The Geostationary Operational Environmental Satellites (GOES) are a series of key satellites NOAA has used to monitor weather and space weather since 1975. GOES superseded the Synchronous Meteorological Satellite (SMS) series that was in operation from 1974–1978. These satellites carried multiple series of space-weather instruments for measuring particles, the magnetic field, solar irradiance, and solar image monitors.
Space Environment Monitor (SEM)
The Space Environment Monitor (SEM) instrument suite was a set of space weather instruments on the SMS and GOES 1–15 satellites. At various times, the instruments aboard these satellites included:
SEM Instruments
- Electron, Proton, and Alpha Detector (EPEAD)
- Energetic Particle Sensor (EPS)
- Extreme Ultraviolet Sensor (EUVS)
- High Energy Proton and Alpha Detector (HEPAD)
- Magnetometer (MAG)
- Magnetospheric Electron Detector (MAGED)
- Magnetospheric Proton Detector (MAGPD)
- Solar X-ray Imager (SXI) and X-ray Sensors (XRS)
These satellites have provided magnetometer, energetic particle, and soft X-ray data continuously since July 1974. The Solar X-ray Imager (SXI) was introduced on GOES-12 (2001). Extreme Ultraviolet Sensors (EUVS) were introduced on GOES-13 (2006), providing complementary solar irradiance measurements to the traditional GOES X-ray sensors (XRS). Data from the High Energy Proton and Alpha Detector (HEPAD) is available starting with GOES-6 (1983). The Magnetospheric Electron Detectors (MAGED) and Proton Detectors (MAGPD) were introduced on GOES-13, and the Energetic Particle Sensors (EPS) were renamed Energetic Proton, Electron and Alpha Detectors (EPEAD)
Geosynchronous satellites have an unobstructed view of the Sun for all but a few dozen hours per year when Earth eclipses the Sun. These intervals appear as gaps of up to 80 minutes in the irradiance and imaging data for about six weeks around the time of the equinoxes. Users are encouraged to read the available documentation, be wary of 'anomalies' in the data, and attempt to corroborate them with other sources before assuming they accurately represent the space environment. For questions about the data, use the contact info in the relevant readmes, or email ncei.info@noaa.gov.
| SMS/GOES Mission overview | ||||
|---|---|---|---|---|
| Satellite | Launch Date | First Data | Last Data | Available Data |
| SMS-1 overview | 1974-05-17 | 1974-07 | 1975-10 | EPS, MAG, XRS |
| SMS-2 overview | 1975-02-06 | 1975-02 | 1978-03 | EPS, MAG, XRS |
| GOES-1 overview | 1975-10-16 | 1976-01 | 1978-05 | EPS, MAG, XRS |
| GOES-2 overview | 1977-06-16 | 1977-08 | 1983-05 | EPS, MAG, XRS |
| GOES-3 overview | 1978-06-16 | 1978-07 | 1980-08 | EPS, XRS |
| GOES-4 overview | 1980-09-09 | system failure | n/a | none |
| GOES-5 overview | 1981-05-22 | 1983-01 | 1987-02 | EPS, XRS |
| GOES-6 overview | 1983-04-22 | 1983-05 | 1994-11 | EPS, HEPAD, XRS |
| GOES-7 overview | 1987-02026 | 1987-03 | 1996-08 | EPS, XRS |
| GOES-08 overview | 1994-04-13 | 1995-01 | 2003-06 | EPS, HEPAD, XRS |
| GOES-09 overview | 1995-05-23 | 1996-04 | 1998-07 | EPS, HEPAD, XRS |
| GOES-10 overview | 1997-04-25 | 1998-07 | 2009-12 | EPS, HEPAD, XRS |
| GOES-11 overview | 2000-05-03 | 2000-07 | 2011-02 | EPS, HEPAD, XRS |
| GOES-12 overview | 2001-07-23 | 2003-01 | 2010-08 | EPS, HEPAD, XRS |
| GOES-13 overview | 2006-05-24 | 2010-05 | 2017-12 | EUVS, XRS, EPEAD, HEPAD, MAGED, MAGPD |
| GOES-14 overview | 2009-06-27 | 2010-01 | 2020-03 | EUVS, XRS, EPEAD, HEPAD, MAGED, MAGPD |
| GOES-15 overview | 2010-03-04 | 2010-09 | 2020-03 | EUVS, XRS, EPEAD, HEPAD, MAGED, MAGPD |
NOAA geostationary satellites have made operational measurements of X-ray solar irradiance from SMS-1 since 1974 and extreme ultraviolet (EUV) irradiance from GOES-13 since 2006.
