GLM is coming: The origin of the GLM

The Geostationary Lightning Mapper (GLM) successfully launched aboard GOES-R (now GOES-16) on November 19, 2016.  Now we are a week away from the initial preliminary, beta data observations being made available.  This is an exciting time, especially with some of the early public release imager from the GLM available on the GOES-R multimedia page (  In advance of next week’s milestone here is some of the history that has led to the development of the GLM.

One of the earliest satellite-based instruments specifically designed for lightning observations was the Optical Transient Detector (OTD).  Figure 1 (below) shows the annual flash frequency for 1995 to 2000. This was developed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.  Amazingly, the OTD was built in nine months.  Launched on April 3, 1995 the OTD was placed in a near polar orbit allowing it to monitor lightning over much of the Earth during both the day and night.  However, the OTD only provides a few minutes a day for any given location.  This prevented the OTD from studying local weather activities, but allowed the OTD to study global lightning patterns and their evolution.  The OTD also launched at a time when the awareness of the important role lightning played in the Earth’s atmosphere was becoming better understood and that lightning was likely an indicator of the strength of convective storms.  OTD efforts would contribute to the discovery of lightning as an indicator of potential severe weather, what we now call lightning jumps.  Additionally, OTD discovered that the global flash rate is approximately 40 flashes per second.  Ultimately, the OTD’s contributions reinforced the need for lightning observations from geosynchronous orbit, which would ultimately lead to the development and launch of the GLM.


Figure 1:  Annual flash frequency from 1995 to 2000 from Christian et al. (2003).

Given its short production time, the OTD served as a production prototype for a more robust, low-Earth orbiting lightning sensor.  This new instrument was the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measuring Mission (TRMM).  The LIS was designed by scientists at the University of Alabama in Huntsville as well as NASA’s Marshall Space Flight Center.  Launched in 1997, LIS, and the TRMM satellite as a whole, far exceeded their projected service life and provided 17 years of continuous observations.  Unlike the OTD, the LIS was on an orbit that focused on the tropical regions of Earth.  However, LIS had superior detection abilities for both day and night.  Figure 2 (below) shows the lightning activity in the LIS field of view for 2012.  Once operational, the LIS has provided significant contributions to investigating convective and precipitation processes.  The long operational life of LIS has also helped identify most lightning active regions on Earth, such as Lake Maracaibo, Venezuela with 232 flashes per square kilometer per year!  Like the OTD, LIS reinforced the importance of a geostationary platform where storm morphology can be monitored continuously.  Many concepts in the design of the LIS have been used in the GLM instrument.


Figure 2:  Lightning Imaging Sensor observations of lightning across the instrument’s field of view for 2012.  Image courtesy of NASA’s Marshall Space Flight Center.

Stay tuned for the next “GLM is coming” blog post that will focus on the efforts to prepare for the Geostationary Lightning Mapper.

GOES-16 Advanced Baseline Imager Data Observes Severe Weather Event on Day 1!

Today marks the first day that the beta-mode Advanced Baseline Imager (ABI) data have been made available from GOES-16.  NASA SPoRT is obtaining the ABI data via the GOES Rebroadcast (GRB) data transmission system receiver located at the NASA Marshall Space Flight Center in Huntsville, Alabama.

Mother Nature provided some active weather through the Tennessee River Valley today as SPoRT team members worked to produce imagery from the receiver.  Below is a one hour animation of ABI data from 1817 to 1917 UTC updating every 5 minutes.  This shows Band 2 visible 0.64 µm imagery at a resolution of 0.5 km.  The imagery shows the line of storms as it entered northern Alabama.


GOES-16 ABI 0.64 um visible imagery from 1817 to 1917 UTC on 1 March 2017.  These data come from the GOES Rebroadcast (GRB) data transmission system receiver located at the NASA Marshall Space Flight Center in Huntsville, Alabama. (Full resolution)

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

For comparison, the following figure below shows the same ABI 0.64 µm imagery at 2006 UTC (0.5 km) side-by-side with the existing GOES-13 visible data at 2007 UTC (1 km).  Notice the impressive detail observed with the higher resolution GOES-16 imagery!


Comparison of GOES-16 ABI 0.64 um (left, 2006 UTC – 0.5 km) and the GOES-13 Imager (right, 2007 UTC – 1 km) on 1 March 2017.  The yellow circle highlights an overshooting top in Jackson County, Alabama.  These data come from the GOES Rebroadcast (GRB) data transmission system receiver and the GVAR receiver, both located at the NASA Marshall Space Flight Center in Huntsville, Alabama. (Full resolution)

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

NASA SPoRT Helps Prepare for GOES-R

November 19th has been eagerly anticipated by the meteorological community as it is the launch of the next-generation GOES-R satellite.  The satellite will carry a suite of space weather instruments as well as two Earth observing sensors.  The Advanced Baseline Imager (ABI) will provide three times more channels to view the Earth, four times greater spatial resolution, and 5 times faster coverage.  The ABI will provide new means to monitor atmospheric phenomena.  Additionally, GOES-R will carry the first ever lightning observation sensor on a geostationary platform; the Geostationary Lightning Mapper (GLM).  Numerous organizations, including NASA SPoRT, have been supporting the GOES-R Proving Ground for many years to aid the operational community in preparing for the new capabilities of GOES-R.

