Description of the data columns included in the FEGS Pulse Data Version K2
2018/08/02
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List of Column Parameters

1. Pulse ID
2. Data Channel Number
3. GPS second for the start of the pulse
4. Subsecond for the start of the pulse
5. GPS second for the end of the pulse
6. Subsecond for the end of the pulse
7. Latitude
8. Longitude
9. Altitude
10. Roll Angle
11. Pulse Peak Radiance [W/m2 Sr]
12. Pulse Radiant Energy [J/m2 Sr]
13. Pulse 10-90 % Rise Time [ms]
14. Pulse 10-10 % Width [ms]
15. Pulse 50-50 % Width [ms]
16. Pulse Complexity
17. Signal-to-Noise Ratio
18. Mean Background Radiance [W/m2 Sr]
19. Maximum Pixel Number illuminated by the pulse
20. FOV Latitude 1
21. FOV Longitude 1
22. FOV Latitude 2
23. FOV Longitude 2
24. FOV Latitude 3
25. FOV Longitude 3
26. FOV Latitude 4
27. FOV Longitude 4

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Description

Summary:
FEGS Pulse Level Data provides timing, location, measured power, energy and temporal characteristics of the optical pulses identified in the FEGS data set.  To create this dataset the signal from all 25 radiometers in the main FEGS array are summed.  The background radiance was then estimated and subtracted from the optical time series and statistically large pulses were identified.

Column 1 lists the Pulse ID tag.  PulseID =1 is the first pulse detected during the flight.

Column 2 lists the Data Channel Number for the radiometer that detected the pulse.  For data version “K” the channel number is always 0 indicating the pulse was detected on the summed array waveform.

Columns 3-6 list the microsecond precision GPS-second and GPS-subsecond for the beginning and end of the pulse.

Column 7-10 list the 3D GPS location and Roll angle of the ER2 at the time of the pulse.  Roll angles greater than about 5 degrees indicate that the ER2 was in a turn, and the foot print of the FEGS FOV at cloud top will be highly skewed.  Pulses observed during a turn should be analyzed with caution.

Pulse Peak Radiance [W/m2 Sr] is the calibrated peak radiance measured for the detected pulse.  The radiance is assumed to be uniform over the 25 pixels in the main FEGS array.

Pulse Radiant Energy [J/m2 Sr] is the radiant energy measured by integrating the radiance over the duration of the pulse.  The radiance is assumed to be uniform of the 25 pixels in the main FEGS array.

10-90% Rise Time indicates the time period for the optical pulse to increase from 10% of the peak value to 90% of the peak value on the initial rise to peak.

10-10% Width indicates the duration of time the pulse radiance was larger than 10% of the peak value.

50-50% Width is the Full Width at Half Maximum of the pulse, and indicates the duration of time that the pulse radiance was larger than 50% of the peak value.

Pulse Complexity is a parameter included to quantify the number of radiance peaks superimposed upon one another during the identified pulse.  For low S/N ratios, this parameter greatly overestimates the actual number of peaks.  Currently this parameter is not trust worthy.

Signal-to-Noise Ratio is the ratio of the Pulse Peak Radiance to the Standard Deviation of the Background Radiance.

Mean Background Radiance is an estimate of the background radiance at the time of the identified pulse.

Columns 20-27 list GPS coordinates of a 4 point polygon that roughly outlines the FEGS FOV at the time of the pulse.  This spatial footprint assumes a cloud top height of 13 km which was typical for storms observed during the GOES-R Validation ER2 flight campaign.