X-Ray Sensor (XRS)
XRS provides solar X-ray fluxes for the wavelength bands of 0.5 to 4 Å and 1 to 8 Å. Science-quality data is available for GOES 13–15, as described in GOES XRS Science-Quality Data Readme and the GOES -R XRS L2 Users Guide. To access observed fluxes from the operational data for the other satellites, refer to the scaling factor correction process described in the GOES XRS Operational Data Readme.
Extreme Ultraviolet Sensors (EUVS)
The GOES-13, 14, and 15 satellites used EUVS sensors to measure extreme ultraviolet irradiance. Transmission grating spectrographs measured five spectral bands between 5 and 127 nm. Calibrated data are available for the following primary channels, each of which have 1 minute and daily cadences:
- A (5-15 nm)
- B (25-35 nm)
- E (115-130 nm)
Science-quality solar line data are available through 2016 for the Lyman alpha (121.6 nm) and through 2014 for He II (30.4 nm). See the GOES EUVS Data Readme for information about the EUVS data or data access.
When available, we strongly recommend using science quality data in your study. These data have been reprocessed with updated calibrations.
Science Quality XRS Data
Note: Reprocessed science-quality XRS data will be available for GOES 8–12 (December 2022) and GOES-1-7 (Spring 2023).
| Product | Satellite Data | Description | Plots |
|---|---|---|---|
| 2-second Fluxes | High cadence XRS measurements | ||
| 1-min Averages | 1-minute averages of XRS measurements | 1-min. average plots | |
| Flare Summary | List of solar flares | ||
| Daily Background | Daily X-ray background | ||
| Ephemeris |
Science Quality EUVS Data
Note: Reprocessed science-quality EUVS data will be available for GOES-13–15 (2010–2020) for the following frequencies:
- 121.6 nm (December 2022)
- 30.4 nm (Spring 2023)
| Product | Description | Annual Plots |
|---|---|---|
| EUVS v2 (.txt) | EUVS-A and -B 1-min and daily irradiance averages (.txt) | EUVS v2 Plots |
| EUVS-E (Lyman alpha) 1-min and daily irradiance averages | EUVS v4 Plots | |
| AU Correction Factor | Daily multiplicative 1-AU correction factor for for 2006–2010 | |
| Ephemeris | 1-min ephemeris for GOES 8–15 |
Data that were processed for operational use when they were collected.
Operational XRS Data
| Product | Description |
|---|---|
| High Cadence | Full resolution (2 or 3 s cadence) data in daily files in NetCDF and CSV formats |
| Averages | Time-averaged data in monthly files in NetCDF and CSV formats |
| Plots | |
| Housekeeping | Temperatures and other housekeeping data for XRS and EUVS |
Operational EUVS Data
| Product | Description |
|---|---|
| Raw 10-s EUV | Counts and flags for all 5 EUVS channels |
Energetic Particle Sensor (EPS)
Solid-state detectors with pulse-height discrimination measure proton, alpha-particle, and electron fluxes. The EPS telescope (channels P1-P3) and the dome D5 detector designs (channels P6 and P7) were the same from GOES-4 through GOES-15. The dome D3 (channels P4, E1, and E2) and dome D4 detector designs (channels P5 and E3) were the same from GOES-8 through GOES-15.
The E1, E2, E3, and P1 channels respond to trapped outer radiation belt particles. The P2 channel may occasionally respond to trapped particles during magnetically disturbed conditions. P1–P7 measure fluxes that originate outside the magnetosphere–from the sun or the heart of the galaxy. Similarly, the alpha particle channels A1–A6 measures solar- and galactic-origin helium-4 nuclei.
The particle data also include significant secondary responses from higher energy particles, other species (especially proton contamination of electron channels E2 and E3), and directions outside the nominal detector entrance aperture. The data also include backgrounds that are caused by instrument noise, not by penetrating radiation. The integral proton fluxes are derived from the instrument channels and have been partially corrected for these effects. E2 (>2 MeV) and E3 (>4 MeV) electron data become unreliable during most solar energetic particle events (solar radiation storms). The alpha particle (helium-4 nuclei) channels are all differential channels.
