scholarly journals Lunar Calibration for ASTER VNIR and TIR with Observations of the Moon in 2003 and 2017

2019 ◽  
Vol 11 (22) ◽  
pp. 2712 ◽  
Author(s):  
Kouyama ◽  
Kato ◽  
Kikuchi ◽  
Sakuma ◽  
Miura ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Near Infrared ◽  
Thermal Emission ◽  
Thermal Infrared ◽  
Calibration Method ◽  
The Other ◽  
Radiometric Calibration ◽  
The Moon ◽  
Calibration Methods ◽  
Better Than

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which is a multiband pushbroom sensor suite onboard Terra, has successfully provided valuable multiband images for approximately 20 years since Terra’s launch in 1999. Since the launch, sensitivity degradations in ASTER’s visible and near infrared (VNIR) and thermal infrared (TIR) bands have been monitored and corrected with various calibration methods. However, a unignorable discrepancy between different calibration methods has been confirmed for the VNIR bands that should be assessed with another reliable calibration method. In April 2003 and August 2017, ASTER observed the Moon (and deepspace) for conducting a radiometric calibration (called as lunar calibration), which can measure the temporal variation in the sensor sensitivity of the VNIR bands enough accurately (better than 1%). From the lunar calibration, 3–6% sensitivity degradations were confirmed in the VNIR bands from 2003 to 2017. Since the measured degradations from the other methods showed different trends from the lunar calibration, the lunar calibration suggests a further improvement is needed for the VNIR calibration. Sensitivity degradations in the TIR bands were also confirmed by monitoring the variation in the number of saturated pixels, which were qualitatively consistent with the onboard and vicarious calibrations.

Uncertainty Evaluations of the CRCS In-orbit Field Radiometric Calibration Methods for Thermal Infrared Channels of FENGYUN Meteorological Satellites

2020 ◽  
Author(s):  
Yong Zhang ◽  
Zhiguo Rong ◽  
Xiaopeng Hao
Keyword(s):  
Field Measurements ◽  
Thermal Infrared ◽  
Calibration Method ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiometric Calibration ◽  
Brightness Temperatures ◽  
Calibration Methods ◽  
Disaster Monitoring ◽  
Better Than

<p>Meteorological satellites have become an irreplaceable weather and ocean-observing tool in China. These satellites are used to monitor natural disasters and improve the efficiency of many sectors of Chinese national economy. It is impossible to ignore the space-derived data in the fields of meteorology, hydrology, and agriculture, as well as disaster monitoring in China, a large agricultural country. For this reason, China is making a sustained effort to build and enhance its meteorological observing system and application system. The first Chinese polar-orbiting weather satellite was launched in 1988. Since then China has launched 17 meteorological satellites, 8 of which are sun synchronous and 9 of which are geostationary satellites; China will continue its two types of meteorological satellite programs.</p><p>In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites’ thermal infrared channels, China radiometric calibration sites (CRCS) established a set of in-orbit field absolute radiometric calibration methods (FCM) for thermal infrared channels (TIR) and the uncertainty of this method was evaluated and analyzed based on TERRA/AQUA MODIS observations. Comparisons between the MODIS at pupil brightness temperatures (BTs) and the simulated BTs at the top of atmosphere using radiative transfer model (RTM) based on field measurements showed that the accuracy of the current in-orbit field absolute radiometric calibration methods was better than 1.00K (@300K, K=1) in thermal infrared channels. Therefore, the current CRCS field calibration method for TIR channels applied to Chinese metrological satellites was with favorable calibration accuracy: for 10.5-11.5µm channel was better than 0.75K (@300K, K=1) and for 11.5-12.5µm channel was better than 0.85K (@300K, K=1).</p>

scholarly journals An overview of in-orbit radiometric calibration of typical satellite sensors

