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Description

This dataset contains concurrent airborne DopplerScatt radar retrievals of surface vector winds and ocean currents from the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE) during a pilot campaign conducted approximately 300 km offshore of San Francisco over two weeks in October 2021. S-MODE aims to understand how ocean dynamics acting on short spatial scales influence the vertical exchange of physical and biological variables in the ocean. DopplerScatt is a Ka-band (35.75 GHz) scatterometer with a swath width of 24 km that records Doppler measurements of the relative velocity between the platform and the surface. It is mounted on a B200 aircraft which flies daily surveys of the field domain during deployments, and data is used to give larger scale context, and also to compare with in-situ measurements of velocities and divergence. Level 2 data includes estimates of surface winds and currents. The V1 data have been cross-calibrated against SIO-DopVis leading to the 'dopvis_2021' current geophysical model function. It is expected that additional DopVis data will lead to a reprocessing of this data set and it should be regarded as provisional, to be refined after future S-MODE deployments. Data are available in netCDF format.

Product Summary

Platforms
B-200
Instruments
DOPPLER RADAR
Spatial Extent

N: 38.2 S: 36.3 E: -122.1 W: -126.2

Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2021-10-20 to 2021-11-05
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2110184925-POCLOUD
Data State
COMPLETE
Number of Files/Granules
11
Processing Level
2
Science Keywords
Surface Winds ,
SURFACE CURRENTS ,
Doppler Velocity

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

S-MODE. (2022). S-MODE DopplerScatt Level 2 Ocean Winds and Currents Version 1 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/SMODE-DSCT2 Date Accessed: 2025-12-14

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
azimuth_diversity_flag_all_lines flag for valid wind retrieval 1 int N/A 0 to 1 1
azimuth_diversity_flag_line flag for valid wind retrieval 1 int N/A 0 to 1 1
azimuth_diversity_flag_triplet flag for valid wind retrieval 1 int N/A 0 to 1 1
latitude Measurement center latitude degrees_north float N/A -90 to 90 1
line flight lines used to make line estimates 1 int N/A 0 to 100 1
longitude Measurement center longitude degrees_east float N/A -180 to 180 1
look_diff_all_lines best azimuthal angle difference among observations degrees float N/A -180 to 180 1
look_diff_line best azimuthal angle difference among observations degrees float N/A -180 to 180 1
look_diff_triplet best azimuthal angle difference among observations degrees float N/A -180 to 180 1
max_triplet_observation_time Triplet forward and backward measurement UTC time maximum. days since 1950-01-01T00:00:00Z float N/A 0 to 36500 1
mean_observation_time Forward and backward measurement UTC time average. days since 1950-01-01T00:00:00Z double N/A 0 to 36500 1
mean_triplet_observation_time Triplet forward and backward measurement UTC time average. days since 1950-01-01T00:00:00Z float N/A 0 to 36500 1
min_triplet_observation_time Triplet forward and backward measurement UTC time minimum. days since 1950-01-01T00:00:00Z float N/A 0 to 36500 1
nobs_all_lines Total number of observations. 1 int N/A 0 to 100 1
spatial_ref spatial_ref N/A int N/A N/A 1
triplet flight line triplets used to make triplet estimates 1 int N/A 0 to 100 1
u_current_all_lines Surface current east component m s-1 float N/A -5 to 5 1
u_current_error_all_lines Surface current east component standard deviation m s-1 float N/A 0 to 5 1
u_current_error_line Surface current north component standard deviation m s-1 float N/A 0 to 5 1
u_current_error_triplet Surface current east component standard deviation m s-1 float N/A 0 to 5 1
u_current_line Surface current east component m s-1 float N/A -5 to 5 1
u_current_triplet Surface current east component m s-1 float N/A -5 to 5 1
v_current_all_lines Surface current north component m s-1 float N/A -5 to 5 1
v_current_error_all_lines Surface current north component standard deviation m s-1 float N/A 0 to 5 1
v_current_error_triplet Surface current north component standard deviation m s-1 float N/A 0 to 5 1
v_current_line Surface current north component m s-1 float N/A -5 to 5 1
v_current_triplet Surface current north component m s-1 float N/A -5 to 5 1
winds_likely_corrupted_line wind estimation quality flag 1 int N/A 0 to 1 1
winds_likely_corrupted_triplet wind estimation quality flag 1 int N/A 0 to 1 1
wind_dir_all_lines Wind to direction clockwise relative to north. degrees float N/A -180 to 180 1
wind_dir_error_all_lines Wind to direction error clockwise relative to north. degrees float N/A -180 to 180 1
wind_dir_error_line Wind to direction error clockwise relative to north. degrees float N/A -180 to 180 1
wind_dir_error_triplet Wind to direction error clockwise relative to north. degrees float N/A -180 to 180 1
wind_dir_line Wind to direction clockwise relative to north. degrees float N/A -180 to 180 1
wind_dir_line_merged Neutral wind speed at 10m m s-1 float N/A 0 to 50 1
wind_dir_triplet Wind to direction clockwise relative to north. degrees float N/A -180 to 180 1
wind_speed_all_lines Neutral wind speed at 10m m s-1 float N/A 0 to 50 1
wind_speed_error_all_lines Neutral wind speed error at 10m m s-1 float N/A 0 to 50 1
wind_speed_error_line Neutral wind speed error at 10m m s-1 float N/A 0 to 50 1
wind_speed_error_triplet Neutral wind speed error at 10m m s-1 float N/A 0 to 50 1
wind_speed_line Neutral wind speed at 10m m s-1 float N/A 0 to 50 1
wind_speed_line_merged Neutral wind speed at 10m m s-1 float N/A 0 to 50 1
wind_speed_triplet Neutral wind speed at 10m m s-1 float N/A 0 to 50 1
x UTM easting m double N/A -1000000 to 1000000 1
xt_bias_u_line cross-track bias in wind v-component m s-1 float N/A -10 to 10 1
xt_bias_v_line cross-track bias in wind v-component m s-1 float N/A -10 to 10 1
y UTM northing m double N/A -1000000 to 10000000 1
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