On GOES 13–15, the EPS was renamed the Energetic Proton, Electron and Alpha Detector (EPEAD), and two new instruments (Magnetospheric Electron Detector (MAGED), and Magnetospheric Proton Detector (MAGPD)) were added to the suite. MAGED (30-600 keV electrons) and MAGPD (80-800 keV protons) are based on the POES SEM-2 Medium Energy Proton and Electron Detector (MEPED) electron and proton telescope designs, but with different energy channels. MAGED and MAGPD are each composed of nine telescopes of identical design in a cruciform arrangement, with five telescopes forming a fan in the north-south plane and four additional telescopes forming an east-west fan with the central telescope.
High Energy Proton and Alpha Detector (HEPAD)
The HEPAD telescope consists of two silicon detectors and a photomultiplier tube (PMT) illuminated by a Cherenkov radiator. Triple coincidences between the two silicon detectors and the PMT are used to produce four proton channels and two alpha particle channels. There are three proton differential channels between 330 and 700 MeV and an integral channel above 700 MeV. The two alpha particle channels rarely report fluxes above backgrounds. HEPAD data are available from GOES-6 and GOES 8-15 (The GOES-7 instrument failed). The GOES-6 HEPAD first observed a SEP event with a ground level enhancement (GLE) in February 1984 (GLE 39). The final GLE observed by HEPAD (on GOES 13–15) was GLE 72 (September 2017).
When available, we strongly recommend using the science quality data in your study. These data have been reprocessed to account for new calibrations, to account for dead time, or to flag backgrounds and contamination. NCEI has also calculated pitch angles for MAGED and MAGPD.
All Science Quality Particle Data
1-Minute Averages
The 1-minute averages of the GOES 13–15 EPEAD >0.8 and >2 MeV electron channels (E1 and E2) were reprocessed by NCEI with a science-quality algorithm. Key aspects of this algorithm that distinguished this product from the real-time SWPC product included (1) application of a dead-time correction and (2) replacing near-background values with fill values.
Data and Documentation
The 1-minute average particle data can be accessed from the GOES-SEM averages directory. They are contained in the NetCDF folders for GOES 13–15, and use the following file naming convention: g1s_epead_e13ew_1m_20yymm01_20yymmdd_science_v1.0.0.nc.
The GOES EPEAD Science-Quality Electron Fluxes Algorithm Theoretical Basis Document provides a detailed description of the science-quality algorithm and product.
Pitch Angles
Pitch angles for the GOES 13–15 MAGED and MAGPD instruments were calculated at 1-minute cadence by NCEI using magnetic field measurements from the GOES 13–15 magnetometers.
Data and Documentation
The pitch angles for particle data can be accessed from the GOES-SEM averages directory. They are contained in the NetCDF folders for GOES 13–15, and use the following file naming convention: g1s_epead_e13ew_1m_20yymm01_20yymmdd_science_v1.0.0.nc.
The GOES 13–15 MAGE/PD Pitch Angles Algorithm Theoretical Basis Document provides a detailed description of the science-quality algorithm and product.
| Product | Description |
|---|---|
| High Cadence | Full resolution data in daily files in NetCDF and CSV formats |
| SEM GOES Data Averages | Time-averaged data in monthly files in NetCDF and CSV formats |
| SEM GOES Data Plots | |
| SEM GOES Data Ephemeris | Satellite locations for GOES 8-15 |
Magnetometers
Three orthogonal fluxgate magnetometer elements (only two spinning fluxgate elements prior to GOES-8 - 1994) provide geomagnetic field measurements at geosynchronous orbit (L = 6.6) with high resolution since 1974.
More Information About Magnetometers
Science Quality Data
When available, we strongly recommend using the science quality data in your study. These data have been reprocessed to account for new calibration.
Operational Data
| Product | Description |
|---|---|
| High Cadence | Full resolution data in daily files in NetCDF and CSV formats |
| Averages | Time-averaged data in monthly files in NetCDF and CSV formats |
| Plots | |
| Ephemeris | Satellite locations for GOES 8-15 |
Solar X-ray Imager (SXI)
The GOES 12 through 15 spacecraft each carried an X-ray telescope called the Solar X-ray Imager (SXI) to monitor the solar corona. SXI used a 512 x 512 intensified CCD and broadband filters to obtain images at several wavelength bands between about 6 and 60 Å.