2015 ◽  
Vol XL-7/W4 ◽  
pp. 235-240 ◽  
Author(s):  
G. Q. Zhou ◽  
C. Y. Li ◽  
T. Yue ◽  
L. J. Jiang ◽  
N. Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Calibration Method ◽  
Radiometric Calibration ◽  
Infrared Band ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Calibration Methods ◽  
Satellite Sensors ◽  
Similarities And Differences ◽  
Typical Satellite

This paper reviews the development of in-orbit radiometric calibration methods in the past 40 years. It summarizes the development of in-orbit radiometric calibration technology of typical satellite sensors in the visible/near-infrared bands and the thermal infrared band. Focuses on the visible/near-infrared bands radiometric calibration method including: Lamp calibration and solar radiationbased calibration. Summarizes the calibration technology of Landsat series satellite sensors including MSS, TM, ETM+, OLI, TIRS; SPOT series satellite sensors including HRV, HRS. In addition to the above sensors, there are also summarizing ALI which was equipped on EO-1, IRMSS which was equipped on CBERS series satellite. Comparing the in-orbit radiometric calibration technology of different periods but the same type satellite sensors analyzes the similarities and differences of calibration technology. Meanwhile summarizes the in-orbit radiometric calibration technology in the same periods but different country satellite sensors advantages and disadvantages of calibration technology.

scholarly journals Vicarious Radiometric Calibration of Ocean Color Bands for FY-3D/MERSI-II at Lake Qinghai, China

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 139
Author(s):  
Shengli Chen ◽  
Xiaobing Zheng ◽  
Xin Li ◽  
Wei Wei ◽  
Shenda Du ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Large Deviation ◽  
Ocean Color ◽  
Calibration Method ◽  
Surface Measurement ◽  
Radiometric Calibration ◽  
Lake Qinghai ◽  
Vicarious Calibration ◽  
Calibration Methods ◽  
Spectral Imager

To calibrate the low signal response of the ocean color (OC) bands and test the stability of the Fengyun-3D (FY-3D)/Medium Resolution Spectral Imager II (MERSI-II), an absolute radiometric calibration field test of FY-3D/MERSI-II at the Lake Qinghai Radiometric Calibration Site (RCS) was carried out in August 2018. The lake surface and atmospheric parameters were mainly measured by advanced observation instruments, and the MODerate spectral resolution atmospheric TRANsmittance algorithm and computer model (MODTRAN4.0) was used to simulate the multiple scattering radiance value at the altitude of the sensor. The results showed that the relative deviations between bands 9 and 12 are within 5.0%, while the relative deviations of bands 8, and 13 are 17.1%, and 12.0%, respectively. The precision of the calibration method was verified by calibrating the Aqua/Moderate-resolution Imaging Spectroradiometer (MODIS) and National Polar-orbiting Partnership (NPP)/Visible Infrared Imaging Radiometer (VIIRS), and the deviation of the calibration results was evaluated with the results of the Dunhuang RCS calibration and lunar calibration. The results showed that the relative deviations of NPP/VIIRS were within 7.0%, and the relative deviations of Aqua/MODIS were within 4.1% from 400 nm to 600 nm. The comparisons of three on-orbit calibration methods indicated that band 8 exhibited a large attenuation after launch and the calibration results had good consistency at the other bands except for band 13. The uncertainty value of the whole calibration system was approximately 6.3%, and the uncertainty brought by the field surface measurement reached 5.4%, which might be the main reason for the relatively large deviation of band 13. This study verifies the feasibility of the vicarious calibration method at the Lake Qinghai RCS and provides the basis and reference for the subsequent on-orbit calibration of FY-3D/MERSI-II.

scholarly journals Radiometric Calibration for Incidence Angle, Range and Sub-Footprint Effects on Hyperspectral LiDAR Backscatter Intensity

2020 ◽  
Vol 12 (17) ◽  
pp. 2855
Author(s):  
Changsai Zhang ◽  
Shuai Gao ◽  
Wang Li ◽  
Kaiyi Bi ◽  
Ni Huang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spatial Information ◽  
Incidence Angle ◽  
Incident Angle ◽  
Calibration Method ◽  
Correction Method ◽  
Intensity Data ◽  
Radiometric Calibration ◽  
Backscatter Intensity ◽  
Reference Target

