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WHAT WE PROVIDE

We can schedule SeaWiFS onboard LAC (1-km resolution) coverage for stations on your cruise if they are not already covered by one of our HRPT stations (if you are not sure whether or not you are covered by an HRPT station, feel free to request coverage; our software will determine whether it is necessary). Typical LAC coverage is for a 30-second interval, which corresponds to 180 scan lines (approximately 200 kilometers along track at nadir).

Since the schedule is uploaded to the SEASTAR satellite as much as 7 days in advance, we need to have position information at least one week in advance to ensure that your LAC coverage is scheduled. If you are not sure exactly what your position will be, please give us your best estimate and the margin of error; we will try to ensure coverage. LAC Scheduling is not automatic. Even if you have requested overflight predictions and pictures for a location, you must explicitly request LAC scheduling, being as specific as possible, in order to ensure coverage.

HOW DOES LAC SCHEDULING WORK?

Approximately 10 minutes of LAC scheduling time per day are available for onboard LAC recording; the SeaWiFS scheduling software apportions time according to priority (as set by the SeaWiFS Calibration/Validation group), amount of LAC coverage time requested, and feasibility. There are two types of targets: sites (which includes ships, moorings and fixed locations) and regions. Both types of targets may be prioritized, but all site targets take precedence over any regional target. This is why giving us a specific date, latitude, and longitude rather than a region increases the chances that your LAC coverage will be scheduled.

When selecting LAC coverage for a site, it is not critical to have an exact location. A typical LAC request is for 30 seconds of coverage, which is approximatly 200 km of latitude.

To request LAC scheduling or overflight predictions of a region, please use this format:

Region
Site Description Begin Date End Date North Lat South Lat East Lon West Lon
South Pacific 04/14/1998 04/18/1998 -5.00 -20.50 -175.25 -160.50

To request LAC scheduling or overflight predictions of a site, please use this format:

Site
Site Description Begin Date End Date North Lat South Lat East Lon West Lon
MOBY 04/14/1998 04/18/1998 20.838 20.838 -157.237 -157.237

ROUTINELY SCHEDULED CAL/VAL LAC SITES

For internal sensor calibration and validaion, we always schedule LAC coverage for several SeaWiFS Calibration/Validation sites.

DEFAULT SEAWIFS LAC COVERAGE REGIONS

The five default regions are always in the schedule. These have a lower priority and are covered only if the higher priority calibration/validation sites and regions scheduled do not use up all LAC recording time.

Region Name North Lat South Lat East Lon West Lon
JGOFS Southern Ocean -50.0 -78.0 -160.0 160.0
Antarctic LTER -62.0 -68.0 -64.0 -75.0
Equatorial Pacific 3.0 -3.0 -80.0 170.0
African Gulf 10.0 -10.0 15.0 -15.0
West African Coast 25.0 5.0 -15.0 -35.0

ROUTINELY SCHEDULED CAL/VAL LAC SITES

For internal sensor calibration and validaion, we always schedule LAC coverage for several SeaWiFS Calibration/Validation sites.

Site Latitude Longitude
MOBY 20.838 -157.237
Venice Tower 45.314 12.508
HOTS (Hawaii) 22.750 -158.000
PlyMBODy 50.217 -4.083
BATS & BTBM 31.833 -64.167
Abbott's IDS program -60.000 -160.000
Caribbean site 10.500 -64.667

REQUESTING LAC SCHEDULING

Please be advised this service is only available to authorized users of SeaWiFS data (see the section on SeaWiFS Authorized Users.

You may request LAC scheduling On-Line

OR

Send LAC scheduling requests to schedule@oceancolor.gsfc.nasa.gov. LAC scheduling requests are generally processed within 24 hours of receipt.

Curator: OceanColor Webmaster

Authorized by: gene carl feldman
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Updated: Wednesday, 28-Nov-2007 08:47:32 EST
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