themis/gbo engineering peer review 1 ucb, oct. 17, 2003 ground magnetometer gbo design
TRANSCRIPT
THEMIS/GBO Engineering Peer Review 2 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Sub-System Features
GPS Receiver Antenna and Electronics Integrated into one package
May be located >30M from host (RS232 signals)
NTP compatible (<1msec time accuracy)
Flxugate Magnetometer ±72KnT dynamic range @ 0.03nT Resolution (~22 bits)
Offset DAC system for 72 4KnT ranges per axis
2 Vectors per second data rate
Low Power < 2W
Small Size 22cm x 13cm x 5cm
Ruggedized All Weather Sensor Design
USB interface for data retrieval and firmware upload
THEMIS/GBO Engineering Peer Review 3 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
GPS Receiver Block Diagram
GBO Magnetometer To Fluxgate Sensor
Antenna Heater
To Power SupplyPower ControlRS232 bidirectional
Survival Heater and Thermistor
GPS Power
RS232 bidirectional
USB InterfaceGBO Data System
GPS Receiver
Up to 30M cable length
Up to 50M cable length
12VDC
THEMIS/GBO Engineering Peer Review 4 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
FEEDBACKFEEDBACK
FEEDBACKFEEDBACK
FEEDBACKFEEDBACK
UCLA Sigma-Delta
Fluxgate Magnetometer
MAGCLOCKS
MAGCLOCKS
SHIFT & INTERNALLOGIC CLOCKS
SHIFT & INTERNALLOGIC CLOCKS
FEEDBACKLATCH
FEEDBACKLATCH
DATA FORMATING& OUTPUT
REGISTERS
DATA FORMATING& OUTPUT
REGISTERS
DIGITALNOISE SHAPING
FILTER
DIGITALNOISE SHAPING
FILTER
XILINX XC2S50
DRIVECIRCUIT
DRIVECIRCUIT
SYNC.Demodulator
SYNC.Demodulator
3 AXIS SENSORASSEMBLY
3 AXIS SENSORASSEMBLY
INTEGRATORINTEGRATOR
INTEGRATORINTEGRATOR
SYNC.Demodulator
SYNC.DemodulatorINTEGRATOR
INTEGRATORINTEGRATOR
INTEGRATOR
SYNC.Demodulator
SYNC.DemodulatorINTEGRATOR
INTEGRATORINTEGRATOR
INTEGRATOR
SYSTEM CLOCKSYSTEM CLOCK
OffsetDAC
OffsetDAC
OffsetDAC
OffsetDAC
OffsetDAC
OffsetDAC
OFFSETDAC
OUTPUTREGISTERS
OFFSETDAC
OUTPUTREGISTERS
SensorHeater
SensorHeater
ElectronicsHeater
ElectronicsHeater
THEMIS/GBO Engineering Peer Review 5 UCB, Oct. 17, 2003
xdt
Integrator 1
Comparator
1-bit
DAC
xdt
Integrator 2
FPGA
Digital
Decimation
Filter
21-bits
x(n)
x(t)
y(t)- -Fs:fs
32:1
Fs y(n)
Fluxgate
Sensor
AC
Coupling
Input
Amplifier
Synch
demodulator
xdt
IntegratorBand-Pass
Filter
Feedback
Resistor
Analog-to-Digital
Converter
ADC16-24 bits
Second Order Sigma-Delta Modulator
Ground Magnetometer – GBO Design
THEMIS/GBO Engineering Peer Review 6 UCB, Oct. 17, 2003
Fluxgate
Sensor
AC
Coupling
Input
Amplifier
Synch
demodulator
xdt
Integrator 1
xdt
Integrator 1 Comparator
1-bit
DAC
Feedback
Resistor
FPGA
2FO
DQ
FO/2
1
1
-
Comb Filter
Decimate 32IIR FilterIIR Filter Decimate 75
18-bits2Hz Data
2nd Order Fluxgate Magnetometer
-
2nd Order Fluxgate Magnetometer
Ground Magnetometer – GBO Design
THEMIS/GBO Engineering Peer Review 7 UCB, Oct. 17, 2003
UCLA GBO MAGNETOMETER SYSTEM OVERVIEW
Ground Magnetometer – GBO Design
PIC18F452
Micro-Controller
GPS Serial Interface
DB
15FU
SB
COM PORT
USB Interface
USB Interface
DB
9F
PPS Timing Interface
PPS Timing Interface
GPS Heater & Power Interface
GPS Heater & Power Interface
TCXOTCXO
XC2S50
FPGA
FPGA FLASH
FPGA FLASH
Power Regulation
+/-15V +5V
Power Regulation
+/-15V +5V
DIN
-5F
Axis 1Axis 1
Axis 2Axis 2
Axis 3Axis 3
DB
25F
DriveDrive
Sensor Heater
Sensor Heater
THEMIS/GBO Engineering Peer Review 8 UCB, Oct. 17, 2003
