Uncertainty Budget of the Airborne Imaging Spectrometer APEX

35 Pages·2016·7.87 MB·English

by  Andy Hueni

Uncertainty Budget of the Airborne Imaging
Spectrometer APEX
CALCON 2016, Logan (UT)
A. Hueni (UZH)
E. Woolliams (NPL)
Outline
Testing and Acceptance
2008 - 2010
Operational Flights (Exploitation)
2009 - …
Flight OPs, PAF
Development,
Data Analysis &
General
Suspicions
Blueprint Deviations: Sensor Model
2010-2011
2012 - …
Uncertainty Budget
2014 - …
APEX Introduction: Optics & Electronics
Wavelength
950 nm –
2500 nm
SWIR Detector
Sofradir
30um
(Follow-on of this
model now used in
Sentinel 2)
VNIR CCD
E2V, 22.5um
Back illuminated
Wavelength: 380 nm – 1000 nm
APEX Introduction: Layout &
Areas of Uncertainty
Smearing
→ L
SWIR
Electronics
→ L
Pressure
→ λ
Dichroic
Coating
→ L
Temperature
→ (λ), L
A short history …
2008: First Flight 2008-…: Lab Calibration 2009: Calibrated Imagery
A short history …
2010/2011: Spectral Shifts
D'Odorico, P., Guanter, L.,
Schaepman, M. E. and Schläpfer, D.
(2011). "Performance assessment of
onboard and scene-based methods
for Airborne Prism Experiment
spectral characterization." Applied
Optics 50(24): 4755-4764.
A short history …
2011-… : APEX Calibration Information System
• EAV (Entity-Attribute-
Value) Paradigm based
metadata storage
• Stores frames and
metadata
• Can also store single
spectra and cubes (multi-
layered frames).
• Stores provenance data
Hueni, A., Lenhard, K., Baumgartner, A.,
& Schaepman, M. (2013). The APEX
(Airborne Prism Experiment -Imaging
Spectrometer) Calibration Information
System. IEEE Transactions on
Geoscience and Remote Sensing, 51,
5169-5180
A short history …
2012: Spectral Shifts in Lab
using Monochromator and
pressure modifications
SWIR spectral shift due to
200mbar pressure change:
A short history …
2013-2014: Optics of APEX and N Pressure
2
Dispersion is a
linear function
of N density
2
and therefore
roughly a
function of
aircraft flight
level.
N
Hueni, A., Schlaepfer, D., Jehle, M., Schaepman, M.
2
E., 2014. Impacts of Dichroic Prism Coatings on
Radiometry of the Airborne Imaging Spectrometer
APEX. Appl. Opt. 53(24), 5344–5352.
A short history …
2013-2014: Dichroic Coating and Results due to Pressure Change