National Lightning Detection Network (NLDN)
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The University at Albany, State University of New York, through a cooperative agreement with Vaisala, offers a real-time LDM data feed from the National Lightning Detection Network (NLDN) to United States-based colleges and universities. This feed is available at no cost for education and research, under constraints established by Vaisala and the University at Albany, SUNY. Please note that UAlbany is only able to provide real-time NLDN data. Please contact Vaisala for information regarding requests for archived data.
he University at Albany controls LDM access to the NLDN data. Vaisala's policy prohibits redistribution-of or financial gain-from the NLDN data.
Universities interested in receiving the NLDN data should contact:
UAlbany Department of Atmospheric and Environmental Sciences Support
support@atmos.albany.edu
Kevin Tyle
Department of Atmospheric and Environmental Sciences
University at Albany
State University of New York
ktyle@albany.edu
NLDN data emanates from UAlbany via the Unidata LDM mechanism.
UAlbany runs the LDM server that is the primary distributor for NLDN data. A description of the data records for flash events is contained in the following tables:
| Field | Example |
|---|---|
| date [CCYYMMDD] | 19930922 |
| time [HH:MM:SS.msec] | 10:22:33.334 |
| latitude | 47.33 |
| longitude | -87.116 (west negative convention) |
| polarity/signal strength | -188.7 |
| multiplicity | 0 |
| ellipse angle | 174 |
| semi-major axis | 6.0 |
| eccentricity | 2.0 |
| chi-square | 1.0 |
| Size | Name | Description |
|---|---|---|
| char[4] | NLDN | 'NLDN' marks the start of record |
| int[4] | nhead | number of 28 byte header record blocks (includes 'NLDN' and nhead) |
| char[] | (nhead*28 - 8) remaining header bytes (can be ignored) | |
| int[4] | tsec | seconds since 1970 |
| int[4] | nsec | nanoseconds since tsec (NB: this appears be milliseconds, not nanoseconds) |
| int[4] | lat | latitude [deg] * 1000 |
| int[4] | lon | longitude [deg] * 1000 |
| short[2] | fill | padding |
| short[2] | sgnl | signal strength * 10 (NB: 150 NLDN measures ~= 30 kAmps) |
| short[2] | fill | padding |
| char[1] | mult | multiplicity (#strokes per flash; zero for IDD-delivered records after 2015) |
| char[1] | fill | padding |
| char[1] | semimaj | semi-major axis |
| char[1] | eccent | eccentricity |
| char[1] | angle | ellipse angle |
| char[1] | chisqr | chi-square |
When a lightning data packet is received by an LDM server, a decoder may be automatically invoked to convert the NLDN-native format to, for example, a Unidata netCDF file, a GEMPAK point file, or a McIDAS MD file. The IDD feedtype, for this datastream is named LIGHTNING (FT14).
Software that allows McIDAS, GEMPAK, and the IDV to use NLDN data is available from Unidata. Contact support@unidata.ucar.edu for further information on how Unidata software may be used to analyze and display NLDN lightning data.
Vaisala's National Lightning Detection Network (NLDN) Lightning Explorer displays recent lightning activity across the entire continental United States.