Post on 20-Jan-2016
description
transcript
PLANS FOR THE GOES-R SERIES AND COMPARING THE ADVANCED BASELINE
IMAGER (ABI) TO METEOSAT-8
UW-Madison
James J Gurka, Gerald J Dittberner
NOAA/NESDIS/OSD
Timothy J. Schmit,
NOAA/NESDIS/ORA
Mathew M. Gunshor, Kris Karnauskas
Cooperative Institute for Meteorological Satellite Studies (CIMSS)
Madison, WI
June, 2004Prague
2
GOES Users’ Conference I&II Recommendations: Instruments
– Strong Endorsements for Improved:
• Spatial resolution
• Spatial coverage
• Temporal resolution
• Spectral resolution
• Radiometric accuracy
NOTIONAL BASELINE DISTRIBUTED SATELLITE
ARCHITECTURE
NOTIONAL BASELINE DISTRIBUTED SATELLITE
ARCHITECTURE
– Advanced Baseline Imager (ABI)
– Hyperspectral Environmental Suite (HES)
– Solar Imaging Suite (SIS)
– Space Environmental In-Situ Suite
– GOES Lightning Mapper (GLM)
A-SatABISISGLMservice
B-SatHESSEISSservices
A-SatABISISGLMservices
B-SatHESSEISSservices
WEST EAST
The Advanced Baseline Imager:
ABI Current
Spectral Coverage 16 bands 5 bands
Spatial resolution 0.64 m Visible 0.5 km Approx. 1 kmOther Visible/nearIR 1.0 km n/aBands (>2 m) 2 km Approx. 4 km
Spatial coverageFull disk 4 per hour Every 3 hoursCONUS 12 per hour ~4 per hour
Visible On-orbit calibration Yes NoLow-light imaging Yes No
ABI spatial coverage rate versus the current GOES Imager
ABI coverage in ~5 minutes Current GOES coverage in 5 minutes
There are two anticipated scan modes for the ABI:1) full disk images every 15 minutes + CONUS images every 5 minutes +
mesoscale. 2) Full disk every 5 minutes.
Future GOES Imager (ABI) Band
Wavelength Range (μm)
Central Wavelength
(μm) Sample Objective(s)
1 0.45-0.49 0.47 Daytime aerosol-over-land, Color imagery 2 0.59-0.69 0.64 Daytime clouds fog, insolation, winds 3 0.84-0.88 0.86 Daytime vegetation & aerosol-over-water, winds 4 1.365-1.395 1.38 Daytime cirrus cloud 5 1.58-1.64 1.61 Daytime cloud water, snow 6 2.235 - 2.285 2.26 Day land/cloud properties, particle size, vegetation 7 3.80-4.00 3.90 Sfc. & cloud/fog at night, fire 8 5.77-6.6 6.19 High-level atmospheric water vapor, winds, rainfall 9 6.75-7.15 6.95 Mid-level atmospheric water vapor, winds, rainfall
10 7.24-7.44 7.34 Lower-level water vapor, winds & SO2 11 8.3-8.7 8.5 Total water for stability, cloud phase, dust, SO2 12 9.42-9.8 9.61 Total ozone, turbulence, winds 13 10.1-10.6 10.35 Surface properties, low-level moisture & cloud 14 10.8-11.6 11.2 Total water for SST, clouds, rainfall 15 11.8-12.8 12.3 Total water & ash, SST 16 13.0-13.6 13.3 Air temp & cloud heights and amounts
Current GOES ImagersMODIS, Aircraft, etc
ABI Bands
MSG/AVHRR/Sounder(s)
Based on experience from:
7
HES Sounder Capabilities
– Coverage: near full disk/ 1 hr• 10 km footprint
– Useful information 65 deg. from Sat. Sub. Point
– 4 km footprint in Meso/Severe Wx mode
– Rapid Scan option• 1000 x 1000 km in 4 minutes
– Will detect temperature inversions
– Will provide information in cloudy areas• Cloud top characteristics
• Temperature and moisture information above cloud tops
0.625cm-1 1.25cm-1 2.5cm-1
0.625 cm-1 0.625 cm-1
0.6 cm-1 0.6 cm-1
CO2
(T)
Important lines for cloud emissivity and cloud type
Ozone “Traditional Side of
H2O absorption”
CO2 weak H2OCO N2O Temperature
Example 2
Example 1
IR Spectral Coverage (DS or SW/M)
5
HES
HES’
Targeted observations -- look where we need the information
UW/NOAA
Sounder Comparison (GOES-Current to HES-Req)
Coverage Rate CONUS/hr Sounding Disk/hr
Horizontal Resolution
- Sampling Distance 10 km 10 km
- Individual Sounding 30-50 km 10 km
Vertical resolution ~3 km 1 km
Accuracy
Temperature 2 deg. K 1 deg. K
Relative Humidity 20% 10%
Current Requirement
Moisture Weighting Functions
Pre
ssur
e (h
Pa)
Pre
ssur
e (h
Pa)
Advanced Sounder
GOES (18)
1000 1000
100 100
UW/CIMSS
High spectral resolution advanced sounder will have more and sharper weighting functions compared to current GOES
sounder. Retrievals will have better vertical resolution.
GOES LIGHTNING MAPPERGOES LIGHTNING MAPPER• New NOAA Instrument
– Severe Storm Warning Times – Lightning Danger Alerts– Disaster Team Response– Nitrogen Production
• Detects Total Strikes:In Cloud, Cloud To Cloud, And Cloud To Ground– Compliments Today’s Land Based
Systems That Only Measures Cloud To Ground (About 15% Of The Total Lightning)
• Increased Coverage Over Oceans And Lands– Currently No Ocean Coverage,
And– Limited Land Coverage In Dead
Zones
• Parameters– Hemispheric Or CONUS Coverage
– 10 Km Spatial Resolution (1 Km Goal)
EUMETSAT and all are to be congratulated on the successful MET-8 program to a more robust geostationary imager.
