Shortname: OMAERUVG

Longname: OMI/Aura Aerosol Extinc & Absorp Opt Depth Daily L2 Global
0.25deg Lat/Lon Grid

PFS Version: 1.0.35

Date: 23 January 2007

Author(s): Peter Leonard (ADNET)

PGE Version: 1.0.35

Lead Algorithm Scientist: Omar Torres (UMBC)

Lead Algorithm Developer: Peter Leonard (ADNET)

Lead PGE Developer: Peter Leonard (ADNET)

PGE Developer(s): Peter Leonard (ADNET)

Description: \>

This document specifies the format of the Ozone Monitoring Instrument
(OMI)

OMAERUVG product, which is the daily Level 2G (L2G) gridded data product
that

corresponds to the OMAERUV product. The latter is the U.S. aerosol
extinction and absorption optical depth orbital Level 2 (L2) swath data
product

(Reference 1).

The L2G product contains 24 UTC hours of L2 product subsetted onto a

longitude-latitude grid.

An OMI L2G day is defined to be the 24 hours that lie between UTC times
of

0 hours, 0 minutes, 0 seconds and 23 hours, 59 minutes, 59.999999
seconds.

The L2G product contains the data for all L2 \"scenes\" that

1\) have observation times that lie within the L2G day in question,

2\) have centers that lie within the L2G grid cell in question, and

3\) are \"good\".

A \"good\" OMAERUV L2 scene is defined as one that has

i\) a solar zenith angle that is less than or equal to 70.0 degrees, and

ii\) an UV aerosol index that is not equal to the missing value.

The adopted L2G grid is a 0.25-degree by 0.25-degree grid in longitude
and

latitude. The dimensions of this grid are 1440 by 720. The origin of the

grid is at lower left. That is, the grid cell at coordinates (1, 1)

is centered at (longitude = -179.875 , latitude = -89.875),

and the grid cell at coordinates (1440, 720)

is centered at (longitude = 179.875 , latitude = 89.875).

The adopted L2G grid is consistent with the document entitled
\"Definition

of OMI Grids for Level 3 and Level 4 Data Products\" by J.P. Veefkind et
al.

(Reference 2).

The L2G product currently excludes L2 data collected in spatial and
spectral

zoom modes.

Each \"good\" L2 scene is mapped onto only one L2G grid cell.

The number of L2 scenes that are mapped onto a given L2G grid cell can
range

from 0 to 12, and the corresponding data are stored in an additional
dimension

of the grid.

The L2 data are not averaged or weighted in any way in the L2G product.

The product is stored as one HDF-EOS 5 grid file, and has a size of 75
MB.

The format of the L2G product files is consistent with the document
entitled

\"HDF-EOS Aura File Format Guidelines\" by C. Craig et al. (Reference
3).

Global Metadata:

\- Metadata Name: EndUTC

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: PGE

Description: \>

UTC at the end of the L2G granule in \"YYYY-MM-DDT23:59:59.999999Z\"
format.

\- Metadata Name: FirstLineInOrbit

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 1

Maximum Value: 1700

Data Source: PGE

Description: \>

The first line number in each L2 orbit that contributes to the L2G
granule.

\- Metadata Name: GranuleDay

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 31

Data Source: PGE

Description: The day of the month at the start of the L2G granule.

\- Metadata Name: GranuleDayOfYear

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 366

Data Source: PGE

Description: The day of the year at the start of the L2G granule.

\- Metadata Name: GranuleMonth

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 12

Data Source: PGE

Description: The month of the year at the start of the L2G granule.

\- Metadata Name: GranuleYear

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 2000

Maximum Value: 2099

Data Source: PGE

Description: The (four-digit) year at the start of the L2G granule.

\- Metadata Name: HDFEOSVersion

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: HE

Description: \>

The version of HDF-EOS 5 used in production. Example is
\"HDFEOS_5.1.8\".

\- Metadata Name: InstrumentName

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: OMI

Data Source: PGE

Description: Actual is \"OMI\" (see Section 6.1 of Reference 3).

\- Metadata Name: LastLineInOrbit

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 1

Maximum Value: 1700

Data Source: PGE

Description: \>

The last line number in each L2 orbit that contributes to the L2G
granule.

\- Metadata Name: NumberOfLinesMissingGeolocation

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 1

Maximum Value: 1700

Data Source: PGE

Description: \>

The number of lines in each L2 orbit that are missing geolocation
(a.k.a.

number of \"bad\" lines in each L2 file).

\- Metadata Name: OrbitNumber

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 1

Maximum Value: 999999

Data Source: L2

Description: The OMI orbit number for each L2 input granule.

\- Metadata Name: OrbitPeriod

Mandatory: T

Data Type: HE5T_NATIVE_DOUBLE

Number of Values: 1,16

Minimum Value: 5000.0

Maximum Value: 7000.0

Data Source: PGE

Description: The Aura orbital period for each L2 input granule.

\- Metadata Name: Period

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: Daily,Weekly,Monthly

Data Source: PGE

Description: The duration of the L2G granule. Actual is \"Daily\".

\- Metadata Name: PGEVERSION

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: PCF

Description: Example is \"1.0.0\" (see Appendix K of Reference 4).

\- Metadata Name: ProcessLevel

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: 2G

Data Source: PGE

Description: Actual is \"2G\".

\- Metadata Name: QAPercentCloudCover

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 0

Maximum Value: 100

Data Source: L2

Description: \>

The percent of data that have cloud cover in each L2 input granule.

\- Metadata Name: QAPercentMissingData

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 0

Maximum Value: 100

Data Source: L2

Description: \>

The percent of Level 1B calibrated radiance data that is missing from
each

L2 input granule.

\- Metadata Name: QAPercentOutOfBoundsData

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1,16

Minimum Value: 0

Maximum Value: 100

Data Source: L2

Description: \>

The percent of data that are out of bounds in each L2 input granule.

\- Metadata Name: StartUTC

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: PGE

Description: \>

UTC at the start of the L2G granule in \"YYYY-MM-DDT00:00:00.000000Z\"
format.

\- Metadata Name: TAI93At0zOfGranule

Mandatory: T

Data Type: HE5T_NATIVE_DOUBLE

Number of Values: 1

Minimum Value: 0.0

Maximum Value: 1.0e+30

Data Source: PGE

Description: \>

The TAI93 time at 0z of the L2G granule (see Section 6.1 of Reference
3).

Grid Metadata:

\- Metadata Name: GCTPProjectionCode

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 99

Data Source: PGE

Description: \>

The GCTP projection code of the L2G grid. Actual is 0, which corresponds

to the geographic projection.

\- Metadata Name: GridName

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: Aerosol NearUV Swath

Data Source: PGE

Description: Actual is \"Aerosol NearUV Swath\".

\- Metadata Name: GridOrigin

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: Center

Data Source: PGE

Description: \>

The location of longitude and latitude quoted for each L2G grid cell.

Actual is, on average, \"Center\" (see Section 6.2 of Reference 3).

\- Metadata Name: GridSpacing

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: PGE

Description: \>

Spacing of L2G grid (in degrees). Actual is \"(0.25,0.25)\".

\- Metadata Name: GridSpacingUnit

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: deg

Data Source: PGE

Description: \>

Unit for GridSpacing. Actual is \"deg\".

\- Metadata Name: GridSpan

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Data Source: PGE

Description: \>

Span of L2G grid (in degrees). Actual is \"(-180,180,-90,90)\".

\- Metadata Name: GridSpanUnit

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: deg

Data Source: PGE

Description: \>

Unit for GridSpan. Actual is \"deg\".

\- Metadata Name: MaximumNumberOfCandidatesPerGridCell

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 15

Data Source: PGE

Description: \>

The maximum number of L2 scenes per cell in the L2G grid (this can be as

large as 12).

\- Metadata Name: MinimumNumberOfCandidatesPerGridCell

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 15

Data Source: PGE

Description: \>

The minimum number of L2 scenes per cell in the L2G grid (this is
typically

0, because empty L2G grid cells are quite common).

\- Metadata Name: NumberOfEmptyGridCells

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1036800

Data Source: PGE

Description: \>

The number of cells in the L2G grid that do not contain any L2 scenes.

\- Metadata Name: NumberOfDuplicateScenesAcceptedIntoGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1500000

Data Source: PGE

Description: \>

The number of L2 scenes accepted into L2G grid cells that already
contain

one or more L2 scenes.

\- Metadata Name: NumberOfGridCells

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 1036800

Data Source: PGE

Description: The total number of cells in the L2G grid.

\- Metadata Name: NumberOfLatitudesInGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 720

Data Source: PGE

Description: The number of latitude bins in the L2G grid.

\- Metadata Name: NumberOfLongitudesInGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 1

Maximum Value: 1440

Data Source: PGE

Description: The number of longitude bins in the L2G grid.

\- Metadata Name: NumberOfMultiplyPopulatedGridCells

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1036800

Data Source: PGE

Description: \>

The number of cells in the L2G grid that contain two or more L2 scenes.

\- Metadata Name: NumberOfPopulatedGridCells

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1036800

Data Source: PGE

Description: \>

The number of cells in the L2G grid that contain one or more L2 scenes.

\- Metadata Name: NumberOfScenesAcceptedIntoGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1500000

Data Source: PGE

Description: The number of L2 scenes accepted into the L2G grid.

\- Metadata Name: NumberOfScenesConsideredForGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1500000

Data Source: PGE

Description: The number of L2 scenes considered for the L2G grid.

\- Metadata Name: NumberOfScenesRejectedFromGrid

Mandatory: T

Data Type: HE5T_NATIVE_INT

Number of Values: 1

Minimum Value: 0

Maximum Value: 1500000

Data Source: PGE

Description: The number of L2 scenes rejected from the L2G grid.

\- Metadata Name: Projection

Mandatory: T

Data Type: HE5T_NATIVE_CHAR

Number of Values: 1

Valids: Geographic

Data Source: PGE

Description: \>

The map projection of the L2G grid. Actual is \"Geographic\" (see

Section 6.2 of Reference 3).

Grid Dimensions:

\- Dimension Name: nCandidate

Data Type: HE5T_NATIVE_INT

Dimension Type: FIXED

Number of Values: 1

Minimum Value: 1

Maximum Value: 15

Data Source: PGE

Description: \>

The L2-candidate-scenes dimension of the L2G grid. The size of this

dimension is currently set at 15.

\- Dimension Name: nWavel

Data Type: HE5T_NATIVE_INT

Dimension Type: FIXED

Number of Values: 1

Minimum Value: 1

Maximum Value: 3

Data Source: PGE

Description: \>

The wavelengths dimension of the L2G grid. There are currently three

wavelengths in both OMAERUV and OMAERUVG.

\- Dimension Name: XDim

Data Type: HE5T_NATIVE_INT

Dimension Type: FIXED

Number of Values: 1

Minimum Value: 1

Maximum Value: 1440

Data Source: PGE

Description: \>

The longitudes dimension of the L2G grid. There are currently 1440

0.25-degree-wide bins between longitudes -180.0 and 180.0 degrees.

\- Dimension Name: YDim

Data Type: HE5T_NATIVE_INT

Dimension Type: FIXED

Number of Values: 1

Minimum Value: 1

Maximum Value: 720

Data Source: PGE

Description: \>

The latitudes dimension of the L2G grid. There are currently 720

0.25-degree-wide bins between latitudes -90.0 and 90.0 degrees.

Geolocation Fields:

\- Field Name: GroundPixelQualityFlags

Data Type: HE5T_NATIVE_UINT16

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0

Maximum Value: 65534

Missing Value: 65535

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Ground Pixel Quality Flags

Unique Field Definition: OMI-Specific

Description: \>

The ground pixel quality flags for each L2 candidate scene in each L2G
grid

cell:

Bits 0 to 3 together contain the land/water flags:

0 - shallow ocean

1 - land

2 - shallow inland water

3 - ocean coastline/lake shoreline

4 - ephemeral (intermittent) water

5 - deep inland water

6 - continental shelf ocean

7 - deep ocean

8-14 - not used

15 - error flag for land/water

Bits 4 to 6 are flags that are set to 0 for FALSE, or 1 for TRUE:

Bit 4 - sun glint possibility flag

Bit 5 - solar eclipse possibility flag

Bit 6 - geolocation error flag

Bit 7 is reserved for future use (currently set to 0).

Bits 8 to 14 together contain the snow/ice flags (based on NISE):

0 - snow-free land

1-100 - sea ice concentration (percent)

101 - permanent ice (Greenland, Antarctica)

102 - not used

103 - dry snow

104 - ocean (NISE-255)

105-123 - reserved for future use

124 - mixed pixels at coastline (NISE-252)

125 - suspect ice value (NISE-253)

126 - corners undefined (NISE-254)

127 - error

Bit 15 - NISE nearest neighbor filling flag.

(See Section 6.2 of Reference 5 for more details.)

\- Field Name: Latitude

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: -90.0

Maximum Value: 90.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: deg

Data Source: L2

Title: Geodetic Latitude (deg)

Unique Field Definition: Aura-Shared

Description: \>

The geodetic latitude (in degrees) on the ground at the center of each
L2

candidate scene in each L2G grid cell.

\- Field Name: LineNumber

Data Type: HE5T_NATIVE_INT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 1

Maximum Value: 1700

Missing Value: -2000000000

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Line Number of Candidate Scene

Unique Field Definition: OMI-Specific

Description: \>

The line number for each L2 candidate scene in each L2G grid cell.

\- Field Name: Longitude

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: -180.0

Maximum Value: 180.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: deg

Data Source: L2

Title: Geodetic Longitude (deg)

Unique Field Definition: Aura-Shared

Description: \>

The geodetic longitude (in degrees) on the ground at the center of each
L2

candidate scene in each L2G grid cell.

\- Field Name: NumberOfCandidateScenes

Data Type: HE5T_NATIVE_INT

Dimensions: YDim,XDim

Minimum Value: 0

Maximum Value: 100

Missing Value: 0

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: PGE

Title: Number of Candidate Scenes

Unique Field Definition: OMI-Specific

Description: \>

The number of L2 candidate scenes in each L2G grid cell.

\- Field Name: OrbitNumber

Data Type: HE5T_NATIVE_INT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 1

Maximum Value: 999999

Missing Value: -2000000000

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Orbit Number of Candidate Scene

Unique Field Definition: OMI-Specific

Description: \>

The orbit number for each L2 candidate scene in each L2G grid cell.

\- Field Name: PathLength

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 2.0

Maximum Value: 100.0

Missing Value: 1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: PGE

Title: Path Length

Unique Field Definition: OMI-Specific

Description: \>

The path length \[= sec(solar zenith angle) + sec(viewing zenith
angle)\] for

each L2 candidate scene in each L2G grid cell.

\- Field Name: ScatteringAngle

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 180.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: deg

Data Source: L2

Title: Scattering Angle

Unique Field Definition: OMI-Specific

Description: \>

The scattering angle

\[= acos(cos(solar zenith angle) \* cos(viewing zenith angle)

\+ sin(solar zenith angle) \* sin(viewing zenith angle)

\* cos(relative azimuth angle))\]

(in degrees) on the ground at the center of each L2 candidate scene in
each

L2G grid cell. Also known as glint angle.

\- Field Name: SceneNumber

Data Type: HE5T_NATIVE_INT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 1

Maximum Value: 60

Missing Value: -2000000000

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Scene Number of Candidate Scene

Unique Field Definition: OMI-Specific

Description: \>

The cross-track ground-pixel number for each L2 candidate scene in each
L2G

grid cell.

\- Field Name: SecondsInDay

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 86401.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: s

Data Source: L2

Title: Seconds in Day at Start of Scan

Unique Field Definition: Aura-Shared

Description: \>

The time after UTC midnight (in seconds) for each L2 candidate scene in
each

L2G grid cell.

\- Field Name: SolarZenithAngle

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 180.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: deg

Data Source: L2

Title: Solar Zenith Angle (deg)

Unique Field Definition: Aura-Shared

Description: \>

The solar zenith angle (in degrees) on the ground at the center of each
L2

candidate scene in each L2G grid cell.

\- Field Name: TerrainPressure

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 1013.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: torr

Data Source: L2

Title: Terrain Pressure (torr)

Unique Field Definition: Aura-Shared

Description: \>

The terrain pressure (in torr) at the center of each L2 candidate scene
in

each L2G grid cell.

\- Field Name: Time

Data Type: HE5T_NATIVE_DOUBLE

Dimensions: nCandidate,YDim,XDim

Minimum Value: -5.0e+09

Maximum Value: 1.0e+10

Missing Value: -1.2676506002282294e+30

Offset: 0.0

Scale Factor: 1.0

Units: s

Data Source: L2

Title: Time at Start of Scan

Unique Field Definition: Aura-Shared

Description: \>

The TAI93 time (in seconds) for each L2 candidate scene in each L2G grid

cell.

\- Field Name: ViewingZenithAngle

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 180.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: deg

Data Source: L2

Title: Viewing Zenith Angle (deg)

Unique Field Definition: OMI-Specific

Description: \>

The viewing zenith angle (in degrees) on the ground at the center of
each L2

candidate scene in each L2G grid cell.

Data Fields:

\- Field Name: AerosolLayerHeight

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0.0

Maximum Value: 10.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: km

Data Source: L2

Title: Aerosol Layer Height (km)

Unique Field Definition: OMI-Specific

Description: \>

The aerosol layer height (in km) for each L2 candidate scene in each L2G

grid cell.

\- Field Name: AerosolType

Data Type: HE5T_NATIVE_UINT8

Dimensions: nCandidate,YDim,XDim

Minimum Value: 1

Maximum Value: 255

Missing Value: 255

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Aerosol Type

Unique Field Definition: OMI-Specific

Description: \>

The aerosol type for each L2 candidate scene in each L2G grid cell:

1 - Smoke

2 - Dust

3 - Industrial

255 - Unknown

\- Field Name: AlgorithmFlags

Data Type: HE5T_NATIVE_UINT16

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0

Maximum Value: 65534

Missing Value: 65535

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Algorithm Flags

Unique Field Definition: OMI-Specific

Description: \>

The algorithm flags for each L2 candidate scene in each L2G grid cell:

Bit 0 - Reflectivity threshold limit 15%

Bit 1 - Single Scattering Albedo extrapolated

Bit 2 - Optical Depth extrapolated

Bit 3 - Invalid Aerosol Type calculation

Bit 4 - High probability of SunGlint

Bit 5 - OpticalDepth out-of-bounds

Bit 6 - High probability of Snow/Ice cover (SZA \< 80 degrees)

Bit 7 - SingleScatteringAlbedo out-of-bounds

Bit 8 - Unassigned

Bit 9 - TerrainPressure below threshold

Bit 10 - CloudContamination: 10-20%

Bit 11 - CloudContamination: 20-50%

(Both 10 & 11 , over 50%)

Bit 12 - SnowIceContamination up to 20%

Bit 13 - SnowIceContamination 20-50%

(Both 12 & 13 , over 50%)

Bit 14 - OceanColorContamination up to 20%

Bit 15 - OceanColorContamination 20-80%

(Both 14 & 15 , over 80%)

\- Field Name: FinalAerosoAbsOpticalDepth

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,nWavel,YDim,XDim

Minimum Value: 0.0

Maximum Value: 0.5

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Best Aerosol Absorption Optical Depth (tau_abs)

Unique Field Definition: OMI-Specific

Description: \>

The best aerosol absorption optical depth (tau_abs) solution for each L2

candidate scene in each L2G grid cell.

\- Field Name: FinalAerosolOpticalDepth

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,nWavel,YDim,XDim

Minimum Value: 0.0

Maximum Value: 4.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Best Aerosol Optical Depth (tau)

Unique Field Definition: OMI-Specific

Description: \>

The best aerosol optical depth (tau) solution for each L2 candidate
scene

in each L2G grid cell.

\- Field Name: MeasurementQualityFlags

Data Type: HE5T_NATIVE_UINT16

Dimensions: nCandidate,YDim,XDim

Minimum Value: 0

Maximum Value: 65534

Missing Value: 65535

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Measurement Quality Flags

Unique Field Definition: OMI-Specific

Description: \>

The measurement quality flags for each L2 candidate scene in each L2G
grid

cell:

Bit 0 - Test Mode

Bit 1 - Alternative Engineering Data

Bit 2 - Alternating Sequencing Readout

Bit 3 - Co-adder Error

Bit 4 - Invalid Co-addition Period

Bit 5 - Co-addition Possibility

Bit 6 - Measurement Combination

Bit 7 - Rebinning

Bit 8 - Dark Current Correction Processing Option

Bit 9 - Detector Smear Calculation Procesing Option

Bit 10 - SAA Possibility

Bit 11 - Spacecraft Maneuver

Bit 12 - Geolocation Error

Bit 13 - Reserved

Bit 14 - Reserved

Bit 15 - Reserved

\- Field Name: NormRadiance

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,nWavel,YDim,XDim

Minimum Value: 0.0

Maximum Value: 1.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Normalized Radiance

Unique Field Definition: OMI-Specific

Description: \>

The normalized radiance for each L2 candidate scene in each L2G grid
cell.

\- Field Name: Reflectivity

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,nWavel,YDim,XDim

Minimum Value: 0.0

Maximum Value: 1.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Lambert Equivalent Reflectivity

Unique Field Definition: OMI-Specific

Description: \>

The Lambert equivalent reflectivity for each L2 candidate scene in each
L2G

grid cell.

\- Field Name: SurfaceAlbedo

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,nWavel,YDim,XDim

Minimum Value: 0.0

Maximum Value: 1.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: Surface Albedo

Unique Field Definition: OMI-Specific

Description: \>

The surface albedo for each L2 candidate scene in each L2G grid cell.

\- Field Name: UVAerosolIndex

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: -10.0

Maximum Value: 30.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: UV Aerosol Index

Unique Field Definition: OMI-Specific

Description: \>

The UV aerosol index for each L2 candidate scene in each L2G grid cell.

\- Field Name: VISAerosolIndex

Data Type: HE5T_NATIVE_FLOAT

Dimensions: nCandidate,YDim,XDim

Minimum Value: -10.0

Maximum Value: 30.0

Missing Value: -1.2676506e+30

Offset: 0.0

Scale Factor: 1.0

Units: NoUnits

Data Source: L2

Title: VIS Aerosol Index

Unique Field Definition: OMI-Specific

Description: \>

The VIS aerosol index for each L2 candidate scene in each L2G grid cell.

Core Metadata:

\- Metadata Name: AssociatedInstrumentShortName

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: OMI

Data Source: MCF

Description: Actual is \"OMI\".

\- Metadata Name: AssociatedPlatformShortName

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: Aura

Data Source: MCF

Description: Actual is \"Aura\".

\- Metadata Name: AssociatedSensorShortName

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: CCD Ultra Violet,CCD Visible

Data Source: MCF

Description: Actual is \"CCD Visible\".

\- Metadata Name: AutomaticQualityFlag

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: Passed,Suspect,Failed

Data Source: PGE

Description: Actual is \"Failed\".

\- Metadata Name: AutomaticQualityFlagExplanation

Mandatory: T

Data Type: VA255

Number of Values: 1

Data Source: PGE

Description: \>

Actual is \"An automatic quality investigation has not yet been
devised.\"

\- Metadata Name: DayNightFlag

Mandatory: T

Data Type: VA5

Number of Values: 1

Valids: Day,Night,Both

Data Source: MCF

Description: Actual is \"Day\".

\- Metadata Name: EastBoundingCoordinate

Mandatory: T

Data Type: LF

Number of Values: 1

Minimum Value: -180.0

Maximum Value: 180.0

Data Source: PGE

Description: \>

The terrestrial longitude (in degrees) of the easternmost data in the
L2G

granule, which is typically 180.0 degrees.

\- Metadata Name: EquatorCrossingDate

Mandatory: T

Data Type: D

Number of Values: 1,16

Data Source: L2

Description: \>

The date of the ascending equator crossing for each L2 input granule.

\- Metadata Name: EquatorCrossingLongitude

Mandatory: T

Data Type: LF

Number of Values: 1,16

Minimum Value: -180.0

Maximum Value: 180.0

Data Source: L2

Description: \>

The terrestrial longitude (in degrees) of the ascending equator crossing
for

each L2 input granule.

\- Metadata Name: EquatorCrossingTime

Mandatory: T

Data Type: T

Number of Values: 1,16

Data Source: L2

Description: \>

The time of the ascending equator crossing for each L2 input granule.

\- Metadata Name: InputPointer

Mandatory: T

Data Type: VA255

Number of Values: 1,16

Data Source: PCF

Description: \>

A list of the L2 input granules. Example is

(\"OMI-Aura_L2-OMAERUV_2006m0101t0127-o07788_v002-2006m0630t195047.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t0306-o07789_v002-2006m0630t194941.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t0445-o07790_v002-2006m0630t194912.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t0624-o07791_v002-2006m0630t195527.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t0803-o07792_v002-2006m0630t195857.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t0942-o07793_v002-2006m0630t195945.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1121-o07794_v002-2006m0630t200413.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1300-o07795_v002-2006m0630t195904.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1438-o07796_v002-2006m0630t195021.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1617-o07797_v002-2006m0630t195347.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1756-o07798_v002-2006m0630t195454.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t1935-o07799_v002-2006m0630t195418.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t2114-o07800_v002-2006m0630t195155.he5\",

\"OMI-Aura_L2-OMAERUV_2006m0101t2253-o07801_v002-2006m0630t195327.he5\")

\- Metadata Name: LocalGranuleID

Mandatory: T

Data Type: VA80

Number of Values: 1

Data Source: PGE

Description: \>

Example is \"OMI-Aura_L2G-OMAERUVG_2006m0106_v002-2006m0317t220314.he5\"

(see Appendix E of Reference 4).

\- Metadata Name: LocalityValue

Mandatory: T

Data Type: VA20

Number of Values: 1

Data Source: MCF

Description: Actual is \"Global\".

\- Metadata Name: LOCALVERSIONID

Mandatory: T

Data Type: VA60

Number of Values: 1

Data Source: PCF

Description: \>

MD5 fingerprint of the HDF product file. Example valids are

\"RFC1321 MD5 = not yet calculated\" and \"RFC1321 MD5 =
\[0-9,a-f\]{32}\".

\- Metadata Name: NorthBoundingCoordinate

Mandatory: T

Data Type: LF

Number of Values: 1

Minimum Value: -90.0

Maximum Value: 90.0

Data Source: PGE

Description: \>

The terrestrial latitude (in degrees) of the northernmost data in the
L2G

granule, which typically lies in the range from 65.0 to 90.0 degrees.

\- Metadata Name: OperationalQualityFlag

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: \>

Passed,Failed,Being Investigated,Not Investigated,Inferred Passed,

Inferred Failed,Suspect

Data Source: PGE

Description: \>

Actual is \"Passed\".

\- Metadata Name: OperationalQualityFlagExplanation

Mandatory: T

Data Type: VA255

Number of Values: 1

Data Source: PGE

Description: \>

Actual is \"This granule passed operational tests that were administered

by the OMI SIPS. QA metadata was extracted and the file was successfully

read using standard HDF-EOS utilities.\".

\- Metadata Name: OrbitNumber

Mandatory: T

Data Type: I

Number of Values: 1,16

Minimum Value: 1

Maximum Value: 999999

Data Source: L2

Description: The OMI orbit number for each L2 input granule.

\- Metadata Name: ParameterName

Mandatory: T

Data Type: VA40

Number of Values: 1

Valids: OMAERUV

Data Source: PGE

Description: \>

The measured science parameter expressed in the L2G granule. Actual is

\"OMAERUV\".

\- Metadata Name: PGEVERSION

Mandatory: T

Data Type: VA10

Number of Values: 1

Data Source: PCF

Description: Example is \"1.0.0\" (see Appendix K of Reference 4).

\- Metadata Name: ProductionDateTime

Mandatory: T

Data Type: DT

Number of Values: 1

Data Source: TK

Description: The date and time of the Level 2G processing.

\- Metadata Name: QAPercentOutOfBoundsData

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 100

Data Source: PGE

Description: \>

An average for the entire L2G granule of the percent of data that are
out

of bounds.

\- Metadata Name: QAPercentMissingData

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 100

Data Source: PGE

Description: \>

An average for the entire L2G granule of the percent of missing Level 1B

calibrated radiance data.

\- Metadata Name: QAPercentCloudCover

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 100

Data Source: PGE

Description: \>

An average for the entire L2G granule of the percent of data that have

cloud cover.

\- Metadata Name: RangeBeginningDate

Mandatory: T

Data Type: D

Number of Values: 1

Data Source: PGE

Description: The year, month and day when the L2G granule begins.

\- Metadata Name: RangeBeginningTime

Mandatory: T

Data Type: T

Number of Values: 1

Data Source: PGE

Description: \>

The hour, minute, second and fraction of a second when the L2G granule

begins.

\- Metadata Name: RangeEndingDate

Mandatory: T

Data Type: D

Number of Values: 1

Data Source: PGE

Description: The year, month and day when the L2G granule ends.

\- Metadata Name: RangeEndingTime

Mandatory: T

Data Type: T

Number of Values: 1

Data Source: PGE

Description: \>

The hour, minute, second and fraction of a second when the L2G granule
ends.

\- Metadata Name: REPROCESSINGACTUAL

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: \>

processed 1 time,processed 2 times,processed 3 times,processed 4 times

Data Source: PCF

Description: \>

An indication of what reprocessing has been performed on the L2G
granule.

\- Metadata Name: ReprocessingPlanned

Mandatory: T

Data Type: VA40

Number of Values: 1

Valids: \>

no further update anticipated,further update is anticipated,

further update anticipated using enhanced PGE

Data Source: DP

Description: Actual is \"further update is anticipated\".

\- Metadata Name: ScienceQualityFlag

Mandatory: T

Data Type: VA20

Number of Values: 1

Valids: \>

Passed,Failed,Being Investigated,Not Investigated,Inferred Passed,

Inferred Failed,Suspect

Data Source: DP

Description: Actual is \"Not Investigated\".

\- Metadata Name: ScienceQualityFlagExplanation

Mandatory: T

Data Type: VA255

Number of Values: 1

Data Source: DP

Description: \>

Actual is \"An updated science quality flag and explanation is put in
the

product .met file when a granule has been evaluated. The flag value in

this file, Not Investigated, is an automatic default that is put into

every granule during production.\".

\- Metadata Name: ShortName

Mandatory: T

Data Type: VA8

Number of Values: 1

Valids: OMAERUVG

Data Source: MCF

Description: Actual is \"OMAERUVG\".

\- Metadata Name: SizeMBECSDataGranule

Mandatory: F

Data Type: LF

Number of Values: 1

Minimum Value: 0.0

Maximum Value: 10000.0

Data Source: DSS

Description: \>

The volume of data (in MB) contained in the L2G granule (this Metadata
will

not appear in the L2G granule).

\- Metadata Name: SouthBoundingCoordinate

Mandatory: T

Data Type: LF

Number of Values: 1

Minimum Value: -90.0

Maximum Value: 90.0

Data Source: PGE

Description: \>

The terrestrial latitude (in degrees) of the southernmost data in the
L2G

granule, which typically lies in the range from -90.0 to -65.0 degrees.

\- Metadata Name: VERSIONID

Mandatory: T

Data Type: SI

Number of Values: 1

Minimum Value: 0

Maximum Value: 999

Data Source: PCF

Description: Example is 2.

\- Metadata Name: WestBoundingCoordinate

Mandatory: T

Data Type: LF

Number of Values: 1

Minimum Value: -180.0

Maximum Value: 180.0

Data Source: PGE

Description: \>

The terrestrial longitude (in degrees) of the westernmost data in the
L2G

granule, which is typically -180.0 degrees.

Product Specific Attributes:

\- Metadata Name: ExpeditedData

Mandatory: T

Data Type: VA10

Number of Values: 1

Valids: TRUE,FALSE

Data Source: PGE

Description: The indicator for expedited Level 0 data.

\- Metadata Name: ExposureTimes

Mandatory: T

Data Type: F

Number of Values: 1,256

Minimum Value: 0.0

Maximum Value: 2000.0

Data Source: PGE

Description: \>

An array containing the exposure times (in seconds) used for the

measurements.

\- Metadata Name: MasterClockPeriods

Mandatory: T

Data Type: F

Number of Values: 1,128

Minimum Value: 0.0

Maximum Value: 10.0

Data Source: PGE

Description: \>

An array containing the master clock periods (in seconds) used for the

measurements.

\- Metadata Name: NrMeasurements

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 30000

Data Source: PGE

Description: \>

The number of measurements used to create the L2G granule.

\- Metadata Name: NrSpatialZoom

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 0

Data Source: PGE

Description: \>

The number of measurements in spatial zoom mode. Actual is 0, because

zoom measurements are excluded from the L2G granule.

\- Metadata Name: NrSpectralZoom

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 0

Data Source: PGE

Description: \>

The number of measurements in spectral zoom mode. Actual is 0, because

zoom measurements are excluded from the L2G granule.

\- Metadata Name: NrZoom

Mandatory: T

Data Type: I

Number of Values: 1

Minimum Value: 0

Maximum Value: 0

Data Source: PGE

Description: \>

The number of measurements in zoom modes. Actual is 0, because zoom

measurements are excluded from the L2G granule.

\- Metadata Name: SolarEclipse

Mandatory: T

Data Type: VA10

Number of Values: 1

Valids: TRUE,FALSE

Data Source: PGE

Description: \>

The indicator that during part of the measurements a solar eclipse
occurred.

\- Metadata Name: SouthAtlanticAnomalyCrossing

Mandatory: T

Data Type: VA10

Number of Values: 1

Valids: TRUE,FALSE

Data Source: PGE

Description: \>

The indicator that during part of the measurements the spacecraft was

in the South Atlantic Anomaly.

\- Metadata Name: SpacecraftManeuverFlag

Mandatory: T

Data Type: VA10

Number of Values: 1

Valids: TRUE,FALSE,UNKNOWN

Data Source: PGE

Description: \>

The indicator that during part of the measurements the spacecraft was

performing a maneuver.

Archived Metadata:

\- Metadata Name: ESDTDescriptorRevision

Mandatory: T

Data Type: VA10

Number of Values: 1

Data Source: MCF

Description: \>

The version of the ESDT descriptor file as determined by ECS.

\- Metadata Name: LongName

Mandatory: T

Data Type: VA80

Number of Values: 1

Valids: \>

OMI/Aura Aerosol Opt Depth & Sing Scatt Alb Daily L2 Global 0.25deg
Lat/Lon Grid

Data Source: MCF

Description: \>

Actual is

\"OMI/Aura Aerosol Opt Depth & Sing Scatt Alb Daily L2 Global 0.25deg
Lat/Lon Grid\".

References: \>

1\. \"OMI Algorithm Theoretical Basis, Volume III, Clouds, Aerosols, and
Surface UV Irradiance\"

(OMI-ATBD-VOL3, ATBD-OMI-03, Version 2.0, August 2002)

2\. \"Definition of OMI Grids for Level 3 and Level 4 Data Products\"

(OMI-Grids_L3L4, SD-OMIE-KNMI-443, 25 January 2005)

3\. \"HDF-EOS Aura File Format Guidelines\"

(OMI-AURA-DATA-GUIDE, Version 2.12, 24 October 2006)

4\. \"OMI Science Software Delivery Guide for Version 0.9\"

(OMI-SSDG-0.9.10, Version 0.9.10, 22 June 2005)

5\. \"OMI GDPS Input/Output Data Specification (IODS) Volume 2\"

(OMI-GDPS-IODS-2, SD-OMIE-7200-DS-467, 8 November 2004)

6\. \"OMAERUVG ECS Metadata Requirements\"

(OMI-OMAERUVG_Metadata_RD, Version 0.9.30, In Preparation)

7\. \"Release 6A Implementation Earth Science Data Model for the ECS
Project\"

(420-TP-022-002, June 2001)

(http://edhs1.gsfc.nasa.gov/waisdata/rel6/html/tp4202202.html and

http://edhs1.gsfc.nasa.gov/waisdata/rel6/html/tp42022_adds.html)