight Wildland Fires in Near Real-Time
Earlier this year, we highlighted the availability of Landsat 8 and Landsat 9 Operational Land Imager (OLI) imagery in the FIRMS map viewers. This imagery, provided by NASA's IMPACT project, enables a relatively high spatial resolution perspective of fire activity and post-fire effects. Similar to MODIS and VIIRS, we are now providing active fire data in FIRMS, generated from Landsat observations.
This new near real-time (NRT) Landsat Fire and Thermal Anomaly (LFTA) active fire product is the result of an ongoing collaboration by NASA LANCE/FIRMS, University of Maryland, USDA Forest Service and USGS EROS Data Center. The total elapsed time from satellite overpass to the availability of Landsat active fire detection data in FIRMS is 30 minutes or less. Users should note that these Landsat active fire detection data are provided much sooner than the Harmonized Landsat-Sentinel (HLS) imagery products, that are dynamically generated, and currently available in FIRMS approximately 2 days after acquisition.
Daily Landsat 8 and Landsat 9 OLI data for CONUS and most of Canada and Mexico are collected via direct readout by USGS EROS Data Center in Sioux Falls, South Dakota. At the request of NASA and the USDA Forest Service, USGS developed a near real-time data processing framework that provides Level 1 terrain corrected Landsat OLI imagery. This data is subsequently processed using NASA science data processing algorithms to generate Level 2 30 meter resolution active fire data.
How does Landsat active fire data compare with MODIS and VIIRS active fire data?
Landsat active fire data is more than 1,000 times more resolute than MODIS and more than 160 times more resolute than MODIS and VIIRS, respectively. The algorithm routinely detects fires as small as a few square meters, or smaller, providing spatially explicit detail of location and extent of fire activity at the time of satellite overpass. Active fire fronts, as well as scattered smaller fires within the fire perimeter are routinely detected. However, these relatively high spatial resolution data have a lower temporal resolution compared to the daily observation frequency afforded by MODIS and VIIRS. Between both Landsat OLI instruments, areas in the lower to mid latitudes are imaged every 8 days (please see the related NASA FIRMS blog entry that describes the characteristics of different satellite sensors and their effects on the spatial extent of daily active fire data). The temporal resolution of Landsat data can be increased though collection of nighttime Landsat 8 and Landsat 9 imagery for targeted areas when it can feasibly be done within the confines of current Landsat science and mission priorities.
Viewing the LFTA in FIRMS
The Landsat active fire data can be viewed in both FIRMS global and FIRMS US/Canada. The LFTA are displayed in Basic and Advanced Mode.
To display the Landsat active fire detections by time since detection, select the "Time Based" option.
To distinguish the Landsat active fire detections from other active fire detections (such as MODIS and VIIRS), select the "Advanced Mode" and "Custom" and select the "+" icon next to the fire detections you want to change. Select the drop down arrow to the right of the color and a color wheel will appear. Select a color and press apply.
For more information see the FIRMS blog entry on How to customize the fires displayed in FIRMS
A September 10, 2022 HLS Landsat 9 OLI false color composite image for the southern portion of the Double Creek Fire in northeast Oregon. In the top image, burned areas appear in dark red hues while both isolated and broadly burning areas appear bright orange-red. The bottom image highlights the 30-meter active fire detections (yellow) that correspond to actively burning areas. Users should note that Landsat active fire detection data is available in FIRMS in near real-time approximately 30 minutes after acquisition while corresponding Landsat imagery is generated dynamically and available in FIRMS 2-3 days after acquisition.
With most sources of satellite remote sensing data, spatial resolution and temporal resolution are inversely related. In other words, as spatial resolution increases, temporal resolution decreases and vice versa. For example, the VIIRS sensor onboard S-NPP and NOAA-20 has a swath width of 3,000 kilometers and each instrument images the entire surface of the Earth at least once daily. The swath width of MODIS onboard Terra and Aqua is narrower at 2,330 km providing slightly less than daily global coverage. However, the finest spatial resolution of active fire detection data that can be gleaned from VIIRS and MODIS at 375 meters and 1 kilometer, respectively, are considered coarse resolution data by most definitions.
