NPOESS VIIRS: Design, Performance
Estimates and Applications
Carl F. Schueler, Shawn W. Miller and Jeffery J. Puschell
Raytheon Space and Airborne Systems, Goleta, California
Thomas F. Lee , Steven D. Miller, Jeffrey D. Hawkins, F. Joseph Turk
and Kim Richardson
Naval Research Laboratory, Monterey, California
John Kent
Science Applications International Corporation, San Diego, California
The 14th International TOVS Study Conference, 25-31 May 2005, Beijing, China
1
Overview
•The National Polar-orbiting Operational Environmental Satellite
System (NPOESS) Visible Infrared Imaging Radiometer Suite (VIIRS)
will offer dramatic spatial, spectral, and radiometric performance
improvements over current operational capabilities
• NOAA Advanced Very High Resolution Radiometer (AVHRR) offers
1 km nadir spatial resolution in 5 spectral bands
• The Defense Meteorological Satellite Program (DMSP) Operational
Line-scanning System (OLS) offers near constant contrast 1.8km
day-night cloud imaging and visible and thermal imagery
2
VIIRS
•VIIRS offers 22 band spectroradiometry comparable to NASA’s
MODerate-resolution Imaging Spectroradiometer (MODIS).
• On NPP and NPOESS
• 3000 Km Swath
• Day-night cloud imagery (constant contrast 750 m resolution)
• 4:1 better edge-of-scan spatial resolution than AVHRR or MODIS
3
NOAA AVRRR Contributions to VIIRS Subpoint Spatial
Resolution
Wavelength
AVHRR
VIIRS
• .63 µm
Imagery, Clouds, Snow, Dust
• .86 µm
Terrain, vegetation, water
• 1.6 µm
Snow, Cirrus Properties
• 3.7 µm
Fires, Low Clouds, SST
• 10.8 µm
Images, Cloud height, SST
• 11.8 µm
(11.5 µm)
1.1 km
4
0.37 km
Volcanic Ash, Split Window
VIIRS System Provides Excellent
Environmental Data Records (EDRs)
Imagery (with four ARRs)
Sea Surface Temp
Aerosol Optical Thickness
Aerosol Particle Size
Suspended Matter
Cloud Cover/Layers
Cloud Effective Particle Size
Cloud Optical Thickness
Cloud Top Height
Cloud Top Pressure
Cloud Top Temperature
Albedo
Land Surface Temperature
Vegetation Index
Snow Cover/Depth
Surface Type (ST)l
Fresh Water Ice(Sea Ice ARR)
Ice Surface Temperature
Ocean Color/Chlorophyll
Sea Ice Characterization
Active Fires (ST ARR)
Precipitable Water
Cloud Base Height
Net Heat Flux
Soil Moisture
IORD/TRD Threshold
IA
IIA
IIB
IIIB
IORD/TRD Objective
• VIIRS System Design based on integrated Sensor and Algorithms
• Engineering Development Unit (EDU) approaching integration
• EDR Science Algorithms developed, documented, and publicly released by
Raytheon Technical Services Company (RTSC) Information Technology and
5 Scientific Services (ITSS)
VIIRS VIS/NIR & IR Bands
V IIR S , M O D IS , F Y -1 C , A V H R R
VIIRS, MODIS
C O 2
O 2
O 3
H 2O
O 2
H 2O
H 2O
H 2O
O 2
H 2O
H 2O
C O 2
M 1
N a d ir
0 .7 4 2 x 0 .2 5 9
End of Scan
1 .6 0 x 1 .5 8
M 2
0 .4 4 5
0 .7 4 2 x 0 .2 5 9
1 .6 0 x 1 .5 8
M 3
0 .4 8 8
0 .7 4 2 x 0 .2 5 9
1 .6 0 x 1 .5 8
M 4
0 .5 5 5
0 .7 4 2 x 0 .2 5 9
1 .6 0 x 1 .5 8
I1
M 5
0 .6 4 0
0 .6 7 2
0 .3 7 1 x 0 .3 8 7
0 .7 4 2 x 0 .2 5 9
0 .8 0 x 0 .7 8 9
1 .6 0 x 1 .5 8
M 6
I2
M 7
0 .7 4 6
0 .8 6 5
0 .8 6 5
0 .7 4 2 x 0 .7 7 6
0 .3 7 1 x 0 .3 8 7
0 .7 4 2 x 0 .2 5 9
1 .6 0 x 1 .5 8
0 .8 0 x 0 .7 8 9
1 .6 0 x 1 .5 8
0 .7 4 2 x 0 .7 4 2
0 .7 4 2 x 0 .7 4 2
VIS/NIR FPA
0 .7
PV HgCdTe (HCT)
Silicon PIN Diodes
D N B
M 8
M 9
I3
M 10
M 11
I4
M 12
M 13
1 .2 4
1 .3 7 8
1 .6 1
1 .6 1
2 .2 5
3 .7 4
3 .7 0
4 .0 5
LWIR
S/MWIR
C C D
PV HCT
6
H o r iz S a m p le I n t e r v a l
(k m D o w n tra c k x C ro s s tra c k )
W avele n g th
(µ m )
0 .4 1 2
Band
N o.
