airborne geodesy and geophysics for antarctic research · 23/05/2016 · mirko scheinert...

Mirko Scheinert

with contributions by

Franz Barthelmes, Christoph Förste, Markus Rapp, and many more

Airborne Geodesy and Geophysics

for Antarctic Research

Institut für Planetare Geodäsie

Chair of Geodetic Earth

System Research

Faculty of Environmental Sciences, Department of Geosciences, Institut für Planetare Geodäsie, Chair of Geodetic Earth System Research

OUTLINE

HALO The new German research aircraft

GEOHALOGeoscientific HALO flight mission over Italy / Mediterranean Sea

Gravity field in Antarcticaand knowledge of further parameters

ANTHALOGeodetic-geophysical and atmospheric flight mission over Antarctica

RÉSUMÉ


HALO: High Altitude and Long Range Research Aircraft

based on a Gulfstream G550 commercial business jetoperator: German Aerospace Center (DLR)

operation basis: Oberpfaffenhofen / Germany

length 30.9 m

height 7.9 m

wingspan 28.5 m

maximum payload 3,000 kg

maximum altitude 15,500 m

maximum range 8,800 km

max cruise speed 900 km/h

min airspeed 333 km/h


Geoscientific HALO flight mission over Italy and adjacent seasJune 2012

• Mediterranean: characterized by increased georisk earth quakes, tsunamis

• Earth‘s gravity and magnetic fields geoid, geodynamics, tectonic modeling,

bathymetry

• GNSS methods & laser altimetry flight trajectory, altimetry, reflectometry,

scatterometry, occultations

• Scientific performance could be proven

• Independent data @Mediterranean: excellent basis for comparison and

validation

GEOHALO


GNSS antenna in portside

viewport for occultation

and reflectometry measu-

rements (GFZ 1.1)

GNSS antenna array in bottom

aperture for reflectometry and

spectrometry (DLR-GSOC)

gravimeter CHEKAN-AM

(GFZ 1.2)

gravimeter KSS32-M

(BGR)

vector magnetometer Bartington

Mag629 (top) and scalar magne-

tometer Geometrics G823A

(bottom) (GFZ 2.3)

laser distance meter Riegl LD321-3K

(mounted over bottom optical

window) (TU Dresden)


four mission flight days

(& two test flights): 2-12 June 2012

lengths/time 16,150 km @ 33 hours

altitude 3,500 m (10,000 m)

velocity 425 km/h (600 km/h)

GEOHALO


four mission flight days

(& two test flights): 2-12 June 2012

lengths/time 16,150 km @ 33 hours

altitude 3,500 m (10,000 m)

velocity 425 km/h (600 km/h)

example profile ≈1,000 km length

GEOHALO Gravimetry (with CHEKAN-AM)

cf. presentation by Anton

Krasnov (Elektropribor)


Unfiltered signal

(10Hz)

Acceleration from gravity meter Kinematic acceleration (GNSS)



Unfiltered signal

(10Hz)

Filtered signal

(cut-off 200s,

half-wavelength 100s)

Gravimeter recording:

Eötvös effect and normal

gravity subtracted




Unfiltered signal

(10Hz)

Filtered signal

(cut-off 200s,


Difference




Unfiltered signal

(10Hz)

Filtered signal

(cut-off 200s,


Difference

Comparison with

model EIGEN-6C4




flight direction

≈ 1000 km

Gravity disturbance along profiles



Gravity disturbance along profiles

height 10,500 m

speed 660 k/h

height 3,570 m

speed 430 km/h



Conclusion in terms of filtering

• apply the same filter to gravimeter recordings and kinematic

accelerations from GNSS

• filter applied in frequency domain

• search for optimal filter (cut-off wavelength, cut-off steepness

[width of transition band])

here: 100 s half-wavelength

depends on platform dynamics



Results

• RMS of along-track differences to EIGEN-6C4

(d/o 2000, corresponding to 12 km along-track resolution): 2.8 mGal

• RMS of cross-over differences

tie to terrestrial gravity reference, w/o X-over adjustment: 1.7 mGal

tie to EIGEN-6C4, one bias per track: 1.4 mGal

• High consistency, esp. considering that none of mission data were discarded

• Excellent agreement with high-resolution global gravity field model

• Validation of Italian terrestrial gravity database

(Barzaghi et al., 2015, doi 10.1007/1345_2015_45)



Gravity anomaly

model: EIGEN-6C4 (d/o 2190)(Förste et al., 2014)

Gravity Field in Antarctica


Gravity anomaly

Effect of different treat-

ment of polar data gap

in satellite-only models

polar data gap

of GOCE ≈ 1,400 km

difference between

GOCO03S (Mayer-Gürr, 2012) and

EIGEN-6S2 (Rudenko et al., 2014)

