1. MODIS Airborne Simulator (MAS),
MODIS/Aster Airborne Simulator (MASTER)
(mas.arc.nasa.gov, masterweb.jpl.nasa.gov)
50 spectral channels from VIS to IR (grating spectrometer, 4 focal planes), 50 m spatial resolution (nadir at ground, from ER-2 at 20 km altitude), 16 bit data system
MAS vs. MASTER: same data system but different optical configurations
MAS: VIS to 14 µm, flown on ER-2 in over 30 field campaigns
MASTER: VIS to 12 µm, variable scan speed for different a/c altitudes, flown on B200 King Air, ER-2, WB-57, DC-8
NASA Facility instrument supported by the Ames Airborne Sensor Facility (J. Myers)
Engineering and maintenance
Field support and data processing (L1B)
Calibration/Characterization Lab: radiometric cal (light sources, integrating spheres, diffusers, NIST traceability), spectral cal from UV to IR, environmental test chamber
Level-2 products provided by PI investigators only

2. Example MAS Sc Cloud Retrievals
SAFARI-2000, 14 Sept 2000, ER-2 Flight Track 10
S. Platnick, M. D. King, G. T. Arnold, G. Wind
MODIS Terra, 1010 UTC
Flight Track #10 (~1120 UTC)

3. SAFARI-2000, 14 Sept 2000, ER-2 Flight Track 10
northern part of track off Angola
Cloud
Mask
Optical
Thickness
Effective
Radius
RGB
Phase
1119 UTC
• Using a version of the Collection 5 operational MODIS retrieval code. Just implemented and still under test.
• The dual color bar is of course better suited for scenes with water and ice phase (typical in MODIS imagery), but this example only has water clouds. Didn’t have time to modify the visualization for a single color bar.
• Note there are a few retrievals that have an optical thickness but no effective radius, usually in broken cloudy regions. These are termed “partial retrievals” in MODIS and indicate a pixel for which the observations can’t be matched to models (cloud mask false positive, partly cloudy pixel, incorrect phase, incorrect surface albedo, etc.). These pixels are ignored in MODIS Level-3 aggregations.
• Other retrieved quantities include: water path; cloud top temperature and pressure; uncertainties for tau, re, and water path; multilayer cloud flags
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