Mars Orbiter Mission - Space Applications Centre TIS_Instru… · Mars Orbiter Mission 7-13 µm,...

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


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


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


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)


Instrument Design & Development: EO Module Optics


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


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


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


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


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


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.


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.


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.


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


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


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


Criticalities, Tcase Correlation (Good Number)

• Dark data

• Video data

Video data is correlated with Tcase.


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.


Criticalities, Thermal Trend

• Dark data

• Video data

Video Tcase correction using dark Tcase interpolation isnot appropriate.


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


TIS Data Processing

• Correction for line drops

• Bad pixel correction

• Drift estimation & Drift removal

• Background estimation & Video data compensation for background

• Image enhancement


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.


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 -- -- -- --


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.


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.


Background estimation

3D, 2D images of Raw and Processed Deep Space Data


Video data compensation for background

3D, 2D images of Raw and Processed Video Data


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.


Image Processing Steps with Intermediate Results


Mars Images (23rd Apr 2015)


Mars Images (27th Feb 2015)


Mars Images (13th Mar 2015)


Processed Images Overlaid On Mars Surface


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

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