------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: TSIS-1 SIM Version 04 (V04) Solar Spectral Irradiance (SSI) 2. Authors: Erik Richard, Michael Chambliss, Steven Penton, Stéphane Béland, Laura Sandoval, Gavin Medley, Luke Charbonneau 3. Contact information: Michael.Chambliss@lasp.colorado.edu 4. Date of data collection: March 14, 2018 to November 07, 2020 -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: None 2. Links to publications that cite or use the data: "SORCE and TSIS-1 SIM Comparison: Absolute Irradiance Scale Reconciliation" [Paper #2021EA002122R] in Earth and Space Science, in production. DOI: 10.1029/2021EA002122 3. Links to other publicly accessible locations of the data: None 4. Recommended citation for the data: Erik Richard (2020), Level 3 Solar Spectral Irradiance 12-Hourly Means V04, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC) --------------------- DATA & FILE OVERVIEW --------------------- 1. File List: A. Filename: TSIS_SIM_V04_Release_Notes.pdf B. Filename: tsis_ssi_L3_c12h_v04_20180314_20201107.txt C. Filename: tsis_ssi_L3_c24h_v04_20180314_20201107.txt D. Filename: tsis_ssi_L3_c12h_v04_20180314_20201107.sav E. Filename: tsis_ssi_L3_c24h_v04_20180314_20201107.sav F. Filename: tsis_ssi_L3_c12h_v04_20180314_20201107.nc G. Filename: tsis_ssi_L3_c24h_v04_20180314_20201107.nc 2. Relationship between files: TSIS_SIM_V04_Release_Notes.pdf contains the L3 data release notes of V04 of the TSIS-1 SIM Solar Spectral Irradiance. Data is released in 12-hour and 24-hour cadence in ASCII (.txt), NetCDF (.nc), and IDL SAVfile format (.sav). -------------------------- METHODOLOGICAL INFORMATION -------------------------- NASA's Total and Spectral Solar Irradiance Sensor -1 (TSIS-1) operates on the International Space Station. TSIS-1 provides absolute measurements of the total solar irradiance (TSI) and spectral solar irradiance (SSI), important for accurate scientific models of climate change and solar variability. TSIS-1 is comprised of two instruments, the Total Irradiance Monitor (TIM), and the Spectral Irradiance Monitor (SIM) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c12h_v04_20180314_20201107.txt ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 3120158 3. Variable List: A. Name: nominal_date_yyyymmdd, R8, f11.2 Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, R8, f11.2 Description: Julian Date of measurement. 12-hour data are on 0.25 or 0.75 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, R4, f9.3 (nm) Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, I2, i3 Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, I2, i3 Description: Version of data release. F. Name: irradiance_1AU, R8, e15.8 (W/m^2/nm) Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UI2, i6 Description: Level 3 data quality flag. A quality flag of '0' indicates good data, '1' indicates missing data, irradiance values with a missing data flag are given as 0.0, and '2' indicates data that has been backfilled from the previous day. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c24h_v04_20180314_20201107.txt ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 1681232 3. Variable List: A. Name: nominal_date_yyyymmdd, R8, f11.2 Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, R8, f11.2 Description: Julian Date of measurement. 24-hour data are on 0.5 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, R4, f9.3 (nm) Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, I2, i3 Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, I2, i3 Description: Version of data release. F. Name: irradiance_1AU, R8, e15.8 (W/m^2/nm) Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UI2, i6 Description: Level 3 data quality flag. A quality flag of '0' indicates good data, '1' indicates missing data, irradiance values with a missing data flag are given as 0.0, and '2' indicates data that has been backfilled from the previous day. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c12h_v04_20180314_20201107.sav ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 3120158 3. Variable List: Data is stored in an IDL structure named "DATA". Description in the string array "DOC_SIM". A. Name: nominal_date_yyyymmdd, DOUBLE Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, DOUBLE Description: Julian Date of measurement. 12-hour data are on 0.25 or 0.75 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, FLOAT Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, INT Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, INT Description: Version of data release. F. Name: irradiance_1AU, DOUBLE Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, DOUBLE (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability,DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UINT Description: Level 3 data quality flag. A quality flag of '0' indicates good data, '1' indicates missing data, irradiance values with a missing data flag are given as 0.0, and '2' indicates data that has been backfilled from the previous day. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c24h_v04_20180314_20201107.sav ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 1681232 3. Variable List: Data is stored in an IDL structure named "DATA". Description in the string array "DOC_SIM". A. Name: nominal_date_yyyymmdd, DOUBLE Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, DOUBLE Description: Julian Date of measurement. 24-hour data are on 0.5 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, FLOAT Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, INT Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, INT Description: Version of data release. F. Name: irradiance_1AU, DOUBLE Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, DOUBLE (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability,DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UINT Description: Level 3 data quality flag. A quality flag of '0' indicates good data, '1' indicates missing data, irradiance values with a missing data flag are given as 0.0, and '2' indicates data that has been backfilled from the previous day. 4. Data codes (e.g., N/A = Not applicable):