(d/o 250)



Free-Air Gravity

Anomaly

Scheinert et al. (GRL, 2016)

• gridded data set

10 km resolution

IAG Subcommission 1.3f

„Gravity and Geoid in

Antarctica“ (AntGG)

SCAR Expert Group on

„Geodetic Infrastructure in

Antarctica“



Complete Bouguer

Gravity Anomaly

Scheinert et al. (GRL, 2016)

• gridded data set

10 km resolution

GRAVSOFT/TC

(Forsberg and Tscherning, 2008)

BEDMAP-2

(Fretwell et al., 2013)

300 km integration radius



Near-surface magnetic surveys in Antarctica(ADMAP – Golynsky et al., 2013)

World Digital Magnetic Anomaly Map(Korhonen et al., 2007)

Magnetic Field in Antarctica


BEDMAP2Fretwell et al. (2013)

Data void areas: inversion based on GOCE 2010 data

Geoid model: EIGEN-GL04C (w.r.t. WGS-84)

Antarctic Bedrock Topography


High-resolution observation of gravity

waves to locate and investigate their

sources and interaction

• Atmospheric gravity waves in the polar

region are drivers of the residual circulation

• Polar mesospheric clouds can be used as

tracer, 2D information available from satellite

observations (CIPS)

• Only few observations exist so far, and are of

inferior quality (range, resolution, precision)

• New airborne system: ALIMA

(laser 372 nm range 100 km,

resolution 1 km / 1.5 min)

previous

observations

Atmosphere Dynamics in Antarctica

10 km

50 km

100 km T, T’, w, w’<T’w’>, nFe

T, T’, n

T, T’, w, w’<T’w’>, n


Timeline

ANTHALO Blue Ice Campaign: December 2017

ANTHALO: November/December 2020

Funding

• DFG Priority Program 1294 „Atmospheric and Earth System Research with

HALO“

• Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences

• German Aerospace Centre, Institute of Atmospheric Physics (DLR-IPA)

• Further national and international partners

ANTHALO


Objectives

• Close gaps in ground-based / near surface potential field data

• Gain consistent, highly accurate observations of

gravity field

magnetic field

surface height and surface/firn properties

thickness and internal layering of the ice sheet

thermal structure and dynamic regime of the middle atmosphere

• Exploit HALO’s long-range capability to connect isolated surveys and

resolve hidden inconsistencies

ANTHALO


Institution Experiment / Instrumentation

GFZ Potsdam

Section 1.2

Scalar gravimeter (CHEKAN-AM)

GNSS and INS for 3D positioning and attitude determination

BGR Hannover Scalar gravimeter (KSS32-M)

TU Dresden /

AWI Geophysics

Scalar and vector magnetometers

TU Darmstadt Strapdown vector gravimetry with INS

GFZ Potsdam Sect. 1.1 /

IEEC Barcelona

GNSS remote sensing

(altimetry, scatterometry and occultation)

TU Dresden Laser altimeter:

Altimetric surface heights and small-scale surface features

AWI Glaciology Ultra-wideband radar (RES):

Internal layers and thickness of the ice sheet

DLR Institute of

Atmospheric Physics

zenith looking lidar system (ALIMA):

Thermal structure & dynamic processes of middle atmosphere

ANTHALO

Cooperation partners and instrumentation


Focus: Closing polar data gap

cf. presentations by Tom Jordan (BAS)

and Arne Olesen/Rene Forsberg (DTU)

Focus: Closing terrestrial data gaps, profiles over

AP and connecting locations of deep ice cores

ANTHALO

Flight planning

~ 150 flight hours in Antarctica


• Geosciences @ HALO Geodetic-geophysical instrumentation onboard jet aircraft

with pressurized cabin: novel application in Europe

• GEOHALO Proof of concept and scientific performance

Kick-off effect for further geodetic-geophysical applications

• Antarctica Largest gap of ground-based and near-surface geoscientific

data, along with polar data gap of satellite gravity mission(s),

esp. GOCE

Internationally coordinated efforts to close these gaps

• ANTHALO Gain highly accurate and consistent observations of a variety

of parameters, esp. potential fields

Exploit HALO’s long-range capability to connect isolated

surveys and resolve hidden inconsistencies

RÉSUMÉ


© Christian Mietner (DLR)

Contact: [email protected]

International Workshop „Airborne Geophysics with Focus on Polar Applications“Dresden, April/May 2017

airborne geodesy and geophysics for antarctic research · 23/05/2016 · mirko scheinert...

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