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Mars Orbiter Mission
Presentation to MOM-AO TIS data analysis
By: JITENDRA KUMAR(SEDA)
on behalf of TIS team
Space Applications Centre, Ahmedabad
SAC - Bopal Campus,
28 February - 1 March, 2017
Thermal Infrared Imaging (MOM-TIS) Instrument
&Initial Results
Mars Orbiter Mission
TIS on Spacecraft and Configuration
Measures the thermal emission, in
TIR region, which can be map to get
surface composition and
mineralogy of Mars.
Science Objectives: Primary Objectives To map ground temperature of
Mars surface To map the mineralogy of Mars
surface
Mars Earth
Atmosphere CO2 (95%) N2 (78%)
Pressure 7.5 mbar 1013 mbar
Radius (Eq) 3397 km 6378 km
Distance from Sun 1.5 A.U. 1 A.U.
Gravity 0.38 that of Earth 2.7 that of Mars
Length of Day 24 hrs, 37 mins ~ 24 hours
Length of Year 687 Earth days 365 days
Surface Temp (Avg)
-63°C (133K to 290K)
14°C (248K to 323K)
Tilt of Axis 25° 23.5°
No. of satellites 2 (Phobos & Deimos)
1 (Moon)
Secondary Objectives To detect the hot spots, indicating
underground hydrothermal process To study the variability of
dust/atmospheric opacity of Martianatmosphere
TIS PayloadAbout Mars
Mars Orbiter Mission
Instrument Design & Development
General Configuration Payload Features Electro-Optical Subsystems : Optics / DHA / Electronics Payload Integration, Testing and Qualification Spectral calibration (Dispersion) In-Orbit (Earth) payload Performance
• Fore optics which focuses ray into a slit at its focal plane• A collimating optics which collimates radiation from the slit• A dispersing system which separates out different band• A focusing optical assembly which focuses different bands on to detectorMicrobolometer DHA with camera electronics converts the thermal signal into electrical signal (in terms of DN).
Instrument Design & Development: Configuration
Mars Orbiter Mission
Instrument Design & Development : Features
Parameter Value
Resolution258m @ Periareion (@372km)
55 km @ Apoareion (@80000km)
Foot print41km x 258 m @ Periareion
8800km x 55km @ Apoareion
Spectral region 7µm – 13µm, 12 bands
Spectral resolution ~500 nm (12 bands)
NEDT (Radiometric
performance)< 1K @300K
Data rate 6.5625 Mbps Size (mm) 413(L) x 339(W) x 123(H)
Mass (kg) 3.2
Power (W) 6
Mode Spectral Binning
Mode 3 (Nominal mode) 10 (12 bands)
Mars Orbiter Mission
Instrument Design & Development: EO Module Optics
Mars Orbiter Mission
7-13 µm, 120 spectral bands by dispersing gratings 120 bands binned electronically to generate 12 bands
Un-cooled Micro-bolometer
Fore Optics
Collimating Optics
Focusing Optics
Grating
Slit
Detector
Target signal is immersed in thermal background
Plane Reflection grating (dispersing element)
Window transmission > 70% in 7 to 13 µm
Readout modes
Self Scan, Differential, on chip filter enabled
CoolerIntegrated Thermo
Electric CoolerParameter ValueArray format 160 x 120 pixelsPixel size 50 µmPixel pitch 52 µmSpectral range 7 – 13 µm
Detector Bonded to Detector Mount
Instrument Design & Development: EO Module DHA
Mars Orbiter Mission
Instrument Design & Development: EO Module Camera Electronics
S/C InterfaceCamera Electronics
• Low noise Detector ProximityElectronics
• 16 bit digitization
• Detector temperature controlelectronics (Detector temperature iscontrolled within 10mK)
• Logic and control electronics withonboard data binning
• Low noise power supply electronics
• Power : 6W
• CE weight : 900g
TCEDPE PSELCE
Mars Orbiter Mission
TIS Payload under Vibration &Thermo-vacuum test
• FM payload has undergone environmental tests (Thermo-vacuum & vibration tests).
• Pre & post alignment and Spectral stability was maintained before and after the vibration as well as post thermo-vacuum cycling.
• Instrument successfully completed all the qualification tests.
