Synthetic Aperture Radar (restricted data) SAR

Beam Mode

The beam mode that was used to acquire/process this dataset. The valid beam modes are:

  • ScanSAR Wide - 500 x 500km
  • ScanSAR Narrow - 300 x 300km
  • Extended Low - 170 x 170km
  • Wide - 150 x 150km
  • Standard - 100 x 100km
  • Extended High - 75 x 75km
  • Fine - 50 x 50km

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Beam Position

The beam mode position used to acquire this dataset. The characters used for valid beam positions are: 1 through 7, A and B.

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Beam Mode - Position

A combination of beam mode and position used when acquiring the data for this dataset. The valid beam mode position values are:

  • Extended High - 75 x 75km position 1
  • Extended High - 75 x 75km position 2
  • Extended High - 75 x 75km position 3
  • Extended High - 75 x 75km position 4
  • Extended High - 75 x 75km position 5
  • Extended Low - 170 x 170km position 1
  • Fine - 50 x 50km position 1
  • Fine - 50 x 50km position 2
  • Fine - 50 x 50km position 3
  • Fine - 50 x 50km position 4
  • Fine - 50 x 50km position 5
  • ScanSAR Narrow - 300 x 300km position A
  • ScanSAR Narrow - 300 x 300km position B
  • ScanSAR Wide - 500 x 500km position A
  • ScanSAR Wide - 500 x 500km position B
  • Standard - 100 x 100km position 1
  • Standard - 100 x 100km position 2
  • Standard - 100 x 100km position 3
  • Standard - 100 x 100km position 4
  • Standard - 100 x 100km position 5
  • Standard - 100 x 100km position 6
  • Standard - 100 x 100km position 7
  • Wide - 150 x 150km position 1
  • Wide - 150 x 150km position 2
  • Wide - 150 x 150km position 3

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Calibration

Indicates if the data in the given dataset was calibrated. The valid values are:

  • CALIBRATED = Data was calibrated
  • UNCALIBRATED = Data was not calibrated
  • UNKNOWN = Data may or may not have been calibrated

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Data Usage Guidance/Restrictions

This Datatype is currently restricted to authorized users. For guidance on how to become an authorized user, send a request to the CLASS Help Desk.

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Dataset Name

The name of the SAR dataset archived at CLASS. The name has the following format: Post-Processing-Center.Spacecraft-Unique-ID.Processing-Site-Code.Year-Day.Start-Time.Location- 1.Location-2.Unique-Qualifier with each qualifier defined below:

Qualifier Details
Post-Processing-Center A fixed field of three characters identifying the post-processing center. The recognized character group is:
NSS = NOAA/NESDIS - Suitland, Maryland, USA
Spcaecraft-Unique-ID Two characters identifying the unique satellite which acquired the data:
R1 = Radarsat-1
E1 = ERS-1
E2 = ERS-2
Processing-Site-Code Two-character code identifying where the data was processed. Recognized character groups are:
AF = Alaska SAR Facility
GT = Gatineau, Canada
TR = Tromso, Norway
WF = West Freugh, UK
Year-Day e.g. D04104, where "D" identifies this group as a Julian day delimiter, "04" identifies the year in which the spacecraft began recording the data and "104" identifies the Julian day on which the spacecraft began recording the data.
Start-Time e.g. T135544, where "T" identifies this group as a start time delimiter. "135445" denotes 13 hours 55 minutes 44 seconds UTC (to the nearest second) and represents the time at which spacecraft recording began.
Location-1 Seven character field indicating the latitude and longitude of the image's upper left corner, where "P" indicates positive and "N" indicates negative, e.g. P61N155, indicates a positive 61 degree latitude and a negative 155 degree longitude.
Location-2 Seven character field indicating the latitude and longitude of the image's lower right corner, where "P" indicates positive and "N" indicates negative, e.g. P56N146, indicates a positive 56 degree latitude and a negative 146 degree longitude.
Unique-Qualifier One character used to distinguish between different versions of datasets mapping to the same name, e.g. A on first occurrence, B on second occurrence, C on third, etc.

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Dataset Size

The size in kilobytes of the file to be delivered to the user.

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End Date/Time

The UTC date and time corresponding to the end of the coverage of the given dataset. Format is yyyy-mm-dd hh:mm:ss.fff where fff is the fraction of a second in milliseconds.

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Inventory ID

A unique numerical ID assigned to the data set for CLASS inventory purposes.

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Node

The ascending node refers to that portion of the orbit during which the satellite is heading northward. Descending refers to the southbound portion.

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Orbit Number

The number of the orbit (revolution) in which the satellite was traveling when the data was acquired.

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P1 Latitude

Latitude of the lower left corner

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P1 Longitude

Longitude of the lower left corner

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P2 Latitude

Latitude of the upper left corner

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P2 Longitude

Longitude of the upper left corner

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P3 Latitude

Latitude of the upper right corner

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P3 Latitude

Longitude of the upper right corner

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P4 Latitude

Latitude of the lower right corner

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P4 Longitude

Longitude of the lower right corner

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Pixel Spacing

The pixel spacing for the dataset. Possible values are:

  • 3.13
  • 6.25
  • 12.50
  • 25.00
  • 45.00
  • 50.00
  • 100.00
  • 300.00
  • 400.00

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Processing Site

The site where the data was processed. The valid processing sites for SAR data are:

  • AF = Alaska SAR Facility
  • GT = Gatineau, Canada
  • TR = Tromso, Norway
  • WF = West Freugh, UK

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Product Type

The valid product types for SAR data are:

  • Geo-Coded
  • Geo-Referenced

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Satellite

The valid satellites for SAR data are:

  • R1 = Radarsat-1
  • E1 = ERS-1
  • E2 = ERS-2

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Spatial

Refers to the geographic area of interest to the user. This section of the search page allows the user to define the geographic area of interest.

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Start Date/Time

The UTC date and time corresponding to the beginning of the coverage of the given dataset. Format is yyyy-mm-dd hh:mm:ss.fff where fff is the fraction of a second in milliseconds.

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Temporal

Refers to the time span of interest to the user. This section of the search page allows the user to define the range of dates/times of interest.

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UTC

Coordinated Universal Time (UTC) is the international time standard. It is the current term for what was referred to as Greenwich Meridian Time (GMT). Zero (0) hours UTC is midnight in Greenwich England, which lies on the zero longitudinal meridian. Universal time is based on a 24 hour clock, therefore, afternoon hours such as 4 pm UTC are expressed as 16:00 UTC (sixteen hours, zero minutes).

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