Due to Met-8’s improved spectral, temporal and spatial data, Met-8 can be used to help prepare for the next generation U.S. geostationary imager.
If Met-8 is to be to for risk reduction activities for the Advanced Baseline Imager (ABI), then the similarities and differences of the data must be characterized.
Do to the varying center and spectral widths, some ABI/MET-8 bands are very similar, while others less so.
Parameter
Current GOES Imager
MET-8 Future GOES (ABI) Imager
Comments
Visible bands 1 2+1 3 Cloud cover, plant health and surface
features during the day
Near IR bands 0 1 3 Cirrus clouds, Low cloud/fog and fire
detection
Infrared bands 4 8 10 Upper-level water vapor, clouds, SO2,
SST, etc Total number
of bands 5 12 16
Coverage Rate 25 minutes for
full disk 15 minutes for
full disk
Approximately 5 minutes for full
disk
Noise (at 300K) in the IR window
0.15K - 0.10K
No correction has been made for the larger (approximately four times) of the current GOES imager compared to that
of the ABI Spatial
resolutions of the infrared
bands
4-8 km
3 km (with over-sampling)
2 km At the sub-satellite point
Low-light imaging
No No Yes
Comparing the GOES Imager, MET-8 and the ABI
The ABI visible and near-IR bands have many uses.
Visible and near-IR channels on the ABI
Visible and near-IR channels on the ABI
The current GOES has only one visible band.Haze
Cloud
sV
eg.
Cirrus
Part.
size
Snow
, Pha
se
AVIRIS spectra
While there are differences, there are also many similarities for the spectral bands on MET-8 and the Advanced Baseline Imager (ABI). Both the MET-8 and ABI have many more bands than the current operational imagers.
Weighting Functions for the IR channels on the ABI
Weighting functions for the standard atmosphere at a local zenith angle of 40 degrees.
Forward model calculations for the U.S. standard atmosphere (clear-sky) at nadir view comparing the ABI and MET-8
ABI/Met-8 Central wavelength (um)
3.9 3.9
6.19 6.27
6.95
7.34 7.35
8.5 8.7
9.61 9.67
10.35
11.2 10.76
12.3 11.9
13.3 13.3
ABI (K) 286.5 235.4 243.4 254.4 284.5 259.9 286.5 286.9 284.7 269.0 Met-8 (K) 283.9 235.8 254.4 284.3 260.8 286.3 285.6 267.6 ABI-Met-8 (K)
2.6 -0.4 - 0.0 0.2 -0.9 - 0.6 -0.9 1.4
These brightness temperature differences are not errors, just differences due to varying spectral widths and centers that should be understood.
ABI v. MSG – Visible, near-IR
Comparing the impact of spectral response differences for the 0.8 m, and 1.61 m bands from the Advanced Baseline Imager and the Meteostat Second Generation (MET-8) satellites is accomplished for the visilble bands by convolving the various spectral response functions with high spectral resolution AVIRIS (aircraft) data.
Below is a spectral plot of a clear and cloudy scene over the SCAR-B scene.
ABI v. MSG – Visible, near-IR
The 0.6 and 1.6 m bands are very similar, while the 0.8 m band is more different between the two instruments due to the differing center wavelength.
ABI v. MSG – 0.8 m
ABI v. MSG – 1.6 m
MSG v. current GOES Imager – 4 m
AIRS data cannot be used to simulate the MSG 4 m band due to the wide spectral region coved by the MSG extends beyond the data for AIRS. So, a calculated spectra was used.
GOES-12 BT: 288.3K MSG BT: 284.5K GOES-MSG: 3.8K
GOES-12 and MSG 3.9 m SRF and night-time spectra.
ABI v. MSG – Some IR bands
Comparing the impact of spectral response differences for (some of) the IR from the Advanced Baseline Imager and the Meteostat Second Generation (MET-8) satellites can be accomplished by convolving the various spectral response functions with high spectral resolution AIRS (NASA satellite) data.
Below is a sample of a SRF at one AIRS spectra in the IR window region.
Some bands can not be processed due to spectral gaps in the AIRS coverage. Of course the AIRS is coarser spatial resolution compared to the MET-8 or what ABI will be.
Below is a sample simulated from AIRS for the MET-8 IR window region. This case is from March 19, 2004 at approximately 1:30 UTC.
11 um image
Some of these differences may be due to spectral gaps in the AIRS data.
7.3 m difference
Some of the difference between the convolved AIRS and forward calculations may be due to the amount of ozone
9.6 m difference
11 m difference
Fairly small differences
12 m difference
Fairly small differences—largest in warmer (clear) regions
13 m difference
Fairly large differences due to the varying spectral widths
Met-8 data -- displayed at SSEC
Summary
- Met-8 is leading the way with an advanced multi-spectral geostationary operational imager. Met-8 data will be used to prepare for the ABI.
- ABI and Met-8 have a number of similar bands, although due to spectral response differences, care must be taken when comparing the various bands.
- Some ABI/MET-8 bands are expected to be more similar (0.6, 7.35 and 8.7 m)
- While other ABI/MET-8 bands are expected to be somewhat different (0.8, 3.9 and 13.3 m)
- We look forward to the continuous nature of the high-spectral IASI instrument so more of the ABI bands can be simulated due to the removal of various spectral gaps.