TIS
Instrument Design & Development: Integration & Testing
Mars Orbiter Mission
TIS payload
TIS payload during thermo-vacuum test
Variable Temperature
Blackbody was operated between
200K to 320K
Blackbody Temperature Settings (deg K)
200 220 240 260 280 300 320
EOM Temperature (deg C)
10 15 20 25 30
Instrument Design & Development: Integration & TestingRadiometric calibration
300K280K260K
Mars Orbiter Mission
Instrument Design & Development: Integration & Testing Spectral Calibration
Spectral Dispersion(Calibration) Wavelength Vs. Row
Mea
n C
ou
nt
in S
pec
tral
Dir
ecti
on
Spectral Direction
Spec
tral
Dir
ecti
on
Spatial Direction
Wavelength = 8 µm Band = 20Wavelength = 10.3 µm Band = 67
Spectral range 7 – 13 µmBands 1-120
Mars Orbiter Mission
Launch: In –Orbit Performance
Launched on November 05, 2013 by rocket PSLV-XL
Mission Profile/TIS Operation Chronology
Geocentric Phase
In total there were about 6 Earth Bound Maneuvers carried out spread over 19 orbits. MOM spent about a month around earth. On 23rd November, 2013 TIS was switched on for the first time.
Geo-Centric Phase
Helio-Centric Phase(Cruise Phase)
Martian Phase
Heliocentric Phase
After inserting the MOM into the plane of mars, it enteredinto an elliptical heliocentric orbit (around sun). Duringthe cruise phase, Deep space imaging was carried out toverify the instrument’s overall performance.
Mars Orbiter Mission
Onboard Performance of Instrument
Geo Centric Phase-
TIS Switched ON In-orbit on 19th Nov. and 23rd Nov, 2013
Heliocentric Phase (Cruise) –
Instruments switched on periodically (5 times) for Health check and Dark performance
evaluation.
Mars Orbit Phase – MCC Acquired Images of Mars immediately after MOI on 24th Sep, 2014 TIS Imaging were conducted during Mars Orbiting Phase
(~150 times, from Sep 28, 2014 to Oct 22, 2015).
All Health Parameters Normal & Instruments Performance is consistent wrt to Lab data.
Mars Orbiter Mission
In –Orbit Performance:Preliminary Analysis
TIS Imaging were conducted during Earth bound phase (23 Nov.2013), Cruise Phase (5) and Mars Orbiting Phase (~150 from Sep28, 2014 to Oct 22, 2015).
TIS Imaging Around MarsThe MOM was in highly elliptical orbit around Mars, Considering the orbit and Mars-Sun alignment, Mars was imagedfrom Apoareion initially and gradually the imaging locations moved nearer to Mars.
Mars Orbiter Mission
Data Analysis & Results
Feature Variability Observed in TIS Data• Image Generation steps for a Bolometer based Sensor • Criticalities in Uncooled bolometer Data Analysis
Image Generation steps for a Bolometer based Sensor
Level-0 Data as Raw Image (function of seen Observed, Sensor Noise and Background) Offset Correction, based on Dark data Stripe/Non-uniformity Correction Correction, based on the Imaging location Calibration coefficient implementation
Mars Orbiter Mission
Real signal is immersed in very large thermal background. Large excursion in detector bias signal due to thermal background and detector
power dissipation.
Detector temperature is controlled within 10mK.
Background signal will be measured and subtracted frequently. Viewing of cold space @ 4K gives the
required reference.
Drift in Video counts due to thermal background
Correlation established with detector glass case temperature
Case temperature monitored accurately (1mK) and used to correct the drift in video counts
Bolometer Sensor : Challenges
Mars Orbiter Mission
Criticalities in Uncooled bolometer Data Analysis
• Thermal Trend is observed in data.
• The sensor output is the function of thermaltrend, Case Temperature, Noise and Surfacefeature.
• The digital signal of the instrument is of theorder of 20-bit (16 bit ADC+4 bit Spectralbinning).
• Signal is buried in the background and noise.
• The EOM HK-Temperature Analysis isattempted to model with Sensor data and nodirect correlation is found.
Functional Diagram of Detector Proximity Electronics
Mars Orbiter Mission
Criticalities, Tcase Correlation (Good Number)
• Dark data
• Video data
Video data is correlated with Tcase.
Mars Orbiter Mission
Criticalities, Tcase Correlation (Poor Number)
• Dark data
• Video data
Tcase is not a good representative of video data/trend.Tcase is not available for each pixel and band separately.
Mars Orbiter Mission
Criticalities, Thermal Trend
• Dark data
• Video data
Video Tcase correction using dark Tcase interpolation isnot appropriate.
