MARSIS Instrument Overview Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza” Mars Express Data Workshop Mars Express Data Workshop ESAC, Villafranca del Castillo ESAC, Villafranca del Castillo Madrid (Spain) Madrid (Spain) MARSIS Instrument & Operation Concepts MARSIS Instrument & Operation Concepts 9 -11 June 2008 9 -11 June 2008 Andrea Cicchetti Andrea Cicchetti Raffaella Noschese, Marco Cartacci, Stefano Giuppi Raffaella Noschese, Marco Cartacci, Stefano Giuppi
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MARSIS Instrument Overview Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza” Mars Express Data Workshop ESAC, Villafranca del Castillo.
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MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
Mars Express Data WorkshopMars Express Data Workshop
ESAC, Villafranca del CastilloESAC, Villafranca del CastilloMadrid (Spain)Madrid (Spain)
9 -11 June 20089 -11 June 2008Andrea CicchettiAndrea Cicchetti
Raffaella Noschese, Marco Cartacci, Stefano GiuppiRaffaella Noschese, Marco Cartacci, Stefano Giuppi
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
Table Of ContentsTable Of Contents
1. MEX Orbital Configuration.2. MARSIS Working Range.3. Night Time Environment.4. Day Side Environment.5. Example of MARSIS Timeline.6. Main Instrument Parameters.7. MARSIS Block Diagrams .8. Tracking and Acquisition Concepts.9. Doppler Processing.10.Raw Data Collection (Flash Memory Utility)11.Global Coverage per Band achieved until
29/Feb/0812.Phobos Observation Criteria and latest Results.13.Overview of the Support Tools
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
1 MEX Orbital Configuration1 MEX Orbital Configuration
Mars Express was Mars Express was successfully launched on successfully launched on 2 June 2003 from 2 June 2003 from Baikonur, Kazakhstan, by Baikonur, Kazakhstan, by a Russian Soyuz rocket.a Russian Soyuz rocket.
Following a cruise of Following a cruise of almost 7 months, the SC almost 7 months, the SC was captured into orbit was captured into orbit on 25 December 2003 on 25 December 2003 and soon established a and soon established a highly elliptical polar highly elliptical polar orbit with a closest orbit with a closest approach to the surface approach to the surface of about 300 Km and a of about 300 Km and a period of about 6.65 hperiod of about 6.65 h
Periapsis ~ 300Km
Apoapsis~ 10.000Km
N
w
ORBIT 5851
Event UTC PERI2008 JUL 23 03:37:24
MEX Orbital Plane
Mars
MARSIS MARSIS Working Slot Working Slot
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
2 MARSIS Working Range2 MARSIS Working Range
~ 300Km
SC Altitude
Mars
~ 1200Km
~ 900Km
AIS AIS
5 min 5 min
Sub Surface Sounding Modes or AIS
30 min
MARS Pericenter
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
3. Night time Environment3. Night time Environment
H2O Deposit
~ 5 Km
MARS Surface
MARS Sub Surface
~130 Km
Soft Ionosphere Layer
1.8 MHz3.0 MHz
Good Penetration Capabilities
Dipole antenna
Monopole antenna
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
4. Day time Environment4. Day time Environment
H2O Deposit
~ 1-2 Km
MARS Surface
MARS Sub Surface
4.0 MHz5.0 MHz
Dipole antenna
Monopole antenna
80 ~130 Km
Strong Ionosphere Layer
Acceptable Penetration Capabilities
The lowest Bands (1.8 and 3.0 MHz)Will be completely reflected by the Ionosphere layer
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
In the deep day side it is not possible to use the lowest radar bandsdue to the upper ionosphere layer that will completely reflects the MARSIS Signals.
Mars Surface
Orbit 4628 (11/Aug/07)
295.7 Km
Upper Ionosphere Layer in the day side
150 Km
145.7 Km
4.1 Ionosphere Reflection proprieties in the day side
Band 1 (1.8 MHz)
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
5 Example of MARSIS Timeline5 Example of MARSIS Timeline
SC [SEA]/Altitude
AIS
Time Off Peri [min]
-15°
SS3B1/B2
SS3B2/B3
SS3B3/B4
AISAIS
0°
35°
-20.0 -15.0 0.0 15.0 20.0
~1200 Km ~1200 Km
~ 900 Km ~900 Km
~ 300 Km
Day Side
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
6 Main instrument Parameters6 Main instrument Parameters
Sub Surface Sounding ParametersSub Surface Sounding Parameters
Centre Frequencies:Centre Frequencies:Band 1 Band 1 1.8 MHz 1.8 MHzBand 2 Band 2 3.0 MHz 3.0 MHzBand 3 Band 3 4.0 MHz 4.0 MHzBand 4 Band 4 5.0 MHz 5.0 MHz
Bandwidth = 1.0 MHz Bandwidth = 1.0 MHz δδ= 150m (free space depth resolution) = 150m (free space depth resolution) Transmit pulse Length = 250 usTransmit pulse Length = 250 usPRF = 127.267 Hz (Pulse Repetition Frequency)PRF = 127.267 Hz (Pulse Repetition Frequency)Receive Window Size = 350us Receive Window Size = 350us Sounder Dynamic Range = 40 to 50 dBSounder Dynamic Range = 40 to 50 dB
Surface Sounding Altitude Range = 250 to 900 KmSurface Sounding Altitude Range = 250 to 900 Km
Ionospheric Sounding ParametersIonospheric Sounding Parameters Maximum Altitude = 1200 KmMaximum Altitude = 1200 Km
Frequency Range = 0.1 to 5.5 MHzFrequency Range = 0.1 to 5.5 MHz
Minimum Frequency Step = 10.937 HzMinimum Frequency Step = 10.937 Hz
Repetition Period = 7.38sRepetition Period = 7.38s
Dipole Antenna element length = 20 mDipole Antenna element length = 20 mMonopole Antenna length = 7 mMonopole Antenna length = 7 m
