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TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

The suitability of historical optical satellite imagery for investigations of the cryosphere

Tino Pieczonka1, Nicolai Holzer1, Juliane Peters1, Tobias Bolch1,2,

Manfred F. Buchroithner1

1

Technische Universität Dresden, Institut für Kartographie

2

Universität Zürich, Geographisches Institut

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Introduction

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Cartosat-1 2007 Aerial imagery 1984 Corona 1970

The cryosphere has changed tremendously during the last decades

We have to know the past in order to understand the presence.

Elevation difference of all HMA glaciers 2003 – 2009 based on I CESat

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Introduction

Gardner et al. (2013), Science

c l e a r m a s s l

• s

s clear mass loss

heterogeneous mass changes

clear mass loss

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

1973 – 2000 – 2011

Why optical? Why historical? What means historical? Which kind of changes of the cryosphere can be determined and how?

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Introduction

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Historical

Pertaining to history or past events ... historical images Pertaining to analysis based on a comparison among several periods of development of a phenomenon

Historic vs. historical

Historic refers to what is important in history ... Historical refers to anything concerned with history or the study of the past ... historic Corona mission

• > A car can be considered as historical when it reaches its 30th vintage

anniversary

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Introduction

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Data KH-4 Corona, KH-7 Gambit, KH-9 Hexagon, AVHRR

Historical satellite imagery

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Study Region

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Study Region

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Study Region

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Study Region

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Study Region

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Data

Data characteristics

KH-4 KH-7 KH-9 AVHRR

First launch 1959 1963 1971 1978

• Geometric. res.

1.8-7.6 m 0.6 – 1.2 m 6-9 m 1.1 km Radiometric res. 8 Bit 8 Bit 8 Bit Spectral res. Panchromatic Panchromatic Panchromatic Multispectral (Red, NIR, MIR, TIR, TIR) Coverage 15 x 210 – 42 x 580 km

• ca. 20 x 150 km

250 x 125 km e.g. 3000 x 500 km Preprocessing Rectification Georeferencing Rectification Georeferencing Rectification Georeferencing Calibration Classification Rectification Georeferencing

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Forward (FWD)

• approx. 60% overlap

Aft (AFT)

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Camera KH-4

KH-4 Corona

Initial objectives: Gathering information about the military strenght of the former Soviet Union Panoramic distortion plus motion

Sohn et al. (2002) Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Multitemporal DTM

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Co-Registration

Excursus: Co-Registration Tilts vs. Shifts (+ vertical offset)

Tilt ... Indicated by areas with slope angle ≤ 10°

• > Trend surface to eliminate spatial trend

Shift ... Indicated by areas on gentle slopes ≥ 10°

• ≤

30°

• > Iterative process based on an analytical relationship

between slope angle, aspect and measured elevation differences (Nuth & Kääb, 2011)

Pieczonka et al. (2013), RSE

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

SPOT5 – KH-9 SPOT5 – SRTM3

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Results KH-4

Everest Region

DEM Comparison Cartosat-1 – KH-4B Corona (2007 – 1970)

Bolch et al. (2011), The Cryosphere Pieczonka et al. (2011), ISPRS

Glacier mass loss: almost 0.6 km³ Glaciers thinning: 0.37± 0.27 m a-1 Specific mass balance:

• 0.32± 0.08 m w.e.a-1

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Camera – KH-7

KH-7 Gambit

Monocamera system

• > random stereoscopic coverage

KH-7 vs. KH-4:

High resolution 77 inch focal length (cf. 24 inch KH-4) telescopic strip camera system ... large area of coverage and improved ground resolution (< 1 m vs. 8 m) 18 000 panchromatic and 230 color images acquired

• > only few of them in stereo

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Results KH-7

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Wiemann et al. (in prep.)

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Glacier Length Changes (Kailash region)

KH-7 Gambit (05/12/1964)

• vs. mapped glacier out-

lines from orthorectified SPOT5 imagery of 06/11/2010

Results KH-7

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Langa Tso / Rakas Tal lake level changes:

Ortho-KH-7 Gambit-1 imagery of 05/12/1964 (background image) vs. Ortho-SPOT-5 imagery of 06/11/2010 2009 (mapped

• utlines)

Ganga Chu at Xiongbacun (Lake Manasarovar / Mapam Yumtso)

KH- 7 196 4 Google 2013

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Lake Level Changes (Kailash region)

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Camera KH-9

KH-9 Hexagon

Camera design of KH-9 comparable to that of LFC (Surazakov and Aizen, 2009)

• > 23x46 cm frame, 30.5 cm focal length
• > 1058 reseau crosses vs. 45 (LFC), four fiducials vs. 12 (LFC)

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Preprocessing KH-9

KH-9 Hexagon

Reconstruction of interior image geometry by use of reseau grid coordinates Basic assumptions: Cross spacing 1 cm, centre cross undistorted Correction of film distortion based on 2nd

• rder polynomial

Distortion vectors from actual to theoretic reseau grid coordinates Bicubic interpolation Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

1987-03-24 1987-07-22

Results KH-9

Length Changes 1976-2005 (Nyainqentanglha/ Tibet) Zhadang: 225 ± 45m (~ 8m/ a) 480 ± 45m (~ 17m/ a) 430 ± 45m (~ 15m/ a) 125 ± 45m (~ 4m/ a)

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Results KH-9

1999 (SRTM3) – 2009 (SPOT5)

Glacier Volume Change (Tomur Region)

1976 (KH-9) – 2009 (SRTM3)

Pieczonka et al. (2013), RSE

Mass budget 1976-2009

• 0.35 ± 0.15 m w.e./ a

Mass budget 1999-2009

• 0.23 ± 0.19 m w.e./ a

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

AVHRR Calibration

AVHRR (Advanced Very High Resolution Radiometer)

Raw images with DN are transferred into albedo and radiances respectively Sensor degradation of channel 1 and 2 in orbit has to be corrected using a regression formula Temperatures are calculated from radiances employing the inverted Planck´ s radiation equation Non-linearities of radiance measurements in channel 4 and 5 are adjusted using corresponding error values

calibrated AVHRR scene (25.09.1998, band combination: 4-3-2) Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

AVHRR Classification

AVHRR Classification

Dichotomous multi-channel classification scheme to distinguish snow, no snow and clouds (Voigt et al., 1999) Based on differences in surface temperature and albedo 6 steps [e.g. max. surface temperature, min. snow temperature, albedo] Thresholds of each step are adapted to respective season

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Results AVHRR

AVHRR Snow Classification (Spring and Summer) 1987-03-24 1987-07-22

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

TU Dresden >> Faculty of Environmental Sciences>> Institute of Cartography

Conclusions

Tino Pieczonka et al. The suitability of historical optical satellite imagery for investigations of the cryosphere

Conclusions

• Knowledge especially for the last decade significantly improved by using historical

satellite images

• Careful co-registration is required in order to determine reliable glacier mass budgets
• On average, significant glacier mass loss across High Mountain Asia since the 1960s
• Ground truth and in-situ measurements of glacier mass balance, snow, firn and ice

density as well as the influence of debris cover are of key importance to improve the remote sensing based results.

• Combining AVHRR with MODIS a time series of snow cover can be derived starting in

the 1980s

• More studies are needed to extend the coverage both by space and

especially in time

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Thank you for your attention Any questions? tino.pieczonka@tu-dresden.de nicolai.holzer@tu-dresden.de juliane.peters@tu-dresden.de