environmental science from satellites
DESCRIPTION
Environmental Science from Satellites. Jeff Dozier, UCSB. Radiation principles. Atmospheric absorption of solar and infrared radiation. NASA Goddard Institute for Space Studies http://www.giss.nasa.gov. Measurement scale constrained by physics and technology (and money). - PowerPoint PPT PresentationTRANSCRIPT
Environmental Sciencefrom Satellites
Jeff Dozier, UCSB
Radiation principles
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
0.1 1 10 100wavelength (µm)
rad
ian
ce (
Wm
-2µ
m-1
sr-1
)
Sun (5800K)
Scaled for Earth-Sun distance
Earth (288K)
Atmospheric absorption of solar and infrared radiation
NASA Goddard Institute for Space Studies http://www.giss.nasa.gov
Measurement scale constrained by physics and technology (and money)
• Spatial resolution (IFOV/GSD) and coverage (field-of-view/regard)– Optical diffraction sets minimum aperture size
• Spectral resolution () and coverage (min to max)– Narrow bands need bigger aperture, more detectors, longer
integration time
• Radiometric resolution (S/N, NE, NET) and coverage (dynamic range)– Aperture size, detector size, number of detectors, integration time
• Temporal resolution (revisit) and coverage (repeat)– Pointing agility, period for full coverage
5
Spatial, spectral characteristics of some multispectral sensors
1.0 100.4 1.5 153 5 8 120.5 0.80.6 4 6
1
10
100
1000
20
50
200
500
2
5
0.5
wavelength, m
IFO
V,
m
DigitalGlobe(Quickbird)
SPOT (Panchromatic)
SPOT (Multispectral)
Landsat (Panchromatic)ASTER (Multispectral)
Landsat (Multispectral) ASTER (Multispectral)Landsat,
ASTER (Thermal)
Landsat (Thermal)
MODIS (Visible through Infrared)
AVHRR
Aircraft hyperspectral data (AVIRIS)
0.4 m
2.5 m
7
Data rate
2
2
2
bitsswath width velocity # bands band data rate(spatial resolution)
bitskmkm bandssec band Mbitssecm
e.g., Landsat 5
bitskm185 km 7.4 7 bands 8 sec band Mbits85 sec30 m
8
Gulf Stream temperatures from MODIS, May 2, 2001
SeaWiFS image—global chlorophyll July 1997 - Sept 1998
Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE
10
Fractional snow cover, Sierra Nevada, March 7 2004
Surface elevation from interferometric radar
(full resolution image is available from the JPL SRTM image website)
12
Applications: snowmelt modeling(Molotch et al., GRL, 2004)
Snow Covered Area net radiation > 0 degree days > 0
Where:
mq = Energy to water depth conversion, 0.026 cm W-1 m2 day-1
*2 2 *
0 0
0
10.622 0.622(ln / )
2 2a
r q h p aa
RHL de La m C k z z u C RH e
dt T
Melt Flux net q d rR m T a SCA
Surface wetness with AVIRIS, Mt. Rainier, 6/14/96
AVIRIS image, 409, 1324, 2269 nm
precipitable water, 1-8
mm
liquid water, 0-5 mm
path absorption
vapor, liquid, ice
(BGR)
14
Information Lifecycle
• A– Use
– Present
• B– Collect
– Retrieve
• C– Store
– Search
Collect
Store
Search
Retrieve
Use
Present
15
2005 status
• Universal connectivity (except Africa, South America)– Internet
– Web
• Comprehensive analysis environments– GIS, image analysis (ArcGIS, ENVI)
– Matrix manipulation (IDL, MATLAB, …)
• Standard formats– Metadata (FGDC, …)
– Data (XML, GeoTIFF, …)
16
2005 report card• A
– Do complex analyses, many with off-the-shelf tools
• B– Retrieve/publish data from/to
the Web• C
– Can’t find somebody else’s data / they can’t find yours
» How good is your web site?
– Can’t remember what you did / how you did it
» How good are your notes?
– Your conclusions are in the archival literature;where are your data?
» How good are your backups?
17
Major Missing Pieces• Local
– Storage management
» Everything onlineand accessible
– Metadata management
» Everything documented and findable
» Everything connected to where it came from
• Global
– Federation
» Distributed data centers look like a single system
– Service management
» Discover, query, describe, and retrieve information
– Namespace management
» Same names for same things
Digital libraries Personal data centers
18
Earth System Science Workbench: conceptual model
(ESIP—Earth Science Information Partners)
• Experiment– Network of models
» … ingesting / synthesizing data
» … generating products
• Notebook– Persistent storage that can be queried
– Keeps track of all experiments
• Laboratory– Experiment execution environment
20
SST
tu SST
Combining sensors: sea-surface temperature and height
CD-ROM
TeraScan
calibrate,de-cloud,aggregate
extrapolate
SST gridSST “super data”AVHRR imageHRPT downlink
extrapolatecalibrate,aggregate
MGDRcracker
ocean height“super data”
ocean heightgrid
TOPEX points
GOAL:Local and advective components of upper ocean heat balance:
HRPT Data Handling HRPT Gridding
TOPEXGridding
TOPEXData Handling
23
avhrr_handNav
AVHRR telemetry ingest
AHVRR Level 1Bproduct
AVHRR Level 1B:navigatedMulti-channel
sea surfacetemperaturealgorithm
AVHRR Level 0 product
avhrr_copyNav
Hand navigation details
Sea surface temperature (SST)
Copynavigatedimage
SST: navigated
avhrr_sstModel
avhrr_navd_sst
Hand navigationprocedure
avhrr_ingest
avhrr_navd_l1b
avhrr_L0
avhrr_l1b
avhrr_sst
24
# SST experiment wrapper # $L1B is the input Level 1B AVHRR image file# $SST is the output SST image file # run legacy command "nitpix": creates SST image from L1B image $base_temp = 5.0;$temp_step = 0.1;... system("nitpix base_temp=$base_temp temp_step=$temp_step ... $L1B $SST"); # start recording ESSW metadata beginXMLBld($ENV{USER}, "PRODUCTION"); # get metadata for input file $L1B_ID = findSciObjFromFile($L1B);
AHVRR Level 1Bproduct
Multi-channelsea surfacetemperaturealgorithm
Sea surfacetemperature
(SST)
avhrr_sstModel
avhrr_l1b
avhrr_sst
25
# create metadata for SST experiment $exp = createExperimentMetadata("avhrr_sstModel");$exp_step = createExpStepMetadata($exp, "avhrr_sstExpStp"); addValue($exp_step, "avhrr_sstExpStp.base_temp", $base_temp);addValue($exp_step, "avhrr_sstExpStp.temp_step", $temp_step);... saveToDB($exp_step, "avhrr_sstExpStp");closeMetadata($exp_step);
# connect input and output images to experiment registerExperimentInputs($exp, $L1B_ID);registerExperimentOutputs($exp, $SST_ID); # finish recording ESSW metadata endXMLBld();
AHVRR Level 1Bproduct
Multi-channelsea surfacetemperaturealgorithm
Sea surfacetemperature
(SST)
avhrr_sstModel
avhrr_l1b
avhrr_sst
26
27
28
29