UCLA GBO Magnetometer Chassis - Mechanical
Ground Magnetometer – GBO Design
DB15F – GPS Receiver
DB9F – GBO Data System
USB Type B – GBO Data System
21.6cm
DB25F – Fluxgate Sensor
DIN 5F – +12V Power Input
5.1cm
12.7cm
THEMIS/GBO Engineering Peer Review 9 UCB, Oct. 17, 2003
UCLA GBO Magnetometer Sensor - Mechanical
DB25M
~100cm
Ground Magnetometer – GBO Design
12.7cm
50Meters (Max)
THEMIS/GBO Engineering Peer Review 10 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Ground Magnetometer Fluxgate Sensor
~100cm
THEMIS/GBO Engineering Peer Review 11 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Ground Magnetometer Fluxgate SensorSub Components
THEMIS/GBO Engineering Peer Review 12 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Ground Magnetometer - Electrical
Input Voltage: (9 – 18)VDC
Input Current: GPS system 100ma.Magnetometer 150ma.Sensor Heater 600ma.Electronics Heater 100ma.
THEMIS/GBO Engineering Peer Review 13 UCB, Oct. 17, 2003
GBO Magnetometer Data Timing
Sampling determined by TCXO (<10ppm aging)
Time Tagging determined by GPS (<100μsec) GPS
GPS Time Quality Factor Logged
Time Recalculated Periodically Typ. Hourly
Re-Synchronization at Programmable Rate Optional
Ground Magnetometer – GBO Design
THEMIS/GBO Engineering Peer Review 14 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Sigma-Delta Fluxgate Magnetometer Test Data
THEMIS/GBO Engineering Peer Review 15 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Sigma-Delta Fluxgate Magnetometer Test Data
THEMIS/GBO Engineering Peer Review 16 UCB, Oct. 17, 2003
GBO Magnetometer Data Products
Data Inputs Include: Configuration File (UCLA_GBO_ssss_Vxx_xx.INI)
uP Firmware File (UCLA_GBO_ssss_Vxx_xx.UPF)
FPGA Firmware File (UCLA_GBO_ssss_Vxx_xx.GAF)
Data Outputs Include: Mag Vector Data (ssssdddddd_MAG_hh_cc.RMD)
Mag Housekeeping Data (ssssdddddd_MAG_hh_cc.HKD)
Magnetometer Log Data (ssssdddddd_MAG_hh_cc.LOD)
Mag Calibration Data (UCLA_GBO_ssss_Vxx_xx.CAL)
Ground Magnetometer – GBO Design
THEMIS/GBO Engineering Peer Review 17 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
GBO Magnetometer Vector Data File Format
[File Preamble(I32)] [File Name(string “ssssdddddd_MAG_hh_cc.RMD”)]
[Nominal Vector Interval in msec (I32)]
[Time of next data point(string “mmddyyyy-hh:mm:ss-mmm”)]
[Number of vectors to follow N (I32)] [Vector 1 (3xI32)] [Vector 2 (3xI32)] ……
….. [Vector N-1 (3xI32)] [Vector N (3xI32)]
[Time of next data point(string “mmddyyyy-hh:mm:ss-mmm”)]
[Number of vectors to follow N (I32)] [Vector 1 (3xI32)] [Vector 2 (3xI32)] ……
….. [Vector N-1 (3xI32)] [Vector N (3xI32)]
[File Postamble(I32) ]
THEMIS/GBO Engineering Peer Review 18 UCB, Oct. 17, 2003
GBO Data System Software Features
Magnetometer Setup using LabView Program Real time display of three axis time series data
Real time display of three axis Power Spectra
Operator control of Magnetometer settings including, Heaters, Offset DACs, and operating modes
Autonomous Operations using C++ Program Command Line execution
Initialization controlled via Configuration file
Ground Magnetometer – GBO Design
THEMIS/GBO Engineering Peer Review 19 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Ground Magnetometer GBO Schedule
THEMIS/GBO Engineering Peer Review 20 UCB, Oct. 17, 2003
Ground Magnetometer – GBO Design
Ground Magnetometer GBO Schedule