1 An Introduction to POES Data and Products 28 February 2002 Last modified 13-Feb-02 by Stan Kidder...

1

An Introduction toPOES Data and Products

An Introduction toPOES Data and Products

28 February 2002Last modified 13-Feb-02

by Stan Kidder (CSU/CIRA)by Stan Kidder (CSU/CIRA)andand

Patrick Dills (UCAR/COMET)Patrick Dills (UCAR/COMET)

Contributors and Reviewers:

Anthony Mostek (NWS/COMET)Sherwood Wang (COMET)Scott Bachmeier (UW-Madison/CIMSS)Brian Motta (CSU/CIRA/RAMM Team)Kevin Schrab (NWS-Western Region)

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I. Introduction

II. POES Orbits and Coverage

III. Examples of POES Products

IV.Real-time POES Data Access

V. Summary

VI.Questions

Outline

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I. Introduction

• What is POES ?

• Why use POES data ?

• What are the problems (from an operational forecasting standpoint) with POES data ?

– “At what time can I expect fresh data over my area of responsibility ?“

– “Why are there gaps in coverage over the Pacific during certain 3 to 4 hour time intervals ?”

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What Is POES?• GOES = Geostationary Operational Environmental

Satellite, so…

• POES = Polar-orbiting Operational Environmental Satellite – often shortened to Polar Operational Environmental Satellite

• Two main POES types:– NOAA

– DMSP

• Several semi-operational polar-orbiting satellites:– QuikSCAT

– TRMM

– Terra (current) and Aqua (2002) MODIS imager

I. Introduction

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I. Introduction

Why Use POES Data?

• Channels/products not available on GOES

– Microwave observations

– Active sensors (e.g., QuikSCAT)

– More visible/infrared channels, even UV

• Higher spatial resolution and less noise (because POES are a lot closer to the earth than GOES – 850 km vs. 35,000 km)

• Polar satellites view the poles/high latitudes

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What Are The Problems (operational considerations)

With POES Data?

I. Introduction

• Infrequent observations — two per satellite per day in the midlatitudes and tropics (but more near the poles)

• It’s hard to tell when an observation was made

• Data are sometimes delayed

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Satellite orbits in a circle about the center of the earth Gets up to about 82° latitude – close, but not right over the poles Earth turns under the satellite The satellite always moves west Coverage:

• twice daily near equator (once ascending, once descending)• several times at lat >50 degrees

Complete animation at: http://www.comet.ucar.edu/class/POES_2001/poes_ani_link.htm


The Basic POES Orbit24-hr loop

Equator Crossings07:30 Local Time

(Descending)19:30 Local Time (Ascending)

Polar Crossings07:55 Local Time (Descending)19:55 Local Time (Ascending)

POES AM (NOAA-15) – 24 Hour Coverage POES AM (NOAA-15) – 24 Hour Coverage

North Pole View

33-FRAME LOOP

http://www.comet.ucar.edu/class/POES_2001/poes_ani_link.htm










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Basic Image Loop


12-hr composite~13-hr (8 orbit) AMSU

composite loop

Equator Crossings07:30 Local Time

(Descending)19:30 Local Time (Ascending)

POES 12 Hour Coverage

Since the satellite always moves west, you can tell whether it is ascending (going north) or descending (going south).

Sometimes more than one orbit comes in at one time

Sometimes orbits are missing or delayed

~ 100 min/orbit

From AWIPS 12-FRAME LOOP

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Single POES (NOAA-16) – most recent pass only ~14 orbits in 24 hour period Coverage – at least twice daily, several times at lat >50 degrees 2 to 3 consecutive orbits twice daily at some higher latitude locations


24-hr AVHRR IR Loop Polar Coverage

First

14-FRAME LOOP

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Two POES (i.e. NOAA-15 and 16)

• Smaller scan angles narrower orbit swaths larger gaps between adjacent orbits

• Interactive animation at left: http://www.comet.ucar.edu/class/POES_2001/2poes_link.htm

Two orbiter coverage


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Time is sometimes carved into the image

Satellite makes one orbit (360°) in about 100 min; i.e., it goes about 3.6°/min, or about 10° in 3 minutes.

With a knowledge of which way the satellite is moving and how fast it is moving, one can estimate when it observed a particular point.


Time NOAA -15 and -16 AMSU TPW

A B C D E F G H I J K L

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Time NOAA -15 and -16 AMSU TPW Polar Stereo Composite

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Time


With a knowledge of which way the satellite is moving and how fast it is moving, one can estimate viewing time at a particular point.

