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GOES Space Environment Monitor (SEM) L1B & L2 data from NCEI, Version 1.0

Metadata Updated: December 16, 2023

*Note: This data has been reprocessed by NCEI adding quality flags and using consistent file formats across the period of record (POR). It is highly recommended that users access this version of the data. The Space Environment Monitor (SEM) is a suite of instruments onboard the GOES satellite series. The objective of the SEM package is to measure solar radiation in the X-ray and Extreme Ultraviolet (EUV) region, the in-situ magnetic field, and the energetic particle environment at geosynchronous orbit. This collection (v1) contains L1B and L2 data from GOES 1-15 and SMS 1-2. The SEM suite on SMS 1-2 and GOES 1-5 is composed of three sensors: SEM/EPS (Energetic Particle Sensor), SEM/MAG (Magnetometer) , and SEM/XRS (X-Ray Sensor). The SEM/HEPAD (High Energy Proton and Alpha Particles Detector) began with GOES 7. The GOES 13-15 SEM suite added these 3 sensors: SEM/EUVS (Extreme Ultraviolet Sensor), SEM/MAGED (Magnetospheric Electron Detector), and SEM/MAGPD (Magnetospheric Proton Detector). On GOES 13-15, the historical EPS sensor was renamed EPEAD (Electron, Proton, and Alpha Detector) and the term EPS now refers to the suite of particle detectors (EPEAD, MAGED, MAGPD). Combined these sensors provide magnetic field, energetic particle, and solar x-ray and EUV data. The magnetometer (MAG) measures the magnitude and direction of the magnetic field. The energetic particle detectors (EPS, HEPAD, EPEAD, MAGED, MAGPD, and MAGED) measure a spectrum of electron, proton, and alpha-particle fluxes caused by solar activity and galactic cosmic rays. The solar x-ray sensor (XRS) measures solar X-ray fluxes for the wavelength bands of 0.05-.4 nm (short channel) and .1 to .8 nm (long channel). The extreme ultraviolet sensor (EUVS) measures the EUV in 5 bands (A-E) spanning wavelengths 5-127 nm. The temporal period of record (POR) for this collection extends from July 1974 to March 2020. The L1b products include full-resolution data (cadence varies by sensor/satellite) provided in daily files in netcdf and csv formats. The L2 products include monthly averages (1 minute or 5 minute cadence) provided in monthly files in netcdf and csv formats. The data were produced by NOAA’s National Centers for Environment Information (NCEI) and archived by NOAA's Comprehensive Large Array-Data Stewardship System (CLASS).

Access & Use Information

License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources


Metadata Date November 10, 2023
Metadata Created Date December 16, 2023
Metadata Updated Date December 16, 2023
Reference Date(s) 1974-07 (publication)
Frequency Of Update notPlanned

Metadata Source

Harvested from NGDC STP Space Weather

Graphic Preview

Image of NOAA GOES spacecraft

Additional Metadata

Resource Type Dataset
Metadata Date November 10, 2023
Metadata Created Date December 16, 2023
Metadata Updated Date December 16, 2023
Reference Date(s) 1974-07 (publication)
Responsible Party DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
Contact Email
Guid gov.noaa.ncei.swx:goes_sem-l1b-l2_ncei
Access Constraints Cite as: GOES Space Environment Monitor (SEM) L1B & L2 data from NCEI, Version 1.0. [indicate subset used]. NOAA National Centers for Environmental Information. [access date]., Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Coupled Resource
Frequency Of Update notPlanned
Graphic Preview Description Image of NOAA GOES spacecraft
Graphic Preview File
Graphic Preview Type JPG
Harvest Object Id 79204bce-44f9-43d2-a4c6-d051b9695b35
Harvest Source Id 720e273e-9143-4e92-8a4c-fe2bf3aacd0b
Harvest Source Title NGDC STP Space Weather
Lineage The data were produced by NOAA's National Centers for Envioronmental Information (NCEI).
Metadata Language eng; USA
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System Non geographic dataset
Spatial Harvester True
Temporal Extent Begin 1974-07
Temporal Extent End 2020-03

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