O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Oscar Chic and Jordi Font, ICM, CMIMA-CSIC, Barcelona

Real Time Satellite Data Management for Operational Oceanography.

The Example of a Satellite Receiving Station

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Earth observation orbiting satellites(scanning radiometers type)

• Wide alongtrack swath (depending on sensor)• Mostly sun-synchronous• Data recorded and transmitted in real time• Land stations receiving data when satellite over

horizon (multiple channels)• Spatial resolution decreasing from nadir • Real time or delayed mode processing• Geometric/radiometric corrections, spatial windows,

archiving, distribution

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

CMIMA Barcelona station(Mediterranean Centre for Marine and

Environmental Research - CSIC)

• Installed autumn 2001• Data-Tools system• Fully operational

August 2002• Web access to images• Spatial coverage

Açores – Israel

Denmark - Sahel

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

CMIMA Barcelona station

Barcelona sea front

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

CMIMA system elements

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

• Polar orbiting (99°, 700-800 km, helio-syncron, L-band (1.7 GHz), 100

min period, 2 passes/day, 5000x2400 km mid-latitude)

• Satellites received at ICM

NOAA (12->17) AVHRR (visible, infrared for SST) + other sensors

SeaWiFS (ocean colour)

FengYun1-C/D (not of much use over ocean)

SPOT4/5 vegetation (land applications, 1 km resolution)

• Future

MODIS? (new hardware needed)

Satellites and sensors

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Data Acquisition

• Programmed satellite passes

• Orientable parabolic antenna automatically pointing to satellite

• One acquisition computer + one data processing and archiving

•10 bits HRPT telemetry (High Resolution Picture Transmission)

• Snapshot created and used as a background image in acquisition PC

• Small metadata file created.

• Backup of all the raw data in DVD+R and DAT media.

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

WXtrack pass prediction for viernes, 2004 ene 16 Station in ICM, located at 2.20°E, 41.39°N Pass elevation at least 15.0 degrees for at least 180 seconds ________________________________________________________ N/S Satellite A O S L O S Mins Elev Long UTC S NOAA 16 02:18:27 02:27:41 10 73° 5° S NOAA 12 03:54:07 03:59:29 6 21° 19° S NOAA 16 04:01:38 04:04:41 4 17° 342° S NOAA 12 05:32:43 05:40:57 9 47° 355° S NOAA 15 06:25:34 06:34:04 9 50° 9° S FENGYUN 1C 07:05:33 07:14:36 10 64° 358° S NOAA 14 07:16:08 07:24:44 9 44° 11° S NOAA 15 08:06:40 08:12:02 6 22° 346° S FENGYUN 1D 08:11:38 08:20:43 10 52° 9° S NOAA 14 08:57:25 09:04:07 7 26° 347° S FENGYUN 1D 09:53:42 09:59:46 7 23° 345° S NOAA 17 10:48:50 10:57:39 9 73° 360° S ORBVIEW 2 (S 11:31:21 11:36:03 5 21° 18° N NOAA 16 12:07:15 12:11:51 5 19° 21° S ORBVIEW 2 (S 13:07:52 13:14:57 8 40° 354° N NOAA 16 13:45:12 13:54:18 10 62° 358° N NOAA 12 15:13:52 15:21:27 8 35° 13° N FENGYUN 1C 16:52:40 17:00:08 8 31° 15° N NOAA 12 16:53:55 17:01:02 8 30° 349° N NOAA 15 17:46:16 17:55:07 9 79° 4° N FENGYUN 1C 18:32:58 18:41:07 9 36° 351° N NOAA 14 18:41:53 18:51:06 10 82° 3° N FENGYUN 1D 19:39:26 19:48:56 10 86° 2° N NOAA 17 20:31:51 20:37:57 7 24° 18° N NOAA 17 22:10:25 22:18:43 9 44° 354° N ORBVIEW 2 (S 22:36:12 22:41:30 6 24° 16°

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

SST Data Processing

• Semi-automated system to process every AVHRR pass over Western Mediterranean in near-real time (every hour) in order to compile a database of sea-surface temperature images at the best spatial resolution (1.1 km).

• The system has routines for automatic navigation and cloud-masking.

• After processing (split-window equation), navigated and annotated SST images are available on WWW only 90 minutes after the start of acquisition.

• During processing a complete metadata file and snapshots of each channel are created. In metadata file, information like % cloud of ROI (region of interest). In the future this will be in a database allowing queries.

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Metadata file (example)filename : 2004-01-19-0652-Noaa15.n10satellite : noaa-15start_time : 06:54:54pass_date : 2004/01/19orb_elements : 0.8210517 0.8357317 7e-05 0.0010789 0.1829084 0.7750761 0.2736992sunelev : 0satazim : 278sunazim : 0satelev : 87subtrack : 34sublat : 41sublon : 2duration : 00:13:53coverage : 100center_lat : 37.6352center_lon : 0.5555pixel_width : 0.7675pixel_height : 1.1141total_width : 2822.9829total_height : 4258.8244upper_left_lat : 57.3772upper_left_lon : -15.0720upper_right_lat : 51.0181upper_right_lon : 27.7357lower_left_lat : 20.4353lower_left_lon : -17.8290lower_right_lat : 16.4808lower_right_lon : 8.6096center_sun : -2.68center_sat : 90.00sat_sub_lat : 37.6351sat_sub_lon : 0.5561daytime : nightPercent_cloud = 74

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Extracció de dadesdes de telemetría.