Specifically, NASA SPoRT has been formally involved with the Proving Ground since 2009, although much of our work prior to this point has provided relevant information with respect to GOES-R.  SPoRT has been primarily involved in two activities.  The first has been the assessment of and training for multi-spectral imagery, often called red-green-blue (RGB) composites.  The RGB composites are used to combine multiple single channels into a single image in order to help emphasize phenomena that forecasters wish to monitor.  This can range from air mass microphysics to atmospheric dust.  This work has leveraged work by Europe’s EUMETSAT organization who first developed several of these RGB composites for their Meteosat Second Generation satellite.  SPoRT has worked with NASA’s MODIS instruments from Aqua and Terra as well as the JPSS VIIRS instrument to create the respective RGBs from polar orbiting instruments.  These snapshot demonstrations provided forecasters local examples of RGB composites to allow them to investigate these products prior to GOES-R’s launch.  SPoRT has also coordinated with other product developers to help transition their early development work to National Weather Service forecasters.  This included the University of Alabama in Huntsville’s GOES-R convective initiation product and the NESDIS quantitative precipitation product.


MODIS Dust RGB demonstrating a future capability of the GOES-R ABI. Dust (magenta) can be seen approaching Las Vegas, Nevada.

In additional to the ABI work, SPoRT has been integral to supporting total lightning (intra-cloud and cloud-to-ground) observations in operational applications.  This dates back to 2003 with the first transition of experimental ground-based lightning mapping arrays that evolved into the pseudo-geostationary lightning mapper (PGLM) product in 2009 to provide operational training for the GLM.  Since then, SPoRT has developed the GLM plug-in for the National Weather Service’s AWIPS system, has personnel serving as the National Weather Service liaison for the GLM, and have developed foundational training that is being provided to every forecaster in the National Weather Service.


Sample of the pseudo-geostationary lightning mapper demonstration product in AWIPS being used for training on the Geostationary Lightning Mapper.

SPoRT will continue to be actively engaged in GOES-R applications post launch.  This will take the form of developing an applications library, or short 3-5 focused case examples, for both the ABI RGBs and the GLM.  SPoRT will also participate in the formal applications training for RGBs and GLM that will be released to the National Weather Service.  Lastly, SPoRT will be leading an operational assessment of the GLM with National Weather Service forecasters and associated emergency managers.


GOES-R launching on November 19, 2016!

QPE (NESDIS) product assessment in Alaska

As part of its GOES-R Proving Ground activities, SPoRT is partnering with Bob Kuligowski (NESDIS) and Alaska WFOs and RFC to assess the Quantitative Precipitation Estimate (QPE) product suite at high latitudes.  The intensive evaluation period will begin July 15 and go until September 15.  The QPE product has been developed in preparation for GOES-R. The QPE algorithm uses the current GOES longwave IR and water vapor channels and is calibrated in near-realtime using microwave sounding retrievals from a variety of satellites (TRMM, NOAA 18 & 19, METOP-A and B). In the GOES-R era, an additional 3 IR channels will be incorporated with the improved resolution to 2km. While the QPE product is better suited to convective type precipitation, this assessment with Alaska operational users is looking at the value of the product at high latitude and what adjustments might be made to improve its use in regimes with more stratiform, low-top precipitation.  Below is a comparison of the QPE to the AK RFC post analysis of the 24-hour precipitation ending on July 7 at 1200Z.  While fairly good agreement exists in some areas, the question is how well the QPE product can provide guidance in low density observation areas at high latitude.

To see a web display of product suite over several domains go to the SPoRT Real-Time Data page for QPE.


QPE 24-hour accumulation ending July 10, 2013 at 1200Z over Alaska domain. Product created by NOAA/NESDIS, transitioned via NASA/SPoRT for use in AWIPS by NWS users.


Web graphic of 24-hour precipitation estimate from the Alaska River Forecast Center ending July 10, 2013 at 1200Z.

A MODIS Hybrid

The SPoRT program is one of many organizations participating in the GOES-R Proving Ground to help prepare the meteorological community for the capabilities that will be available aboard GOES-R when it launches in 2015. Part of this work is to look for current observation capabilities that mirror what GOES-R will have. The MODIS instruments aboard the Aqua and Terra satellites have similar resolution and spectral channels to the planned ABI (Advanced Baseline Imager) instrument. Therefore, it is an excellent demonstration of future capabilities. However, the MODIS instruments are aboard polar orbiting satellites, meaning that unlike conventional geostationary GOES imagery swaths, data are available only when MODIS passes overhead. This creates poor temporal resolution that is unsuitable for many forecasters who prefer the ability to loop satellite data.

To address this issue in SPoRT’s Proving Ground activities, SPoRT personnel took existing GOES data, available at 30 minute intervals, and embedded the higher resolution MODIS swaths into the GOES data whenever MODIS was available. The result, shown in the figure below, creates a product available at a high enough temporal resolution to allow for animated loops and allows forecasters better access to MODIS data as it is no longer presented as an isolated snapshot. With the initial demonstration, SPoRT saw that this process could be applied to the current MODIS product suite now to enhance the utility of the MODIS data for all of our partners and not just with the Proving Ground activities. Efforts are now underway to provide this hybrid product in AWIPS to our National Weather Service partners as well as within SPoRT’s AWIPS II demonstration work.

This image, produced by Matt Smith and Kevin Fuell from 20 September, shows the 11 micron infrared hybrid product. The MODIS and GOES imagery are separated by the blue, dashed line. The bottom and right sides show the lower resolution (4 km) GOES IR image alongside the high resolution (1 km) MODIS IR data over the Four Corners region of the southwest United States.