In comparison to VIIRS and MODIS, the Operational Land Imager (OLI) onboard both Landsat 8 and Landsat 9 provides active fire detections at relatively finer spatial resolution (30 meters) (please see the related NASA FIRMS blog entry that introduces the Landsat active fire product). Unlike VIIRS and MODIS, OLI has a much narrower swath width of 185 kilometers. The swath of OLI is less than 1/10th the width of a MODIS swath and provides much lower temporal resolution/sampling by comparison (Fig 1).
Figure 1 - Example of a 185 km Landsat 9 OLI swath (red) compared to a 2,330 km Terra MODIS swath (orange). Terra MODIS can easily image the entire continental US daily in three consecutive orbits. However, Landsat 8 and Landsat 9 OLI each require multiple orbits over 16 days to provide the same coverage.
How do these characteristics affect the daily availability of active fire data?
The relatively large swath widths of VIIRS and MODIS sensors provide comprehensive satellite observations and derived active fire detection data for the entire globe on a daily basis. Additionally, both sensors provide multiple observations daily within a relatively short period of time where consecutive swaths may overlap, more so at higher latitudes (Fig 2).
Figure 2 - Example of MODIS and VIIRS orbit tracks showing overlap between tracks, especially at higher latitudes.
Conversely, each Landsat OLI sensor requires 16 days to completely image the surface of the Earth. So, OLI cannot fully image large geographic areas in one day, such as the continental United States, and can only provide partial coverage. However, since the orbits of the two Landsat satellites are 8 days out of phase, the combined temporal resolution of the two OLI sensors enables complete coverage once every 8 days (Fig 3).
Figure 3 – The top graphic provides an example of the swath coverage for the continental US by OLI onboard Landsat 8 (orange) and Landsat 9 (red) on July 13, 2022. Orbits for each satellite move to the east and west daily and complete a full cycle of coverage every 16 days. The bottom graphic displays the HLS imagery product in FIRMS for July 13, 2022, which contains the acquired Landsat 8 and Landsat 9 imagery over land. Areas along each swath that exceed the predetermined cloud cover threshold are excluded from HLS product in FIRMS. The combined daily coverage of OLI on both Landsat satellites can image the entire continental US, and the globe, every 8 days.
When viewing daily active fire detection data in FIRMS, users should be aware of the high temporal resolution characteristics of VIIRS and MODIS versus Landsat. In Figure 4, active fires detected by Terra MODIS and Landsat on September 10, 2022, for the Pacific Northwest are provided. Landsat active fire detection data, displayed as yellow points, is only available within the 185-kilometer OLI swath. However, MODIS active fire detection data, displayed as red points, is available for the entire region within and outside of the OLI swath. Consequently, updates to the finer resolution Landsat active fire detection data for the entire Earth cannot be provided daily.
Figure 4 - Active fires detected in the Pacific Northwest on September 10, 2022. 1 kilometer MODIS active fire detections (red) are available for the entire region while 30-meter Landsat 9 active fire detections (yellow) are limited to the 185-kilometer swath (WRS-2 Path 42) acquired on this date.
The NASA Worldview Snapshots tool enables users to easily create satellite imagery subsets for anywhere in the world. The tool provides access to current and historical imagery captured by Terra and Aqua MODIS and S-NPP and NOAA-20 VIIRS. By simply selecting the desired image product, acquisition date, spatial resolution, output file type as well as entering the latitude/longitude bounding box, users can quickly generate an imagery subset to use for visualization in a GIS or as a graphic in a presentation or document.