Calibracióradiomètrica1

Metadata6

Navegar2Treure angleselevats, núvols,reflexe del sol3

Càlcul de latemperatura4

Zona d' interès7

Georeferenciació5

Mapa deTemperatura

8

1 Visible channels 1 i 2 -> % albedo. Infrared channels 3a/b,4 i 5 -> brightness T. First georeferenciation with ephemerides/orbital elements.

2 Small errors on satellite internal clock and on horizon tracking require a finer georeferenciation. Windows correlation.

3 Satellite zenital angle > 53º --> bad data. Cloud filtering (different daytime and nightime procedure).

4 MCSST algorithm (McClain,1985) SST = A*T4 + B*(T4-T5) + C*(T4-T5)*(sec(sza)-1) + D*(sec(sza)-1) + E 5 Mercator projection with 1.1 km resolution on the square area (45N, 34N) x (9E, 6O)

6 Metadata file example

7 Selected area

8 SST

SST Processing Scheme

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Sequential tests applied to all pixels.

1. if (satellite_zenith_angle > ref_angle (53º)) then bad_value

2. i (3x3) if (max(i-center) > threshold) then cloud cloud>sear

3. if (night) i (3x3) if (mean(Tb3-Tb4) < threshold) then cloud

4. if (ch2 > threshold) then cloud

5. if (Tb4 < threshold) then cloud

6. if (solar_ref_angle<min_solar_ref_angle)

then bad_value

IMPORTANT: Some clouds are not detected and appear on the image as anomalously cold areas. This is due to very dry atmosphere, low clouds, sun glint, noise in channel 3 …

Discarding pixels (mainly clouds)

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Full process: from raw data to SST map21 January 2004 21h54 NOAA-17

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Quality ControlReal time control

• Selection of passes depending on elevation angle (area coverage, enough spatial resolution)

• Application of validated routines to build maps

• Few years ago it was obtained a statistical RMS error lower than 0.6 comparing SST images with in-situ termosalinograph temperature.

Delayed mode control

• Visual inspection of data quality

• We are studying to perform an automatic quality control using moored buoys off the Spanish coast (Puertos del Estado).

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Bad data records

1. Satellite ocultation by nearby building

2. Transmission failure

3. Problems in scan motor

4. Undetermined problems with old NOAA-12

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Left: SST (standard and zebra palettes). Up: Quick-look

Temperature

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

1. SST

2. Raw channels (HDF)

3. DCS/Argos

4. TOVS (atmospheric data)

Total precipitable water Total ozone

avhrr_ch2 avhrr_ch4

NOAA products

Air temperature

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

• ICM Barcelona is one of the 92 SeaWiFS Direct Readout Ground Stations (8 on research vessels). Real time decription possible for short periods under specific request

• Format conversion • Telemetry raw format n10 (encripted Data-Tools)• n10 s10 (OGP Orbview key software, every 15 days)• s10 SeaWiFS-L0 (NASA standard, SeaStarLevel0 soft)• L0 L1a (data sent to NASA, NASA software)

• Generation of quicklooks and data offered to SeaWiFS Authorized Data Users (http://seawifs.gsfc.nasa.gov/SEAWIFS/LICENSE/checklist.html).

• Management of Barcelona and R/V Hespérides data archive

• Future: automatic generation of chlorophyll a concentration maps

IMPORTANT: “Just in time for the Christmas holidays, NASA is pleased to announce that a new contract has been signed with ORBIMAGE to acquire one additional year of SeaWiFS data starting on 24 December 2003 under the same terms and conditions as the previousagreement. ” Gene Carl Feldman 24/12/2003

SeaWiFS Data Management

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Processing scheme and quicklook

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

SeaWiFS July 2002 chlorophyll a concentration

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

ICM SATPROCES Web Sitehttp://satproces.cmima.csic.es

Web map• Introducción / Home Page • Estación Receptora de imágenes de Satélite

(ERS) • Archivo de Datos • Satélites visibles • FAQ • Novedades

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Examples of operational use

R/V Hespérides Fine tunning of hydrographic surveys of mesoscale circulation guided by infrared images provided in real time by an on-board satellite receiving station (October 1996)

Alboran Sea

Algerian basin

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MFSPP - Observing systemMFSPP - Observing system

Overall NRT Basin Scale Observing System

VOS

XBT temperature700 m profiles

12 m.n. along track1 day delay

along track sea level anomalies

1 day delay

T/P and ERS2 Weekly SST, three days delay

NOAA-AVHRR

M3A buoy

3 hours data, 1 day delay

ARGOS

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

Satellite data sets in NRTMFSPP - Observing systemMFSPP - Observing system

Sea Level Anomaly

Sea Surface Temperature

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

MFSPP - FCST Basin ScaleMFSPP - FCST Basin Scale

The weekly forecasting system

ECMWF ANECMWF AN ECMWF FCECMWF FC

SSTSSTSLASLA

XBTXBT

J-7J-14 J-5 J-4 J-3 J-2 J-1

Wed

WedThu Fri Sat Sun Mon

Tue Thu Fri WedThu Fri

J+1 J+2 J+7 J+8 J+9JWed

FORECASTFORECASTRELEASERELEASE

O. Chic, J. Font, MAMA 5th meeting, Malta, January 2004

This dramatic image of black smoke plumes over Baghdad was acquired the morning of March 31, 2003, by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard NASA’s Terra satellite.

The End