Operational Data
| Product | Description |
|---|---|
| High Cadence | Full resolution data in daily files in NetCDF and CSV formats |
| SEM GOES Data Averages | Time-averaged data in monthly files in NetCDF and CSV formats |
| SEM GOES Data Plots | |
| SXI |
GOES Science-Quality Data
- GOES 13–15 Science-Quality EUVS Data Readme
- GOES XRS Science-Quality Data Readme
- GOES XRS Level 2 User Guide
- GOES 8–15 Ephemeris Data ReadMe
- GOES 8–15 Magnetometer Readme
- EUVS Responsivity
- XRS Responsivity
GOES Operational (Real-Time) Data Readmes
- GOES 1-15 Operational XRS Data Readme
- Readme for pre-GOES-13 NOP averaged data
- Readme for SMS-1 through GOES-7 Full Resolution Data
- SXI Readme
GOES Data Books: Overview of the Satellite Platform and Instruments
GOES NOP (13–15) Algorithm Theoretical Basis Documents
- GOES EPEAD Science-Quality Electron Fluxes Algorithm Theoretical Basis Document
- GOES 13-15 MAGE/PD Pitch Angles Algorithm Theoretical Basis Document
GOES NOP (13–15) Engineering Documents
- Electron Calibration Report for EPEAD D3 Dome (2004)
- Electron Calibration Report for MAGED Telescope (2004)
- Proton and Electron Calibration Report for MAGPD Telescope (2004)
- EPS/HEPAD Calilbration and Data Handbook (2011)
- GOES-NOP HEPAD In-Orbit Data Study (2011)
GOES I-M (8–12) Engineering Documents
- EPS Dome Electron Channel Calibration Report (1988)
- EPS Dome Sensor Response to Protons (1995)
- Proton Calibration of HEPAD (1990)
- GOES-G XRS Calibration Document-02 (Jan 1, 985)
- GOES I–M Calibration Document-06 (May, 1986)
- GOES I–M Calibration Document-07 (May, 2000)
GOES DEF (4–6) Engineering Documents
- EPS Telescope Calibration Work (1979)
- EPS Dome Calibration Work (1980)
- Proton Calibration of HEPAD (1986)
- HEPAD Preliminary Data Analysis (1980)
- XRS/EPS Sensor Operation Document-01 (Feb, 1987)
- XRS Calibration Document-03 (May. 1980)
- GOES D Calibration Document-04 (May, 1980)
- GOES E XRS Calibration Document-05 (Feb, 1980)
GOES 1–3 and SMS Engineering Documents
- ERL-SEL-42: Space Environment Subsystem, 1975, R.N. Grubb
- ERL-SEL-48: Solar X-ray Measurements from SMS-1, SMS-1 and GOES-1, Information for Data Users, R.F. Donnelly, et al
- ERL-SEL-56: SMS-GOES Soft X-ray Measurements, July 1, 1974 - December 31, 1976, R.F. Donnelly
Important GOES Data Announcements
- GOES-14 and 15 Data Discontinuation Announcement (March 4, 2020)
- GOES-13 Data Discontinuation Announcement (December 14, 2017)
Other Documents
- Data Notes: Historical data quality issues are discussed.
- GOES-NOP_QualFlag_Dictionary_v20100218.xls
- GOES-NOP_QualFlag_Dictionary_v20110309.xls
- goes13ReadinessReview-Particles.pdf
- GOES-13_QualityIssues_v20100322.pdf
- Solar Proton Events Affecting the Earth Environment
- EGU2017 - GOES-8-15 HiRes and ULFs - Redmon.pptx
- ERL-SEL-62: A Summary of Solar 1-8 Å Measurements from the SMS and GOES Satellites, 1977 - 1981, S.D. Bouwer, et al
- Monitoring Space Weather with the GOES Magnetometers, SPIE Conference, H.J. Singer, et al
- Comment on the use of GOES Solar Proton Data and Spectra in Solar Proton Dose Calculations, D.F. Smart & M.A. Shea.
- The NORAD orbital elements for GOES are available from CelestraK.
- Software for early full resolution data: Convert FITS Binary Tables to ASCII tables.
- The Moon: SXI images of the moon
- 2010 GOES and POES Data Services Program Review Slides
