The ZEUS+STARNET data set gathers the following information by columns
Updated October 2009
Carlos A. Morales

This dataset holds a collaboration between ZEUS and STARNET lightning
detection networks in an effort to produce the best available data
on sferics. The data still requires some quality control, but the users
can use some of the quality flags detailed in the text to check if the
position is reliable or not. In the following months, we should make
an analyses on the location accuracy and detection efficieny that will
be posted to everybody.

The data set is stored on the starnet webpage at the following link:
http://www.zeus.iag.usp.br/AMMA/ftp/tar/


any question, e-mail: morales@model.iag.usp.br

Column 1: year
Column 2: month
Column 3: day
Column 4: hour (GMT)
Column 5: minute
Column 6: second
Column 7: mili-second
Column 8: latitude
Column 9: longitude
Column 10: major ellipse error of the ATD solution (m)
Column 11: ATD error in micro-seconds
Column 12: Quality control (0,1,2)
Column 13: Polarity (0,1,2,3) (+-)
Column 14: Number of Rx employed in the Solution (4,5,6,7)
Column 15: Number of ATD pairs employed in the Solution (6-21)
Column 16: UK rx  
Column 17: Denmark rx  
Column 18: Romania rx  
Column 19: Cyprus rx  
Column 20: Athens rx  
Column 21: Portugal rx   
Column 22: Ethiopia rx 
Column 23: Tanzania rx 
Column 24: South Africa rx
Column 25: Nigeria Rx 
Column 26: Daka Rx (rx not available) 
Column 27: Guadeloupe (French Island-Caribean) Rx
Column 28: Fortaleza-Brazil Rx
Column 29: Sao Paulo-Brazil Rx

Major ellipse error: It represent the major axis of the ellipse error that 
		     circumscribes the ATDs. The lower the value, better the
		     solution. (This error is still under analyses, so don't
		     take too much in consideration, use the ATD error
		     instead).

ATD error: It represents the Residual Error of the ATD solution. The values
	   lower than 20 micro-seconds are considered acceptable, and it is
	   expected to have low location errors according to the theoretical
	   model.

Quality control: It a simplification of the ATD error/Major Axis that is 
	   used to diagnose the location accuracy: 0-Good; 1-Questionable;
	   2-Bad

Polariy: It is the retrieved ELF polarity (+ or -), where the values represent
           confidence level (1-low; 2-median; 3-high) and 0 no confidence
	   The values of -9 means that the polarity was not available in the reprocessing.

Number of Rx: It tells how many receivers were employed in the solution

Number of ATDs: It tell how many ATDs were used in the solution. If we had
	   4 rx, we have a maximum of 6 ATDs (combination of 4, 2 a 2); 5 rx
	   have 10 ATDs, 6 rx have 15 ATDs and 7 rx have 21 ATDs. The ATDs
	   employed in the solution passed a quality control, and if it does
	   not pass, it is not used.  So, you might have some solutions that
	   did not used the maximum number of ATDs according to the number of
	   rx available

The Columns (15-28) Indicate which receivers were available (1) or not (0).
	   In this data set we have only the African and American receivers
	   available, i.e., Ethiopia, Tanzania, South Africa, Nigeria, Guadeloupe
	   Fortaleza and Sao Paulo.
	   
	   
In the ZEUS data example (the first 3 below) we have the following information:

Sferics observed on October 12th 2008, at 23:00:02.649726 located at 
latitude=-4.37723 and lontitude=-72.91611, with an estimated major axis error=7.112 km
with an ATD error of 16.0 us, quality good, 4 rxs avaible and 6 ATDs were
employed. The Rx Sao Martinho, Campo Grande, Guadloupe and Sao Paulo were available.


2008  10 12 23  0  2 649726   -4.37723  -72.91611     7112  16.0  0 -3  4  6 0 0 0 0 0 0 0 0 0 1 1 1 0 1
2008  10 12 23  0  4  23439   -4.18725  -72.13458     3642  15.6  0  3  5 10 0 0 0 0 0 0 0 0 0 1 1 1 1 1
2008  10 12 23  0  5 782687   -7.55228  -75.02688     7289  16.4  0  0  4  6 0 0 0 0 0 0 0 0 0 1 1 1 0 1



The FORTRAN format to read the data is:

	n_receiver_ZEUS=14

	read(40,200)year,month,day,hour,minuto,second,milisecond,
     1           ,lat,lon,major_ellipse,
     1           userEr,qual,Pol,nRx,nPr,
     1           (id_rx(i),i=1,n_receiver_ZEUS)


200 format(I4,1x,5I3,1x,I6,2f11.5,I9,f6.1,4i3,14i2)



The rx locations in case someone is interest are the following:


-- UK --

# ID number
   1

# latitude
   51.14533

# longitude
   -1.43968

# -- Roskilde --

# ID number
   2

# latitude
   55.69392

# longitude
   12.09893

# -- Iasi --

# ID number
   3

# latitude
   47.17122

# longitude
   27.62769


-- Larnaca --

# ID number
   4

# latitude
   34.87351

# longitude
   33.61727

# -- Athenas --

# ID number
   5

# latitude
   38.04718

# longitude
   23.8651

# -- Lisboa --

# ID number
   6

# latitude
   38.76666

# longitude
   -9.13333

-- Addis Ababa --

# ID number
   7

# latitude
   8.98533

# longitude
   38.78622

# -- Dar es Salaam --

# ID number
   8

# latitude
   -6.87547

# longitude
   39.21081

# -- Hamilton --

# ID number
   9

# latitude
   -28.24964

# longitude
   28.33398

-- Nigeria --

# ID number
   10

# latitude
   7.76132

# longitude
   4.53535

# -- Dakar --

# ID number
   11

# latitude
   14.74724

# longitude
   -17.48833

# -- Guadalope

# ID number
   12

# latitude
   16.18177

# longitude
   -61.59016

# -- Fortaleza
-- Fortaleza

# ID number
   13

# latitude
   -3.79456

# longitude
   -38.55699

# gain adjustment
   0.0

# -- Sao Paulo

# ID number
   14

# latitude
   -22.68905

# longitude
   -45.00597