Lightning Data

The University at Albany, State University of New York, through a cooperative agreement with Vaisala, offers data from the National Lightning Detection Network (NLDN) to universities over the Internet. These data are available at no cost for education and research, under constraints established by Vaisala and SUNY-Albany and outlined below.

NLDN data emanates from UAlbany via the same LDM mechanisms employed for other types of information in our Internet Data Distribution (IDD) initiative.

Data delivery overview

UAlbany runs an LDM server that is the primary distribution point for NLDN data. Each individual flash detected by the NLDN is collected in a six-minute bin before being ingested into the SUNY-Albany LDM server. The data consists of a binary packet containing the following fields for each lightning flash:

     Field               Example
     -------------------+---------------------
     date/time (msec)    09/22/93 10:22:33.334
     latitude                            47.33
     longitude                         -87.116
     polarity/signal strength           -188.7
     multiplicity                            6
     ellipse angle                         174
     semi-major axis                       6.0
     eccentricity                          2.0
     chi-square                            1.0

The specifics for the binary NLDN data record contained in the IDD is:

     Size     Name      Description
     --------+---------+----------------------------------------------------
     char[4]  NLDN      'NLDN' marks the start of record
     int[4]   tsec      time in seconds since 1970
     int[4]   nsec      nanoseconds since tsec (seems to be thousandths)
     int[4]   lat       latitude [deg] * 1000
     int[4]   lon       longitude [deg] * 1000
     short[2] fill      padding
     short[2] sgnl      signal strength * 10 [150 NLDN measures ~= 30 kAmps]
     short[2] fill      padding
     short[2] mult      multiplicity [#strokes per flash]
     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, for example, a decoder may be automatically invoked to convert the NLDN-native format to, for example, a Unidata netCDF file. Unidata and SUNY have established an IDD feedtype, NLDN FT 14, for this data stream.

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 lightning data.

How to access NLDN data

UAlbany controls LDM access to the NLDN data; universities interested in receiving the NLDN data should contact David Knight. These universities will be able to use the data for one month to determine the scope and usability of the data. After that time, a brief, one-page document (synopsis) of the planned use/publication must be submitted for Vaisala's approval. Submissions should be made to Dr. David Knight as above. Vaisala's policy prohibits redistribution of or financial gain from these data.

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