• Welcome to the new nsidc.org! To get acquainted with what's changed, read our spotlight article: NSIDC.org website: New look and new features.

    Please note that we are in a beta launch of this website. During the beta phase, our website search may act unpredictably until the website stabilizes.

SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures, Version 4 (SPL1BTB)
Data set:
SPL1BTB
Citation
There is a more recent version of these data.
Version Summary

Changes to this version include:




  • Added procedure to correct brightness temperatures for water/land contamination near coastlines. New data fields for this correction include:
    footprint_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_surface_corrected, and tb_v_surface_corrected.

  • Improved Level-1 calibration coefficients and reflected galaxy correction. To refine reflected galaxy correction over ocean, NOAA NCEP ocean roughness data have been added (wind_direction_ancillary, wind_speed_ancillary).




For the full major and minor version history, go to https://nsidc.org/data/smap/data_versions.

Overview

This Level-1B (L1B) product provides calibrated estimates of time-ordered geolocated brightness temperatures measured by the Soil Moisture Active Passive (SMAP) passive microwave radiometer. SMAP L-band brightness temperatures are referenced to the Earth's surface with undesired and erroneous radiometric sources removed.
Data Contributor(s):
Piepmeier, J. R., P. Mohammed, J. Peng, E. J. Kim, G. De Amici, J. Chaubell, and C. Ruf.
Parameter(s):
ANTENNA TEMPERATURE BRIGHTNESS TEMPERATURE
Platform(s):
SMAP
Sensor(s):
SMAP L-BAND RADIOMETER
Data Format(s):
HDF5
Temporal Coverage:
31 March 2015 to 27 August 2020
Temporal Resolution:
49 minute
Spatial Resolution:
36 km
47 km
Spatial Coverage:
N:
86.4
S:
-86.4
E:
180
W:
-180

Data Access & Tools

This data set has been retired. There is a more recent version of these data.

Help Articles

How To

Many NSIDC data set web pages provide the ability to search and filter data with spatial and temporal contstraints using a map-based interface. This article outlines how to order NSIDC DAAC data using advanced searching and filtering. 
To convert HDF5 files into binary format you will need to use the h5dump utility, which is part of the HDF5 distribution available from the HDF Group. How you install HDF5 depends on your operating system.
Data subscriptions are available for select NSIDC DAAC data collections (found below). Our subscription service automatically sends you new data as they are delivered from active NASA satellite missions.
  Data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system or through our Application Programming Interface (API).
NASA Worldview uses the Global Imagery Browse Service (GIBS) to provide up to date, full resolution imagery for select NSIDC DAAC data sets (see attachments below).
NASA's Global Imagery Browse Services (GIBS) provides up to date, full resolution imagery for selected NSIDC DAAC data sets. 

Getting started

SMAP Ancillary data sets are used to produce SMAP Level-1, -2, -3, and -4 standard data products.
The following table describes both the required and actual latencies for the different SMAP radiometer data sets. Latency is defined as the time (# days, hh:mm:ss) from data acquisition to product generation.