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With a knowledge of which way the satellite is moving and how fast it is moving, one can estimate viewing time at a particular point.


Time

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Data are recorded on tape, transmitted to a ground station, and then processed into products

We have two ground stations: one at Wallops Island, VA, and one at Fairbanks, AK

Uneven spacing of these stations causes data “blinds” and delayed data


Data Blinds

Most recent NOAA -15 & -16

orbits

First9-FRAME LOOP

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Two ground stations: one at Wallops Island, VA, and one at Fairbanks, AK (Lannion, France not operational)

All raw data are also made available via direct broadcast to local receivers (HRPT for imagery, DSB for sounding data, APT)


Data Broadcast – NOAA(recorded and direct)

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DMSP data are recorded and relayed to satellite ops centers in Suitland and Colorado Springs;

then relayed to AFWA, FNMOC, and shipboard and tactical terminals via communication satellites

for processing into environmental product records


Data Broadcast – DMSP

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About half of the AMSU data are received in 2 hours or less About three fourths of the AMSU data are received in 4 hours or

less Perhaps 5% of the AMSU data are 12 hours old when received


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Because the satellites are sunsynchrounous, the data blinds occur at the same times each day

Long delays between 0 and 6 UTC are NOAA–15 and –16 happen with ascending orbits past (west of) Fairbanks, AK


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Programs are available to track the satellites

• Sample output from WXtrack ‘freeware’ software - http://www.satsignal.net/


http://www.satsignal.net/



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Satellite #25338 : NOAA 15

Element Set Number: 356 (Orbit 17354)

Element Set Epoch : 14Sep01 19:35:42.443 UTC (2.4 days ago)

Orbit Geometry : 801.94 km x 818.45 km at 98.597 deg

Propagation Model : SGP4

Ground Location : Anchorage, AK, USA

Time is shown in : LOC (-8.00 h)

OVERPASS SUMMARY:

Date (LOC) Time (LOC) of Azimuth at Peak Height Vis Orbit

Rise Peak Set Ris Pk Set Elev at Pk

Sun 16Sep01 07:54:11 08:00:31 08:06:52 23 80 136 14.1 794 DDD 17382

09:34:07 09:41:40 09:49:22 19 103 184 54.6* 794 DDD 17383

11:14:19 11:21:36 11:29:01 18 302 228 42.5* 792 DDD 17384

12:54:07 13:00:28 13:06:48 22 325 269 16.4 789 DDD 17385

14:33:15 14:38:31 14:43:46 34 350 305 9.0 786 DDD 17386

16:10:54 16:16:17 16:21:41 61 15 329 9.8 784 DDD 17387

17:47:52 17:54:28 18:01:05 99 38 339 19.5 785 DDD 17388

19:26:03 19:33:28 19:41:01 141 63 342 54.8* 787 DDD 17389

21:06:15 21:13:40 21:21:13 186 263 341 40.5* 788 VVV 17390

22:49:33 22:55:05 23:00:53 237 285 335 10.0 787 VVV 17391

Satellite #25338 : NOAA 15

Element Set Number: 356 (Orbit 17354)

Element Set Epoch : 14Sep01 19:35:42.443 UTC (2.4 days ago)

Orbit Geometry : 801.94 km x 818.45 km at 98.597 deg

Propagation Model : SGP4

Ground Location : Anchorage, AK, USA

Time is shown in : LOC (-8.00 h)

OVERPASS SUMMARY:

Date (LOC) Time (LOC) of Azimuth at Peak Height Vis Orbit

Rise Peak Set Ris Pk Set Elev at Pk

Sun 16Sep01 07:54:11 08:00:31 08:06:52 23 80 136 14.1 794 DDD 17382

09:34:07 09:41:40 09:49:22 19 103 184 54.6* 794 DDD 17383

11:14:19 11:21:36 11:29:01 18 302 228 42.5* 792 DDD 17384

12:54:07 13:00:28 13:06:48 22 325 269 16.4 789 DDD 17385

14:33:15 14:38:31 14:43:46 34 350 305 9.0 786 DDD 17386

16:10:54 16:16:17 16:21:41 61 15 329 9.8 784 DDD 17387

17:47:52 17:54:28 18:01:05 99 38 339 19.5 785 DDD 17388

19:26:03 19:33:28 19:41:01 141 63 342 54.8* 787 DDD 17389

21:06:15 21:13:40 21:21:13 186 263 341 40.5* 788 VVV 17390

22:49:33 22:55:05 23:00:53 237 285 335 10.0 787 VVV 17391

Text based tracking program

• Sample output from NASA’s Satellite Overpass Predictor - http://earthobservatory.nasa.gov/MissionControl/overpass.html


http://earthobservatory.nasa.gov/MissionControl/overpass.html









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A great place to start learning (or continue learning) about POES products are the COMET Modules, available on the Web at meted.ucar.edu/modules.htm

http://meted.ucar.edu/modules.htm






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Vegetation

Visible (channels 1 and 2 – 0.6 and 0.9 microns)