For the convenience of users who need to create satellite imagery subsets of geopolitical units, Snapshots has recently been enhanced to include predefined latitude/longitude bounding boxes for countries. After setting the basic parameters for an imagery subset, users can simply select their desired country of interest from the Countries dropdown list in Country/Region Presets box below the map. The red box that subsequently appears on the map indicates the bounding box of the subset to be generated. Users can also increase the default size of the subset boundary extent by 5% to 20% by selecting the desired 5% interval under the Padding dropdown list or manually edit the predefined coordinates as desired in the Bounding Box section of the interface.
Users can also generate imagery subsets for a US state or Canadian province or territory. After selecting either of these two countries, a user can select the State / Province / Region dropdown list to update the subset bounding box extent to the targeted state, province or territory.
A September 9, 2022 Aqua MODIS true color composite image for Oregon generated from NASA Worldview Snapshots. The subset bounding box is defined by the map extent of the state, predefined in Snapshots, and extended by an additional 5% in both dimensions.
A screenshot of the Worldview Snapshots definition for an imagery subset of the state or Oregon. The updated interface enables users to select a country (as well as a US state and Canadian province/territory) and use its associated map extent as the bounding box coordinates for the subset boundary. If desired, users can increase the size of the predefined bounding box in 5% intervals or edit manually edit the coordinates.
Earlier this year, FIRMS integrated the Harmonized Landsat/Sentinel-2 (HLS) Imagery product. This data stream has recently been enhanced with the integration of Landsat 9 data. Users can now integrate HLS True Color and False Color Composite Imagery from Landsat 9 in addition to Landsat 8. Both Landsat instruments image every location on the Earth's surface at least every 16 days and their respective orbits are 8 days out of phase. As a result, they provide 8 day repeat coverage of any area on the globe. With the two Landsat instruments and two Sentinel-2 instruments, the HLS data stream allows for 30 meter land surface observations every 2-3 days.
HLS data services are made available by the NASA Interagency Implementation and Advanced Concepts Team (IMPACT) and can be visualized in FIRMS map viewers approximately 2-4 days after acquisition. Please see the April 2022 FIRMS blog post for additional information on the HLS data product and how to access it in FIRMS.
HLS false color composite image for the Moose Fire in northeast Idaho acquired by Landsat 8 on July 18, 2022 (top). The HLS false color image acquired on July 26, 2022 by Landsat 9 (bottom) illustrates the growth of the fire over that 8 day period. Note active fire areas in these images appear as glowing orange.
This blog shows you how to:
- change the colors of the fires/thermal anomalies
- change the fire pixel size
- show only day or night detections
- color code fires by Fire Radiative Power (FRP), Confidence or Time Since Detection
CHANGE FIRE COLOR BY INSTRUMENT
The default color for the MODIS and VIIRS thermal anomalies is red. There are times when it is useful to be able to distinguish between instruments (MODIS/VIIRS) or day/night detections. To do this Select ADVANCED MODE in the Layer List on the right of the map (see image below)
Select the "+" icon next to the fire detections you want to change.
Select the drop down arrow to the right of the color and a color wheel will appear. Select a color and press apply.
This step can be repeated for other fire detection categories.
CHANGE FIRE PIXEL SIZE
The fire pixel size defaults to the optimal display for the zoom level. When zoomed into the highest zoom levels, MODIS pixels maintain a size of approximately 1km and VIIRS approximately 375m
To change the pixel size, make sure ADVANCED MODE is selected (as shown above). Click the "+" icon and then click the drop down arrow next to the word "Auto"
Adjust the pixel size from the drop down list
SHOW ONLY DAY / NIGHT FIRES
By default, the map shows both Day time and night time fires, to view only day time fires, may sure ADVANCED MODE is selected (as shown above). Click the "+" icon then click on "Night" to deselect it and it is greyed out. To view only nighttime fires, click on "Night" to turn both back on and then click on "Day" so it is greyed out.
