Comparison of the NBS SURF and tungsten ultraviolet irradiance standards

Kostkowski, Henry J.; Lean, J.; Saunders, Robert D.; Hughey, L. R.

doi:10.1364/ao.25.003297

Cited by 17 publications

(13 citation statements)

References 2 publications

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“…the ATLAS 1 SSBUV spectrum and the UARS average spectrum(Figure 7c)shows differences well below the total uncertainty level. This result confirms previous assertions[Kostkowski et al, 1986] that the various NIST radiometric standards are consistent to within 2%, because theSSBUV uses primarily the NIST FEL and D2 lamps for calibra-UARS level 3BS data comparison. The ratios of the UARS SUSIM level 3BS data to the UARS SOLSTICE level 3BS data are at 1-and 3-nm resolutions inFigures 8a and 8b, respectively.…”

supporting

confidence: 90%

“…The FEL lamps are the primary standards used to calibrate SSBUV in the wavelength region 250 to 405 nm, with an absolute 20 accuracy of 1•1 to 1.9% [Walker e• al., 1987]. The SSBUV is calibrated against spectral irradiance lamps rather than SURF II, which is the primary standard for the other three instrumentso Hence any absolute or spectral bias between SURF II and the lamp standards should result in a difference between the irradiances measured by SSBUV and the other instruments, but only at the 1 to 2% level [Kostkowski et al, 1986]…”

Section: Uars Solsticementioning

confidence: 99%

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Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements

Woods¹,

Prinz²,

Rottman³

et al. 1996

J. Geophys. Res.

348

171

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The measurements of the solar ultraviolet spectral irradiance made by the two Upper Atmosphere Research Satellite (UARS) solar instruments, Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) and SOLar STellar Irradiance Comparison Experiment (SOLSTICE), are compared with same‐day measurements by two solar instruments on the shuttle ATmospheric Laboratory for Applications and Science (ATLAS) missions, ATLAS SUSIM and Shuttle Solar Backscatter UltraViolet (SSBUV) experiment. These measurements from the four instruments agree to within the 2σ uncertainty of any one instrument, which is 5 to 10% for all wavelengths above 160 nm and for strong emission features below 160 nm. Additionally, the long‐term relative accuracy of the two UARS data sets is better than the original 2% goal, especially at wavelengths greater than 160 nm. This level of agreement is credited to accurate preflight calibrations coupled with comprehensive inflight calibrations to track instrument degradation. Two solar irradiance spectra, 119 to 410 nm, are presented; the first combines observations from UARS SUSIM and UARS SOLSTICE taken on March 29, 1992, during the ATLAS 1 mission, and the second combines spectra for April 15, 1993, during the ATLAS 2 mission. The ATLAS 1 mission coincided with the initial decline from the maximum of solar cycle 22 when solar activity was relatively high. The ATLAS 2 mission occurred somewhat later during the declining phase of the solar cycle 22 when solar activity was more moderate.

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supporting

confidence: 90%

Section: Uars Solsticementioning

confidence: 99%

Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements

Woods¹,

Prinz²,

Rottman³

et al. 1996

J. Geophys. Res.

348

171

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“…Improving measurement accuracies is a difficult radiometric problem, involving (1) verifying the laboratory irradiance standards, (2) transferring the accuracy of these standards to the measuring instrument, and (3) knowing the instrument responsivity at the actual time of the measurement. Kostkowski et al [1986] have re•cently compared the NBS SURF-II and FEL tungsten quartz halogen irradiance standards at 297 nm, and they find an agreement of 1%, which is within the combined uncertainties of the standards (0.7% and 2.0% for SURF-II and FEL, respectively, at 297 nm). Preliminary results also indicate agreement between SURF and the argon miniarc at 213 nm, to within their combined uncertainties (see Madden [1977a, b] for a summary of the NBS radiometric standards).…”

Section: Consistent Inmentioning

confidence: 60%

Solar ultraviolet irradiance variations: A review

Lean¹

1987

J. Geophys. Res.

280

132

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Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short‐term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11‐year solar cycle. The comparative importance for the long‐term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground‐based measures of solar variability are examined because of the importance of the ground‐based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described.

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“…The wavelength of the recorded signal depends on the orientation of the grating; the strength of the recorded signal depends on many factors pertaining to the radiation source (the magnitude, polarization, and direction of the emitted rays), to the spectrometer (the dependence of the responsivity on the magnitude, polarization, and direction on the incident rays), and to certain environmental conditions (such as the presence of external stray radiations, temperature, and the diffracting medium). Becaiase laboratory UV irradiance sources used for instrument calibration purposes may be quite different, radiometrically, from the Sun, the dependence of the instrument signal on these radiometric differences must be thoroughly characterized so that calibration errors arising from these differences are minimized and can be evaluated [Kostkowski et al, 1986;Lean et al, 1989]. Differences in relative spectral distributions and flux magnitude are illustrated in Figure 5.…”

Section: Radiometric Characterization Of Susim-uarsmentioning

confidence: 99%

The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) experiment on board the Upper Atmosphere Research Satellite (UARS)

Brueckner¹,

et al. 1993

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The state of solar ultraviolet irradiance measurements in 1978, when NASA requested proposals for a new generation of solar ultraviolet monitors to be flown on the Upper Atmosphere Research Satellite (UARS), is described. To overcome the radiometric uncertainties that plagued the measurements at this time, the solar ultraviolet spectral irradiance monitor (SUSIM) instrument design included in‐flight calibration light sources and multichannel photometers. Both are aimed at achieving a maximum precision of the SUSIM measurements over a long period of time, e.g., one solar cycle. The design of the SUSIM‐UARS instrument is compared with the original design specifications for the UARS instruments. Details including optical train, filters, detectors, and contamination precautions are described. Also discussed are the SUSIM‐UARS preflight calibration and characterization, as well as the results of the inflight performance of the instrument during the first 3 months of operation. Finally, flight operations, observation strategy, and data reduction schemes are outlined.

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Comparison of the NBS SURF and tungsten ultraviolet irradiance standards

Cited by 17 publications

References 2 publications

Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements

Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements

Solar ultraviolet irradiance variations: A review

The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) experiment on board the Upper Atmosphere Research Satellite (UARS)

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