Sensitivity to surface characteristics

• Vegetation, soil type, suspended silt (i.e. upper Chesapeake Bay)

Suspended silt as seen with visible ch. 1

Suspended silt as seen with visible ch. 1

Water appears dark/clear in

ch. 2

Water appears dark/clear in

ch. 2

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Infrared window channels – near IR (3.7 micron ch. 3a) and longwave IR (11 micron ch. 4) combined

‘Fog/stratus product’


1 km Resolution Fog/Stratus

GOES-8 4km NOAA-14 1km

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1.6 µm – AK Example

2-FRAME FADE with next

• 1.6 m (ch.3a)

1.6 micron channel (ch. 3b) compared with VIS• Enhanced land/water contrast, more reflection from land• Greater solar reflection by cloud water and ice, than by snow and ice

cover and bare ground• Enhanced ability to distinguish clouds from snow and ice cover

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• Visible (ch1)

1.6 micron channel (ch. 3b) compared with VIS• Enhanced land/water contrast, more reflection from land• Greater solar reflection by cloud water and ice, than by snow and ice

cover and bare ground• Enhanced ability to distinguish clouds from snow and ice cover

1.6 µm – AK Example

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• Can you separate clouds from snow and ice on the ground ?

1.6 µm Cloud, Snow & Ice Detection – Manitoba, CA

• Visible

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• Enhanced discrimination of clouds (water and ice) over snow and ice cover


• 1.6 m

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• Beginning with NOAA-16, the 3.7 m channel is available nighttime only

and the 1.6 m channel takes its place during daytime.


• 3.7 m

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• 11 micron window channel assists with identifying high clouds

• 11 m


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• False-color composites can depict a range of detection capabilities in a single image

• Vis/1.6/11m R/G/B


green – bare ground

dk blue – water

blue – forest/forest and snow mixed

pink – snow and ice cover

whiteish yellow – low clouds

light pink to light blue – ice clouds


dk blue – water





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• Can you find the cloud boundaries ?

1.6 µm Cloud, Snow & Ice Detection – North Dakota

• Visible

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• 1.6 m

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• 3.7 m

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• 11 m


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• Vis/1.6/11m R/G/B



dk blue – water






dk blue – water





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• Can you distinguish any clouds from the recent snowfall ?

1.6 µm Cloud, Snow & Ice Detection – Northeast U.S.

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• 1.6 m


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• 3.7 m


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• 11 m


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• Vis/1.6/11m R/G/B



dk blue – water



yellow – low clouds



dk blue – water



yellow – low clouds


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Infrared channels – near and longwave IR• Nighttime 3.7 (ch3) compared to 11micron (ch4)• Thin cirrus clouds warmer/more transparent in 3.7 micron channel• Water clouds appear colder in 3.7 micron channel


3.7 µm Cloud Phase

• 3.7 m (ch3)

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3.7 µm Cloud Phase

• 11 m (ch4)“clean” IR window

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3.7 µm Cloud Phase

• 3.7/11 mbrightness temp.

difference product

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Infrared channels – near IR and IR window• Infrared channel difference (ch3 & 4) – “fog/stratus product”• Good for nighttime water vs. ice cloud discrimination


Cloud Phase Loop

• “fog/stratus product”• clouds in motion

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Infrared channels – near IR and IR window• Infrared channel difference (ch3 & 4) – “fog/stratus product”• Good for nighttime water vs. ice cloud discrimination


• “fog/stratus product”• clouds in motion

Cloud Phase Loop

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Fire Detection

Infrared channels 3 and 4 (3.7 and 11micron) in combination 3.7 micron channel sensitive to ‘sub-pixel’ hot spots Fire detection (natural and man-made)

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Fire Detection


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Fire Detection


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Infrared window channels

Used for ash plume detection

Color enhancement (ch 4 image) improves detection of cold ash plume

Channel 4 minus 5 difference product helps discriminate the ash plume from high level clouds when ash plume extends above tropopause and is semi-transparent (optically thin).


