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Description

The Spectro-polarimeter for Planetary Exploration one (SPEXone) instrument flying aboard the PACE spacecraft is a multi-angle polarimeter. It measures the intensity, Degree of Linear Polarization (DoLP) and Angle of Linear Polarization (AoLP) of sunlight reflected back from Earth's atmosphere, land surface, and ocean. The focus of the SPEXone development is to achieve a very high accuracy of DoLP measurements, which facilitates accurate characterization of aerosols in the atmosphere.

Version Description

Initial dataset

Product Summary

Platforms
PACE
Instruments
SPEXone
Spatial Extent

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

Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2024-02-23 to Present
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
C3285304315-OB_CLOUD
Data State
ACTIVE
Number of Files/Granules
8823
Processing Level
1
Published
Updated
Science Keywords
Ocean Color ,
Aerosol Particle Properties

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. (2024). PACE SPEXone Level-1B Science Data, version 3 [Data set]. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/PACE/SPEXONE/L1B/SCI/3 Date Accessed: 2025-12-13

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
BIN_ATTRIBUTES/image_time image time (seconds of day) seconds float64 -32767 0 to 172800 N/A
GEOLOCATION_DATA/height Height at bin locations m float32 -32767 -1000 to 10000 N/A
GEOLOCATION_DATA/latitude Latitudes of bin locations degrees_north float32 -32767 -90 to 90 N/A
GEOLOCATION_DATA/longitude Longitudes of bin locations degrees_east float32 -32767 -180 to 180 N/A
GEOLOCATION_DATA/sensor_azimuth Sensor azimuth angle degrees float32 -32767 -180 to 180 N/A
GEOLOCATION_DATA/sensor_zenith Sensor zenith angle degrees float32 -32767 -90 to 90 N/A
GEOLOCATION_DATA/solar_azimuth Solar azimuth angle at bin locations degrees float32 -32767 -180 to 180 N/A
GEOLOCATION_DATA/solar_zenith Solar zenith angle at bin locations degrees float32 -32767 -90 to 90 N/A
image_attributes/icu_time_sec ICU time stamp (seconds) seconds since 1958-01-01 00:00:00 TAI uint32 N/A 1956528000 to 2493072000 N/A
image_attributes/icu_time_subsec ICU time stamp (sub-seconds) 1/65536 s uint16 N/A 0 to 65535 N/A
navigation_data/att_quat Attitude quaternions (J2000 to spacecraft) seconds float32 -32767 -1 to 1 N/A
navigation_data/att_time Attitude sample time (seconds of day) seconds since 2025-01-15 float64 -32767 0 to 172800 N/A
navigation_data/orb_pos Orbit position vectors (ECR) meters float32 -9999999 -7200000 to 7200000 N/A
navigation_data/orb_time Orbit vector time (seconds of day) seconds since 2025-01-15 float64 -32767 0 to 172800 N/A
navigation_data/orb_vel Orbit velocity vectors (ECR) meters/second float32 -32767 -7600 to 7600 N/A
OBSERVATION_DATA/aolp Angle of linear polarization degrees float32 -32767 0 to 180 N/A
OBSERVATION_DATA/aolp_stdev Standard deviation of AOLP in bin degrees float32 -32767 0 to 18000 N/A
OBSERVATION_DATA/dolp Degree of linear polarization 1 float32 -32767 0 to 1 N/A
OBSERVATION_DATA/dolp_stdev Standard deviation of DOLP in bin 1 float32 -32767 0 to 20000 N/A
OBSERVATION_DATA/i I Stokes vector component W m^-2 sr^-1 um^-1 float32 -32767 0 to 999 N/A
OBSERVATION_DATA/i_polsample I Stokes vector component at polarimeter spectral sampling W m^-2 sr^-1 um^-1 float32 -32767 0 to 999 N/A
OBSERVATION_DATA/i_polsample_stdev standard deviation of i_polsample in bin W m^-2 sr^-1 um^-1 float32 -32767 0 to 800 N/A
OBSERVATION_DATA/i_stdev Standard deviation of I in bin W m^-2 sr^-1 um^-1 float32 -32767 0 to 800 N/A
OBSERVATION_DATA/qc Quality indicator 1 float32 -32767 0 to 10 N/A
OBSERVATION_DATA/q_over_i Q over I (little q) Stokes vector component 1 float32 -32767 -1.5 to 1.5 N/A
OBSERVATION_DATA/q_over_i_stdev Standard deviation of q_over_i in bin 1 float32 -32767 N/A N/A
OBSERVATION_DATA/u_over_i U over I (little u) Stokes vector component 1 float32 -32767 -1.5 to 1.5 N/A
OBSERVATION_DATA/u_over_i_stdev Standard deviation of u_over_i in bin 1 float32 -32767 N/A N/A
processor_configuration processor_configuration N/A OTHER N/A N/A N/A
SENSOR_VIEW_BANDS/intensity_bandpass Intensity field bandpass at each view nm float32 -32767 0 to 100 N/A
SENSOR_VIEW_BANDS/intensity_f0 Intensity band solar irradiance W m^-2 um^-1 float32 -32767 0 to 5000 N/A
SENSOR_VIEW_BANDS/intensity_wavelength Intensity field center wavelengths at each view nm float32 -32767 340 to 800 N/A
SENSOR_VIEW_BANDS/polarization_bandpass Polarization field bandpasses at each view nm float32 -32767 2.5 to 100 N/A
SENSOR_VIEW_BANDS/polarization_f0 Polarization band solar irradiance W m^-2 um^-1 float32 -32767 0 to 5000 N/A
SENSOR_VIEW_BANDS/polarization_wavelength Polarization field wavelengths at each view nm float32 -32767 340 to 800 N/A
SENSOR_VIEW_BANDS/viewport_index zero-based viewport index for each spatial sample N/A uint8 255 0 to 4 N/A
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