M 14
M 15
I5
M 16
8 .5
1 0 .7
1 1 .4
1 2 .0
5
63
50
13
D r iv in g E D R s
R a d iance
R ange
L ty p o r
T ty p
O c e a n C o lo r
A e r o s o ls
O c e a n C o lo r
A e r o s o ls
O c e a n C o lo r
A e r o s o ls
O c e a n C o lo r
A e r o s o ls
Im a g e ry
O c e a n C o lo r
A e r o s o ls
A t m o s p h e r ic C o r r 'n
N D VI
O c e a n C o lo r
A e r o s o ls
Im a g e ry
Low
H ig h
Low
H ig h
Low
H ig h
Low
H ig h
S in g le
Low
H ig h
S in g le
S in g le
Low
H ig h
V a r.
4 4 .9
155
40
146
32
123
21
90
22
10
68
9 .6
25
6 .4
3 3 .4
6 .7 0 E -0 5
0
0
0
0
0
0
0
0
.7
.7
.3
.7
.7
.3
.7
.7
4
4
7
4
4
7
4
4
2
2
1
2
2
1
2
2
x
x
x
x
x
x
x
x
0
0
0
0
0
0
0
0
.7
.7
.3
.7
.7
.3
.7
.2
7
7
8
7
7
8
7
5
6
6
7
6
6
7
6
9
1 .6 0
1 .6 0
0 .8 0
1 .6 0
1 .6 0
0 .8 0
1 .6 0
1 .6 0
x 1 .5 8
x 1 .5 8
x 0 .7 8 9
x 1 .5 8
x 1 .5 8
x 0 .7 8 9
x 1 .5 8
x 1 .5 8
C lo u d P a r t ic le S iz e
C ir r u s /C lo u d C o v e r
B in a r y S n o w M a p
S n o w F r a c t io n
C lo u d s
I m a g e r y C lo u d s
SST
SST
F ir e s
S
S
S
S
S
S
S
in g le
in g le
in g le
in g le
in g le
in g le
in g le
Low
H ig h
0
0
0
0
.7
.7
.3
.7
4
4
7
4
2
2
1
2
x
x
x
x
0
0
0
0
.7
.7
.3
.7
7
7
8
7
6
6
7
6
1 .6 0
1 .6 0
0 .8 0
1 .6 0
x 1 .5 8
x 1 .5 8
x 0 .7 8 9
x 1 .5 8
C lo u d T o p P r o p e r t ie s
SST
C lo u d Im a g e r y
SST
S
S
S
S
in
in
in
in
g
g
g
g
le
le
le
le
5 .4
6
7 .3
7 .3
0 .1 2
270 K
270 K
300 K
380 K
2
3
2
3
7
0
1
0
0
0
0
0
K
K
K
K
I
0.74km
DNB
I
0.74km
7
1.2km
SNR predicted and specified at worst-case edge of scan:
~60% better nadir SNR and finer spatial resolution
1.6km
1.1km
0.75km
0.75km
M
Fine-Resolution
Imaging ‘I’ Bands
0.74km
Day-Night
Band ‘DNB’
M
DNB
0.74km
DNB
0.74km
I
0.74km
Finer Sampling, Spatial
Resolution & Better Sensitivity
M
1.6km
ModerateResolution
(“Radiometric”)
‘M’ Bands
AVHRR VISIBLE SIMULATION
Nadir
8
Edge of Scan
VIIRS VISIBLE SIMULATION
Nadir
9
Edge of Scan
San Diego – MODIS Edge
10
San Diego – MODIS Nadir
11
GOES versus MODIS
12
Quality of Subsectors
MODIS
VIIRS
H
H
13
2300 km
3000 km
VIIRS value to forecasters
multiplied by efficient data delivery!