VIEW FIRES BY FRP, CONFIDENCE or TIME SINCE DETECTION
To view fires using Fire Radiative Power (FRP), Confidence or Time Since Detection, select "ADVANCED MODE" in the Layer List, then select the drop down arrow next to the word "Fires" for the fire detections you want to change.
Time Since Detection shows the fires < 1, 1-3, 3-6, 6-12, 12-24, and >24 Hours since the fires were detected by the satellite. Enable this by selecting "Time Based" in either Basic or Advanced Mode.
FIRMS recently integrated ultra real-time (URT) MODIS and VIIRS active fire data, within a minute of satellite observation, from multiple direct readout ground stations in the continental US (CONUS).
See "FIRMS Adds Ultra Real-Time Data from MODIS and VIIRS" article on Earthdata.nasa.gov
This is the first routine service provided by FIRMS for detecting wildfires over the continental United States from NASA and NOAA low-Earth orbit satellites with a latency of less than 60 seconds from Earth observation to wildfire detection. The ultra real-time processing has been made possible by the Space Science and Engineering Center (SSEC) at the University of Wisconsin-Madison with funding from NASA's WildFireSense program. Software systems enable the SSEC to stream direct broadcast data in real-time from each antenna to a central collection point at the University of Wisconsin–Madison, which then ingests and merges the data, including de-duplication of overlapping data, in real-time.
Currently URT data are received from Madison, Wisconsin (2 antennas), Hampton, Virginia and Mayaguez, Puerto Rico. In addition to the URT, Real-Time (RT) data are received from Honolulu, Hawaii and Monterey, California (after the pass is complete). Latency for RT data is 20—30 minutes. It is anticipated that the real-time data will be expanded to include additional CONUS stations and stations in Alaska and Hawaii.
Figure showing current and planned coverage of Direct Broadcast
stations collecting ultra real-time and real-time data
URT and RT thermal anomaly / fire detections are processed using the LANCE FIRMS active fire algorithms, so the data are comparable with the NRT data from LANCE.
- URT and RT data are available in both FIRMS and FIRMS US/Canada Fire maps and can be identified by the URT or RT suffix in the "version" - found by clicking on the fires to view the attributes.
- URT and RT data are also available in the WMS and WFS map services and KMZs.
- URT and RT data will roll off the system within six hours as the NRT data becomes available.
Screenshot showing URT fire detected on 2022/06/30.
The fire was observed at 12:17 CDT and displayed in FIRMS at 12:19 CDT
(as shown by computer time on top right of screen)
Users can see the real-time fire detections by selecting the Time Based option which color codes fires by Time Since Detection. However it is important to note that the URT and RT fires only show up within a minute of satellite fly-over so users need to know when the satellite passes overhead. To find our what time the satellite overpass is you can load the orbit tracks. (see next screenshot)
Screenshot showing descending overpass times from Suomi-NPP, NOAA-20, Aqua and Terra. These can be added by going to Advanced Mode and then selecting tracks from the Orbit Tracks and Overpass Times.
Once you have the Orbit tracks loaded, make sure the fires display using the "Time-Based" option and the look for the deep red colored squares.
FIRMS fire map users have always had the opportunity to compile a map view using desired layers and then capture a screenshot and save it as a JPG, PNG or GIF file to use or share. Users now have the option of capturing a FIRMS map view as a GeoTIFF image file. The GeoTIFF format includes spatial (georeferencing) information embedded in the .tif file so it can be integrated and viewed with other geospatial data. The GeoTIFF standard is in the public domain and can be readily imported and displayed in many GIS applications.
To create a GeoTIFF, click on the "screenshot" icon from the lower right of the FIRMS user interface and select "GeoTIFF" from the dropdown option in the screenshot window.
In collaboration with NASA's IMPACT project, dynamic false color imagery is now available through FIRMS to help better delineate burned areas.