Terrestrial hyperspectral LiDAR (HSL) sensors could provide not only spatial information of the measured targets but also the backscattered spectral intensity signal of the laser pulse. The raw intensity collected by HSL is influenced by several factors, among which the range, incidence angle and sub-footprint play a significant role. Further studies on the influence of the range, incidence angle and sub-footprint are needed to improve the accuracy of backscatter intensity data as it is important for vegetation structural and biochemical information estimation. In this paper, we investigated the effects on the laser backscatter intensity and developed a practical correction method for HSL data. We established a laser ratio calibration method and a reference target-based method for HSL and investigated the calibration procedures for the mixed measurements of the effects of the incident angle, range and sub-footprint. Results showed that the laser ratio at the red-edge and near-infrared laser wavelengths has higher accuracy and simplicity in eliminating range, incident angle and sub-footprint effects and can significantly improve the backscatter intensity discrepancy caused by these effects.

Framework for Multivariate Selectivity Analysis, Part I: Theoretical and Practical Merits

2005 ◽  
Vol 59 (6) ◽  
pp. 787-803 ◽  
Author(s):  
Christopher D. Brown ◽  
Trent D. Ridder
Keyword(s):  
Near Infrared ◽  
Clinical Laboratory ◽  
Simulated Data ◽  
Calibration Method ◽  
National Committee ◽  
Data Sets ◽  
Calibration Methods ◽  
Inverse Calibration ◽  
The One ◽  
Definition Of

A number of definitions of multivariate selectivity have been proposed in the literature. Arguably, the one that enjoys the greatest chemometric attention has been the net analyte signal (NAS) based definitions of Lorber and Zinn. Recent works have suggested that similar inference can be made for inverse least-squares calibration methods (e.g., principal components regression). However, the properties of inverse calibration methods are markedly different than classical methods, so in many practical cases involving inverse models classically derived figures of merit cannot be transparently interpreted. In Part I of this work, we discuss a selectivity framework that is theoretically consistent regardless of the calibration method. Importantly, it is also experimentally measurable, either through controlled selectivity experiments, or through analysis on opportunistically acquired sample measurements. It is statistically advantageous to use the former if such control is achievable. Selectivity is defined to be a function of the change in predicted analyte concentration that will result from a change in the concentration of an interferant, an approach consistent with traditional definitions of analytical selectivity and National Committee for Clinical Laboratory Standards recommendations for interference testing. Unlike the NAS-based definition of selectivity, the definition discussed herein is relevant to only a particular analyte–interferant pair. The theoretical and experimental aspects of this approach are illustrated with simulated data herein and in Part II of this paper, which investigates several experimental near-infrared data sets.

The Origin of Belief among the Greeks in the Divinity of the Heavenly Bodies

1940 ◽  
Vol 33 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Martin P. Nilsson
Keyword(s):  
The Other ◽  
The Sun ◽  
The Moon ◽  
Wide Spread ◽  
Other Hand ◽  
Foreign Origin ◽  
Of Greece ◽  
Better Than ◽  
Classical Age

It is a fact which is not justly appreciated that the Sun and the Moon had almost no cult in the early and classical age of Greece except for the Sun at Rhodes, a cult which is reasonably suspected to be of foreign origin. Helios and Selene were, of course, considered to be gods, but in mythology. Those scholars who have eagerly tried to find evidence for their cult ought to remember the statements of Aristophanes and Plato that Helios and Selene were barbarous gods. These two certainly knew the cults of their compatriots better than we do. On the other hand, the Sun cult was very popular and wide-spread in Roman times and became finally the last State religion of the Empire. It came from the Orient, and the mediator and the reason of its popularity was astrology. So the question arises: why did the Greeks accept the astrology which they rejected in an earlier age, and why did they begin to pay a cult to Helios to whom they had shown no veneration in earlier times? