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Description

The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September 1997 until the end of mission in December 2010. SeaWiFS had 8 spectral bands from 412 to 865 nm. It collected global data at 4 km resolution, and local data (limited onboard storage and direct broadcast) at 1 km. The mission and sensor were optimized for ocean color measurements, with a local noon (descending) equator crossing time orbit, fore-and-aft tilt capability, full dynamic range, and low polarization sensitivity.

Version Description

Data format changed from HDF5 to netCDF4.

Product Summary

Platforms
OrbView-2
Instruments
SeaWiFS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
1997-09-04 to 2010-12-11
Data Partner
Ocean Biology Processing Group (OBPG) ,
Ocean Biology Distributed Active Archive Center (OB.DAAC), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/GCDC/OB.DAAC)
Concept ID
C3202004252-OB_CLOUD
Data State
COMPLETE
Number of Files/Granules
58128
Processing Level
1
Published
Updated
Science Keywords
Ocean Color

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

NASA Ocean Biology Processing Group. (2025). OrbView-2 SeaWiFS Level-1A Merged Local Area Coverage (MLAC) Data, version 2 [Data set]. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/ORBVIEW-2/SEAWIFS/L1A/MLAC/2 Date Accessed: 2026-01-24

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
att_ang Computed yaw, roll, pitch N/A float32 N/A -180 to 180 N/A
cal_offs Calibration system offsets N/A float32 N/A N/A N/A
clat Scan center-pixel latitude N/A float32 N/A -90 to 90 N/A
clon Scan center-pixel longitude N/A float32 N/A -180 to 180 N/A
counts Digital counts of calibration knees N/A float32 N/A 0 to 1023 N/A
csol_z Scan center-pixel solar zenith angle N/A float32 N/A 0 to 180 N/A
dark_rest Dark-restore pixel N/A int16 N/A N/A N/A
elat Scan end-pixel latitude N/A float32 N/A -90 to 90 N/A
elon Scan end-pixel longitude N/A float32 N/A -180 to 180 N/A
eng_qual Engineering data-out-of-range flags N/A uint8 N/A N/A N/A
gain Band gain settings N/A int16 N/A 0 to 3 N/A
inst_ana Instrument analog telemetry N/A float32 N/A N/A N/A
inst_dis Instrument discrete telemetry N/A uint8 N/A N/A N/A
inst_tlm SeaWiFS instrument telemetry N/A int16 N/A N/A N/A
l1a_data Level-1A data N/A int16 N/A 0 to 1023 N/A
l_vert Local vertical vector in ECEF frame N/A float32 N/A -1 to 1 N/A
mirror Mirror-side correction factors N/A float32 N/A N/A N/A
nflag Navigation flags N/A int32 N/A N/A N/A
orb_vec Orbit position vector at scan line time kilometers float32 N/A -7200 to 7200 N/A
rads Radiances of calibration knees N/A float32 N/A N/A N/A
scan_ell Scan-track ellipse coefficients N/A float32 N/A N/A N/A
scan_temp Detector temperature counts N/A int16 N/A 0 to 255 N/A
scan_time Scan-line time, milliseconds of day milliseconds int32 N/A 0 to 86399999 N/A
sc_ana Spacecraft analog telemetry N/A float32 N/A N/A N/A
sc_dis Spacecraft discrete telemetry N/A uint8 N/A N/A N/A
sc_id Spacecraft ID N/A int16 N/A N/A N/A
sc_soh Spacecraft state-of-health data N/A uint8 N/A N/A N/A
sc_ttag Spacecraft time tag N/A int16 N/A N/A N/A
sen_mat ECEF-to-sensor-frame matrix N/A float32 N/A -1 to 1 N/A
side Mirror side for scan line N/A int16 N/A 0 to 1 N/A
slat Scan start-pixel latitude N/A float32 N/A -90 to 90 N/A
slon Scan start-pixel longitude N/A float32 N/A -180 to 180 N/A
start_syn Start-synch pixel N/A int16 N/A N/A N/A
stop_syn Stop-synch pixel N/A int16 N/A N/A N/A
sun_ref Reference Sun vector in ECEF frame N/A float32 N/A -1 to 1 N/A
s_flags Scan-line quality flags N/A uint8 N/A N/A N/A
s_satp Number of saturated pixels per band N/A int16 N/A N/A N/A
s_zerop Number of zero pixels per band N/A int16 N/A N/A N/A
tdi Band time-delay and integration settings N/A int16 N/A 0 to 255 N/A
tilt Tilt angle for scan line N/A float32 N/A -20.10000038147 to 20.10000038147 N/A
tilt_flags Tilt indicators N/A int16 N/A -1 to 3 N/A
tilt_lats Latitudes of tilt-range scan line end points N/A float32 N/A -90 to 90 N/A
tilt_lons Longitudes of tilt-range scan line end points N/A float32 N/A -180 to 180 N/A
tilt_ranges Scan-line number ranges of scene tilt states N/A int16 N/A N/A N/A
time time seconds since 1970-1-1 float64 N/A N/A N/A
t_const Time-dependent correction constant terms N/A float64 N/A N/A N/A
t_linear Time-dependent correction linear coefficients N/A float64 N/A N/A N/A
t_quadratic Time-dependent correction quadratic coefficients N/A float64 N/A N/A N/A
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