A screenshot from FIRMS US/Canada displaying the Sentinel-2 Adjusted Reflectance Harmonized Landsat Sentinel (HLS) using bands 12-8a-4. It shows the Hermits Peak Fire in New Mexico, USA as captured on 3 May 2022. In this image, the burned areas appear in brick red and are overlain with active fire pixels from MODIS and VIIRS. (Link to view in FIRMS)
FIRMS has recently integrated an additional Harmonized Landsat/Sentinel-2 (HLS) Imagery product. The Reflectance (Bands 7-5-4) layer from Landsat 8/OLI and (Bands 12, 8a, 4) from Sentinel 2A and 2B are false color composite (FCC) images that allow us to visualize wavelengths that the human eye cannot see (i.e. short wave infrared and near infrared). Burned areas appear almost brick red making it easier to see fire affected areas and water is very dark, almost black, which makes it much easier to see lakes or flooded lands.
Unlike other satellite imagery layers in FIRMS, which are provided through NASA GIBS, the beta version HLS False Color Composite Imagery (Bands 7-5-4 for Landsat and Bands 12, 8a, 4 for Sentinel 2A and 2B), are provided dynamically through the NASA Interagency Implementation and Advanced Concepts Team (IMPACT), as such it may take slightly longer to display than the HLS True Color imagery through GIBS. HLS imagery is currently available approximately 2 -4 days after acquisition.
Steps to view the HLS FCC layers:
The HLS layers are only available in Advanced Mode (basic mode has reduced functionality to minimize the complexity of the interface).
• Go to https://firms.modaps.eosdis.nasa.gov/usfs/map/ or https://firms.modaps.eosdis.nasa.gov/map/
• Toggle the “Advanced Mode” button in the upper right .
• Toggle the “Historical” button in the upper right.
• The HLS Landsat and Sentinel 2 imagery are in the “Harmonized Landsat/Sentinel-2” grouping in the table of contents.
• Use the tools/prompts to access and view the imagery.
• Toggle on the True Color imagery first to get a good idea of where the FCC data can be expected on a given day.
Use the screenshot tool to create a GeoTIFF of the image to enable the image to be imported in to a GIS.
Some things to note:
• The HLS imagery is not near real-time data. It is currently available about 2 -4 days after acquisition.
• The reach back on this service goes back to March 15, 2022.
• As the FCC is dynamically generated, it may take slightly longer to display than the True Color imagery through GIBS. We are monitoring the performance of the HLS FCC imagery and welcome feedback.
• Zoom scale to display the false color composite data is currently set to 11 through 14, but true color can be viewed at smaller scales. The zoom level is indicated at the very end of the URL (e.g., 11z).
• Orbit tracks for Landsat 8 and Sentinel 2A and 2B are available as layers in the table of contents.
• Landsat 9 data is anticipated to be incorporated into the HLS product in late April. At that time, or soon thereafter, it will be part of the HLS service in FIRMS.
FIRMS recently added a location tool to enable users to easily find and save places of interest.
Open the Location Tool by clicking on the "Location" icon from the bottom menu of FIRMS Fire Map or the FIRMS US/Canada Fire Map.
- Enter the location or coordinates to search in the "Find Location" tab, checking the box to "allow multiple location selection".
- Click on the "Current Location" to find out what location you are viewing.
- Any locations you store for future visits will be saved under the "Saved Locations" tab.
Basic Mode
FIRMS provides a comprehensive array of near real-time NASA Earth observations and derived science data products to detect the location and extent of fire activity and its effects on the land and atmosphere. FIRMS has recently implemented a scalable user interface to better meet the needs and use cases of various users. When initiating the fire map for either FIRMS Global or FIRMS US/Canada FIRMS, the user interface to the right of the map window defaults to BASIC MODE. In this mode, a focused list of commonly used layers is presented to the user for display. This list includes MODIS and VIIRS active fire detection data, locations of current US and Canada large wildland fires, true color MODIS and VIIRS satellite imagery and particular background and overlay layers.
