Airborne GLM SimulatorFly’s Eye GLM Simulator

Mason G. Quick, Richard Blakeslee, Hugh Christian, Mike Stewart, Scott Podgorny, David Corredor

NASA Postdoctoral FellowZP-11 MSFC

Airborne GLM SimulatorObjectives

• Determine GLM Detection Efficiency• Validate the GLM events while observing the

same storms– location accuracy in space and time

• Provide calibration of the Optical Energy that is observed by the GLM– Background radiance (day/night)– Signal radiance

Fly’s Eye GLM Simulator• 5 x 5 array of radiometers

– OI: 777 nm• 5 extra spectral channels

– UV: 337 nm– UV: 400 nm– NI: 500 nm– Hα: 660 nm– N2: 675 nm– WideBand: 400-1000 nm

• Wide Angle Camera, normal frame rate• Electric Field Change Meter

FEGSTelescope Array

FEGSMission Requirements

• 1/3” CMOS sensor• 1080p HD resolution• 60 fps• Progressive Scan

• 1.4 mm fisheye lens• ~ 95° x 125° FOV

• HD-SDI video signal• GPS text overlay• Waypoint trigger tagging• Record to USB flash drive (or SD card)• 60GB/8HR flight

FEGSIntegrated Camera and DVR

FEGS

10 km

10 km

FEGS Footprint

FEGSData System Enclosure

FEGS Hardware

FEGSData System Enclosure

ER2 Rack

FEGS Enclosure

Data System

PreAmp ADCPhotoDiode

FPGA + Buffer

Solid State Drive

Micro Processor

Trigger

GPS

30 Optical Channels

USB 2.0

FEGS Optical Board Data Channels

FEGS Optical Board Block Diagram

2.5VREF

LVDS Receivers

+2.5VREF

SCLK (15Mhz)

-2.5VA -2.5VREG

--1.0V REG

-15VA

5.0V REG

+15VA

-15V

+15V

+3.3VD

+5.0VA

-1.0VA

ADC5LTC2376-18 ADC

CNV

SDO1 (Serial output to FPGA board)

LVDS DISTRIBUTIONDRIVERS

PD5 PD4 PD3 PD2 PD1

Bank 1 of 6

Notes:1. Analog front end AC coupled for XXXXXXX2. DC coupled for all others3. FPGA controlled digital triggering off AC coupled channels4. Temp Sensor ADC TBD

Banks 2 to 6

SDO2

SDO3

SDO4

SDO5

SDO6

ADC4 ADC3 ADC2 ADC1

From FPGA board

+5.0VA

5.0VREF

+5.0VREF +15.0VA

REV - 3/23/2015

ADC Front End

ADC Front End

ADC Front End

ADC Front End

ADC Front End

+3.3V

FEGS FPGA Board Block Diagram

LVDS DriversA3P600-PQ208I

+1.5v Reg

+1.5VDFPGA core

Osc

FPGA Clock

+3.3VD

CY7C1061DV33-10ZSXI

SRAM

SRAMLVDS Receivers

ADC Signalsto ADC BOARD

DS1830AS+

Reset

USB Module + 60Mhz CLK

Copernicus IIGPS

Antenna

TO MICRO

JTAGLVTTL TestHeader

Circular BufferControl

GPS Decoder & UART

SubsecondGenerator

Watchdog

USBFIFO

ADCControl

USBControl

+3.3V

REV - 3/23/2015

Notes:

Camera GPS

RS232Driver

ADC Signalsfrom ADC BOARD

ExternalTrigger in

Camera Trigger(LVTTL)

+12V

Data Rates

• 30 Optical Channels– 6 MB/s (22 GB/HR)

• Camera – 2 MB/s (7 GB/HR)

• E-Field– 22MB/s (80 GB/HR)

FEGS Calibration

• Spectral Response• Angular FOV• Sensitivity• Temporal Response• Linearity

• Real Observations?

Previous Measurements

- Amplitude- Integrated Energy- Rise Time- FWHM (duration)- Number of pulses- Inter-Pulse Interval- Complexity- Background Level

D.M. Mach, R.J. Blakeslee, J.C. Bailey, W.M. Farrell, R.A. Goldberg, M.D. Desch, J.G. Houser, Lightning optical pulse statistics from storm overflights during the Altus Cumulus Electrification Study, Atmospheric Research, Volume 76, 2005, Pages 386-401, doi:10.1016/j.atmosres.2004.11.039

Additional FEGS Applications

• Optimize LCFA– Spatial or temporal clustering– Accuracy of scientific results– Completeness of performance metrics

• Instrument Health/Degradation

Other Science Questions

• % radiation at 777.4 nm• Typical optical depths in cloud• TGFs• Dim events from ALTUS Cumulus

Electrification Study (ACES)?

Thank You

Total Lightning Optical Observations from Space

• Early indication, tracking, monitoring of storm intensification

• More timely and accurate forecasts and warnings

• In-cloud lightning dominates severe storms• Lightning “jump” identification• Lightning climatology

• Designed for 10 yrs of operation• Instrument Suite– Earth Viewing: ABI and GLM– Solar Viewing: SUVI and EXIS– SEISS and Magnetometer (in-situ space

environment)• Geostationary Orbit

GOES-R

Geostationary Lightning Mapper

GOES-R Expected GLM Area Coverage

Steven J. Goodman, Richard J. Blakeslee, William J. Koshak, Douglas Mach, Jeffrey Bailey, Dennis Buechler, Larry Carey, Chris Schultz, Monte Bateman, Eugene McCaul Jr., Geoffrey Stano, The GOES-R Geostationary Lightning Mapper (GLM), Atmospheric Research, Volumes 125–126, May 2013, Pages 34-49, ISSN 0169-8095, http://dx.doi.org/10.1016/j.atmosres.2013.01.006.

GLM• 1372 x 1300 pixel CCD FPA• Variable pitch CCD FPA• 8-14 km resolution• 2 ms integration• Radiance at 777.4 nm, 1 nm passband• Background Radiance• 7.7 mbps telemetric downlink• Expected DE of 90%• 20 second latency

GLM

Lightning Cluster

Filter Algorithm

Steven J. Goodman, Richard J. Blakeslee, William J. Koshak, Douglas Mach, Jeffrey Bailey, Dennis Buechler, Larry Carey, Chris Schultz, Monte Bateman, Eugene McCaul Jr., Geoffrey Stano, The GOES-R Geostationary Lightning Mapper (GLM), Atmospheric Research, Volumes 125–126, May 2013, Pages 34-49, ISSN 0169-8095, http://dx.doi.org/10.1016/j.atmosres.2013.01.006.