Volcanic Ash• AVHRR ch.4

• ch. 4-5 (11-12m) difference products

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Channel 4 minus 5 (11 – 12 micron) difference product

Product will become more important as (12 micron) channel is discontinued on GOES after GOES-12.

• 4-day composite


Volcanic Ash

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Infrared windowchannels –11 and 12 micron

Sea surfacetemperatures

Real-time products at:http://www.osdpd.noaa.gov/PSB/PSB.html#LIST


Sea Surface Temperature

http://www.osdpd.noaa.gov/PSB/PSB.html#LIST







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QuikSCAT Winds (quasi - operational)

Available on AWIPS and the Internet Becomes “operational” product with NPOESS (~2008) For data and training resources, see entries on the “Internet

Links Page” at: http://www.comet.ucar.edu/class/POES_2001/ref_links.htm

http://www.comet.ucar.edu/class/POES_2001/ref_links.htm






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SSM/I Wind Speed

SSM/I ocean wind speed is combined with wind direction information from model pressure analysis/forecast to derive wind vectors (at right).

Wind speed valid between 0 and 50 m/s

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Precipitable Water (TPW)

Microwave – AMSU and SSM/I• Similarities and differences related to:

– swath coverage, scan geometry, polarization

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Cloud Liquid Water

Microwave

• CLW – useful for assessing aviation hazards and precipitation production

First7-FRAME LOOP

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Rain Rate

Microwave• RR for AMSU is based on ice water path and RR relation derived from MM5

cloud model data• Valid between 0 and 30 mm/hour

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• TPW • CLW

• Rain rate

• WV 6.7m


POES Compliments GOES

Microwave – multiple product views

• TPW, CLW, RR, & GOES Water Vapor (AWIPS view)

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Snow cover is displayed as “yes” or “no”

Ice cover is displayed as % coverage between 30-100%


AMSU Snow Cover and Sea Ice

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NESDIS SAB (Synoptic Analysis Branch) combines all available GOES (GOES, GMS, Meteosat), POES, and surface obs snow and ice data to generate daily 25km Northern Hemisphere snow and ice map.

Snow and ice analysis used by NWS as operational input to NWP models

Microwave observations of snow and ice provide useful information through clouds, particularly during winter season darkness.


Multi-Sensor Snow Cover & Sea Ice http://www.ssd.noaa.gov/PS/SNOW/index.html

7-FRAME LOOP

http://www.ssd.noaa.gov/PS/SNOW/index.html







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Adding water to dry land lowers brightness temperatures, particularly at lower microwave frequencies

Lower and higher frequency channel brightness temperature information is combined to assess soil moisture


Soil Wetness

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POES profiles the atmosphere where GOES can not• for cloudy field of views• higher latitudes and regions not covered by GOES

Blue dots = clear, gray and white dots = cloudy


Soundings Through Clouds

http://poes.nesdis.noaa.gov/posse/










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IV. Real-time POES Data Access

• AWIPS and LDAD

• Servers (McIDAS)

• Web-sites

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POES data and AWIPS LDAD• Menu snapshot & product examples – “SSM/I Rain Rate”

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POES data and AWIPS LDAD• Menu snapshot & product examples – “Global SST”


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POES data and AWIPS LDAD• Menu snapshot & product examples – “AMSU TWP”


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Servers and Internet Links

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Internet links page• http://www.comet.ucar.edu/class/POES_2001/ref_links.htm

Sea ice

AMSU-B 89GHz

Snow cover

SSM/I TPW

Ocean Winds

AVHRR Imagery

Fires


Servers and Internet Links







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V. Summary• POES are not geostationary, so their data take

some getting used to – where is spacecraft now and when will it be overhead ?

• POES offer channels/products/perspectives not available from GOES

– Microwave observations

– Active sensors (e.g., QuikSCAT)

– More visible/infrared channels

– Higher spatial resolution

– Polar satellites view the poles/high latitudes

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Future Teletraining Sessions

• Emphasis on product applications

– Include imaging, sounding, and derived product based applications

– Regional focus (i.e. Northern Pacific, Alaska, Canada, tropical latitudes)

May 2002 – “Using POES Microwave Data to Assess Rainfall Potential for Coastal Storms”

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VI. Questions?

The ugly guy you’re asking questions of

[email protected]

1 An Introduction to POES Data and Products 28 February 2002 Last modified 13-Feb-02 by Stan Kidder...

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