By simply selecting the button, users can choose to toggle to ADVANCED MODE. In this mode, all available FIRMS layers are provided for users to access and display. This includes false color MODIS and VIIRS satellite imagery, MODIS and VIIRS land and atmosphere science data products, additional sources of satellite imagery, contextual layers for wildland fire management, and several overlay and background layers.
As with other user-applied customizations to the fire map, when a bookmark is created, the map will retain the applied mode when you return to the map using that referenced bookmark.
FIRMS is continuing to add relevant sources of Earth observation data and science data products. Please stay tuned as we continue to introduce these additional sources of data and associated tools and utilities.
Advanced Mode
Viewing smoke in FIRMS using corrected reflectance imagery
Wildland fires can be a significant source of smoke that not only impairs our ability to enjoy clear vistas, but the gases and particulate matter it contains can be harmful to public health. When you see smoke in the sky it may be originating from a relatively local fire or a fire that is occurring several hundred miles away. True color composite imagery acquired by Terra MODIS, Aqua MODIS, S-NPP VIIRS or NOAA-20 VIIRS are provided as “Backgrounds” layers in FIRMS and FIRMS US/Canada Fire Maps. These layers display a "natural color image" of the Earth’s surface as it would look to the human eye from space. Consequently, it is easy to see smoke using this type of imagery in clear sky conditions. The time of observation for these four satellites occur at different times during the day, so they can be used to identify current sources of wildland fire smoke and visualize its transport across long distances. Use the Orbit Tracks and Overpass Times layers to determine the daily overpass time for each satellite.
Viewing smoke in FIRMS using aerosol indices
The standard Aerosol Index (AI) derived from S-NPP OMPS observations can also be used for identifying and tracking smoke as well as other aerosols. The OMPS Al, available as an “Overlays” layer in the FIRMS and FIRMS US/Canada Fire Maps, detects and measures the density of smoke and suspended particles in the vertical air column in the atmosphere. Typical values of the AI range from 0 to 5 and indicate dust storms or biomass burning smoke located in the lower troposphere (1-3 km). Values of 5.0 indicate heavy concentrations of aerosols that could reduce visibility or impact human health. For AI values significantly higher than 5 use the OMPS PyroCumuloNimbus, or pyroCb, AI layer. Larger pyroCb AI values between 5 and 10 usually indicate dense smoke from intensely burning fires that reach higher in the troposphere. Once the index gets above 10, the smoke has likely been produced from a pyroCb event, with dense smoke lofted into the upper troposphere and, often, into the stratosphere.
Wildland fire smoke visible in S-NPP VIIRS true color imagery acquired on July 11, 2021 (top). Active fire detections are displayed as red points. The aerosol index derived from S-NPP OMPS observations collected at the same time as the VIIRS imagery is provided for comparison (bottom). The high index values over Utah, Colorado, Wyoming and Montana indicate high concentrations of aerosols and are a result from fire activity in the Pacific Northwest and northern California. High aerosol index values in the eastern Dakotas, Minnesota and western Ontario are sourced from wildland fire activity in eastern Manitoba and western Ontario.
Get information and zoom to extent of wildland fires
The new FIRMS US/Canada fire map includes the location and details of wildland and prescribed fires. Locations of currently/recently active incidents larger than 100 acres (40.5 hectares) are displayed as fire icons when you open the US & Canada Fire Map. Click USA Active Fires and Canada Active Fires layers to toggle them off.
Click on a fire location to view the name, discovery date/time and current size of the fire. This information is routinely updated and maintained in systems of record managed by US and Canadian wildland fire management agencies. Clicking the View Situation Report link spawns a national situation report which may contain specific reporting information about the fire of interest. Additionally, by clicking the ZOOM TO LOCATION button, your map extent will automatically zoom to the extent of that fire.
Clicking on a fire location provides information about the fire and the option to zoom to the map extent of the selected fire.