ƒ 95 % of data delivered within
28 min to central processing
stations
ƒ Average delivery time 10.5 min
ƒ Current prototypes using MODIS
have latency 2-3 hours
14
NexSat WebPage: Audience and Scope
Publicly accessible demonstration of Satellite
Products over the continental United States:
1.Simulate future NPOESS capabilities in
public forum
2.Near-realtime display of products, some
not previously available (e.g., nighttime
visible)
15
NexSat: Web Design
16
NexSat: 250m City Zooms
17
NexSat: Dust Storms
Dust Enhancement
True Color
Lake
Tahoe
Nevada
California
Dust Plume
18
NexSat: Aircraft Contrails
“Racetrack”
flight pattern
19
NexSat: Fire Detection
20
NexSat: Cloud/Snow Discrimination
•
•
•
21
Complex snow/cloud
scenes during winter in
Southwest Asia
Difficult to distinguish
clouds from snow in
single visible and
window-infrared
channels
The ability to determine
the presence of cloud
over a snow field is
useful to targeting,
surveillance,
navigation, etc.
Snow
Snow
Clouds
Low
Clouds
High Clouds
Clouds
DayNight Band (DNB)
Constant Resolution
ƒ Purpose: Replicate OLS capability but with
updated technology and improvements
ƒ 0.5 -- 0.9 µm broadband visible
ƒ Detectors are aggregated to produce nearconstant resolution
ƒ More detectors aggregated near nadir for high
SNR; fewer aggregated near edge for lower
SNR
22
DNB “Constant Contrast”
Three Gains
High
Medium
Low
Relative Gain
119,000
477
1
ƒ Improves SNR at low radiances
ƒ All pixels are imaged with all three gains
ƒ Onboard processing selects the most sensitive gain setting
without saturation for transmission to the ground
ƒ Goal is “constant contrast” imagery
23
DMSP (F14) Terminator Image
AFWA
24
Full Moon
25
DMSP OLS
NGDC Poster
26
No Moon
27
Full Moon
98% full, 48.1º Elevation
28
VIIRS Improvement
for DNB
DMSP OLS
1.
64 Gray shades
2.
2.2 km Field of View
3.
Limited Pixel Expansion
4. Numerous Image Artifacts
29
NPOESS VIIRS
64 X = 4096 Gray shades
0.75 km Field of View
No Pixel Expansion
Artifacts Eliminated
Lights over Korea
Image and data processing by NOAA’s National Geophysical
Data Center. DMSP data collected by US Air Force Weather Agency
30
OLS Lightning Detection
http://www.nrlmry.navy.mil/nexsat_pages/nexsat_home.html
31
Near-Realtime Polar
Products from NexSat
http://www.nrlmry.navy.mil/nexsat_pages/nexsat_home.html
32
Conclusions
ƒ VIIRS adds advanced capability not available from MODIS
ƒ NPOESS will truly be a forecaster’s system
ƒ Constant-Contrast/Constant-Resolution Data will produce vivid,
information-rich images for DNB
ƒ Preservation of footprint size will facilitate much more usable images
ƒ VIIRS fine channels replicate the capability of AVHRR
ƒ Many products in addition to EDRs
ƒ True color capability preserved for VIIRS
33