Mars Orbiter Mission
TIS Dark data with Operation Chronology
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
30
32
34
36
38
40
42
16.3 16.5 16.6 17.0 17.1 17.5 17.8 20.1 21.1
Ra
w S
D (
DN
)
Raw
Me
an
(D
N)
x 1
00
00
RAW Data with Tcase (°C) Profile Raw Mean
Raw SD
Date and TimeTcase degC
(avg)Dark Mean
RAW DNDark Mean Pro.
DN for 64 FramesDark Mean SD
28-10-15 at103238_dark 17.5 390811 145 40.4
19-07-15 17.1 395006 162 33.9
04-05-15 16.5 402412 154 32.7
23-04-15 17.0 397449 184 31.8
13-03-15 16.6 402633 180 32.8
27-02-15 16.3 405851 169 32.6
Heliocentric phase(05-05-14) 17.8 386700 158 32.0
Geocentric phase(23-11-13) 21.1 348377 226 33.9
Lab data# 20.1 359500 -- 38.3
Mars Orbiter Mission
TIS Data Processing
• Correction for line drops
• Bad pixel correction
• Drift estimation & Drift removal
• Background estimation & Video data compensation for background
• Image enhancement
Mars Orbiter Mission
Correction for line drops• This Raw data is available with line loss information,
• Median filter with window size of 6 element is applied.
Bad pixel correction
• Some of the pixels in Bolometer were
either non responsive or their
response had been erratic.
• Normally, SD counts of such pixels
show high values, this may not be the
case all the time.
• These pixels were identified and
corrected with median filter.
Mars Orbiter Mission
Other Information: Bad pixel correction
List of bad pixels:
This list of bad pixel, is based on the data analysis only, hence can not be taken asreference. The data user can have his own view.
No new bad pixel is observed so far.
All bad pixels were corrected by Median Filter Algorithm.
Image Enhancement for non-uniformity & stipe correction: Gaussian Filter and other approaches.
Band 1 2 3 4 5 6 7 8 9 10 11 12
Bad Pixel
66,147
-- 86,140
69,128,144
62,120
-- 35,158
146 -- -- -- --
Mars Orbiter Mission
Drift estimation & Drift removal
• Accurate extraction of video data from Un-cooled Bolometer sensor,knowledge of temperature of each pixel is required.
• Bolometer output is dominated with background with signal of interestbeing few orders lower, deeply buried in the background.
• In controlled environment the video drift profile matches Tcase drift.
• In such cases the relationship can be modeled and the scene information canbe suitably extracted.
• Drift estimation is carried out for each pixel individually.
Mars Orbiter Mission
Drift estimation & Drift removal
• Drift estimation based on Tcase will not give the desired results :• Video drift and Tcase information do not agree
• Tcase is not true representative for all the pixels
• Data driven approach is more appropriate for such cases.
• Drift estimation is carried out for each band separately, by principle of ‘linear regression’ in time direction.
• To improve the accuracy of the drift estimation, linear regression is carried out over the pixel wise mean remove data.
Mars Orbiter Mission
Background estimation
3D, 2D images of Raw and Processed Deep Space Data
Mars Orbiter Mission
Video data compensation for background
3D, 2D images of Raw and Processed Video Data
Mars Orbiter Mission
Image enhancement
• The resultant processed image having noise that yet to be modeled.
• In order to enhance the image, different techniques were tried.
• A PSF based Gaussian filter is selected.
• The Processed Raw data, subjected to Gaussian smoothing filter.
• Over Sampling Correction and Aspect ratio correction for Mars phase images.
Mars Orbiter Mission
Image Processing Steps with Intermediate Results
Mars Orbiter Mission
Mars Images (23rd Apr 2015)
Mars Orbiter Mission
Mars Images (27th Feb 2015)
Mars Orbiter Mission
Mars Images (13th Mar 2015)
Mars Orbiter Mission
Processed Images Overlaid On Mars Surface
Mars Orbiter Mission
TIS Team
S.S. SarkarManoj KumarAnish SaxenaUSH Rao & teamJalshri Desai & teamOptics teamJitendra SharmaAmul Patel &teamJaya Rathi &teamYogesh Shinde & team Hemant Arora & teamDNVSSN Murty + P&S teamHS Shah & teamRishi Kaushik, QC& Optics QAPFF, Thermo-vacuum & Vibration facilities
Mechanical Workshop team and & All other facilities