Total Mass = 20 KgTotal Mass = 20 KgDC Operation Power = 60 WDC Operation Power = 60 W
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
7 MARSIS Block Diagram7 MARSIS Block Diagram
MARSIS Consist ofMARSIS Consist of : :
1.1. A sounder channel containing a programmable signal generatorA sounder channel containing a programmable signal generator2.2. a surface cancellation channela surface cancellation channel3.3. a dual channel data processora dual channel data processor4.4. a power and control subsystem which controls all the sounder functionsa power and control subsystem which controls all the sounder functions
A/D Converters A/D Converters Operate at a Sampling frequency of 2.8 MHz (8 bit) Operate at a Sampling frequency of 2.8 MHz (8 bit)
PowerPowerAndAnd
ControlControl
ProcessorProcessor
S/CS/C
TransmitterTransmitter
ReceiverReceiver
SignalSignalGeneratorGenerator
Analog toAnalog toDigitalDigital
ConverterConverter
11
ReceiverReceiverAnalog toAnalog to
DigitalDigitalConverterConverter
22
33
44
MonopoleMonopole
DipoleDipole I/QI/QSynthesisSynthesis
I/QI/QSynthesisSynthesis
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
Two frequencies operation: Two frequencies operation:
four echoes are received, two from Dipole four echoes are received, two from Dipole channel and two from Monopole channel. channel and two from Monopole channel.
Echoes are processed to synthesize a Echoes are processed to synthesize a single Doppler filter. single Doppler filter.
Complex data for each of the four Complex data for each of the four synthesized Doppler filters, before range synthesized Doppler filters, before range compression, are transferred in the compression, are transferred in the science source packet data format.science source packet data format.
This mode allows coherent clutter This mode allows coherent clutter cancellation on two frequency bands by cancellation on two frequency bands by means of dual antenna clutter cancellation means of dual antenna clutter cancellation ground processing.ground processing.
Rx Monopole Ch
RX1
RX2
450 us
t [us]
Trigger
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
Two frequencies operation: Two frequencies operation:
two echoes are received, two from Dipole two echoes are received, two from Dipole channel. channel.
Echoes from the Monopole channel are not Echoes from the Monopole channel are not processed, while echoes from the Dipole processed, while echoes from the Dipole channel are processed to provide a channel are processed to provide a Multilooked information for a single Doppler Multilooked information for a single Doppler filter using parallel synthesis of five Doppler filter using parallel synthesis of five Doppler filters on board. filters on board.
The power detected samples for each of the The power detected samples for each of the two multilooked Doppler filters synthesized two multilooked Doppler filters synthesized are transferred in the science source packet are transferred in the science source packet data format.data format.
Rx Monopole Ch
t [us]
No signals processed from MonopoleChannel
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
7.4 Subsurface Sounding Mode SS3
Rx Dipole Ch
RX1
RX2
450 us
t [us]
Trigger
Tx Phase
TX1
TX2
250 us 250 us
450 us
t [us]
Two frequencies operation: Two frequencies operation:
This mode allows downlink, for each frame, This mode allows downlink, for each frame, of the I and Q data of three Doppler filters of the I and Q data of three Doppler filters collected on the dipole antenna channel at collected on the dipole antenna channel at two frequencies. two frequencies.
Range processing is performed on the Range processing is performed on the ground.ground.
Rx Monopole Ch
t [us]
No signals processed from MonopoleChannel
99.99 % Of the data have been 99.99 % Of the data have been collected with this modalitycollected with this modality
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”
7.5 Subsurface Sounding Mode SS5
Single frequency operation: Single frequency operation:
two echoes are received, one from the two echoes are received, one from the Dipole and one from the Monopole. Dipole and one from the Monopole.
Echoes are actually pre-summed over Echoes are actually pre-summed over groups of four to increase the Signal to groups of four to increase the Signal to Noise Ratio. Noise Ratio.
Pre-summed Echoes are processed to Pre-summed Echoes are processed to synthesize three central Doppler filters for synthesize three central Doppler filters for each channel. each channel.
Complex data of the six synthesized Complex data of the six synthesized Doppler filters before range compression, Doppler filters before range compression, are transferred in the science source packet are transferred in the science source packet data format.data format.
This mode uses a short pulse waveform to reduce This mode uses a short pulse waveform to reduce the impact of uncontrolled sidelobes on deep the impact of uncontrolled sidelobes on deep subsurface reflectionssubsurface reflections
Tx Phase
TX1
30 us
t [us]
TX2
TX3
TX4
Rx Dipole Ch
t [us]
TriggerTX1
TX2
TX3
TX4
Rx Monopole Ch
t [us]
TriggerTX1
TX2
TX3
TX4
MARSIS Instrument Overview
Andrea Cicchetti - Infocom Department - University of Rome “La Sapienza”