Perimeters for current US wildland fires
For wildland fires currently occurring in the US larger than 100 acres in size, fire perimeters are provided for context. These data are typically compiled by federal, state and local fire management agencies on a routine basis during the life of an incident, however, they may not be available for all incidents. These data are typically updated daily from multiple sources and indicate the current extent of the fire and containment lines. Click on USA Fire Perimeter layer to display the fire perimeter data in the FIRMS US/Canada Fire Map.
When using perimeters in the context of satellite active fire detection data, this can indicate where a fire is active within the perimeter and if it is growing outside of it. Additionally, if the fire perimeter is not fully covered by cumulative active fire detections, gaps in that coverage may indicate where the fire has grown in between observations by polar-orbiting satellite sensors like MODIS and VIIRS, cloud cover at the time of satellite overpass occluded observations when the fire was actively burning, or fire activity was smaller and/or less intense at the time of satellite overpass or was not detectable under the vegetation canopy. Isolated active fire detection pixels outside of the perimeter can be indicative of detections occuring towards the edge of a swath which results geolocational errors due to the increasingly distorted field of view in the scan track direction, particularly for MODIS.
Visualization of MODIS and VIIRS active fire detection data in the context of a current perimeter for a wildland fire.
The FIRMS team has introduced several new features and capabilities to both FIRMS Global and FIRMS US/Canada. We’ll continue to highlight these new additions over several future posts.
In this post, we would like to highlight the Time Since Detection classification for MODIS and VIIRS active fire detection data that is available in the fire map for FIRMS Global and FIRMS US/Canada. This classification symbolizes active fires based on their time of detection relative to the current time. This enables users to visualize recent fire progression and currently active fire fronts for wildland fires. The temporal classification displays active fire detections occurring in the past 0 to 6 hours (deep red), detections occurring 6 to 12 hours earlier (red) and 12 to 24 hours earlier (orange), and detections occurring previous to the last 24 hour period (yellow).
Setting the Time Since Detection Classification in FIRMS
- Open the fire map viewer for FIRMS Global or FIRMS US/Canada
- Select the Time Since Detection choice from the pick list associated for a particular satellite/sensor source in the FIRMS display control window to apply this classification to the active fire detection data for that source layer
- To apply it for all the MODIS and VIIRS active fire detection layers, click the Time Based button at the top of in the FIRMS display control window
Examples of active fire data displayed with the time since detection classification:
Examples for setting the time since detection classification in FIRMS
SNPP and NOAA-20 VIIRS active fire detection locations in Northern California symbolized by their time since detection at ~17:00 PDT June 30, 2021
SNPP and NOAA-20 VIIRS active fire detection locations in Western Ontario symbolized by their time since detection at ~19:00 CDT June 30, 2021
FIRMS has added additional capability to integrate satellite active fire detection data as streaming web services. Several new geospatial web services are now available to meet the needs of end users in visualizing and analyzing these data in the context of geospatial information in desktop or web mapping applications.
New Web Map Services
In addition to legacy FIRMS Web Map Services (WMS) that provide MODIS and VIIRS active fire detection data for the past 24, 48, 72 hours or the past 7 days, new services are provided that display these data relative to their time since detection. New WMS options enable visualization of cumulative MODIS and VIIRS active fire data for the current calendar year in two temporal classifications that depict the data in its relative time since detection. Please see the WMS information page for FIRMS US/Canada and FIRMS Global for service connection information and tutorials on how to access the services.
Temporal classifications for the new MODIS and VIIRS active fire detection web map services available in FIRMS.
New Web Feature Services
FIRMS has also introduced new regional Web Feature Services (WFS) that stream the centroids of active fire detection pixels for MODIS and VIIRS as geographic point features. The services allow end users to manipulate and analyze features in the services using a geospatial client. These services are configured to enable access to MODIS or VIIRS active fire data for the past 24 hours or the past 7 days. Please see the WFS information page for FIRMS US/Canada and FIRMS Global for service connection information and tutorials on how to access the services.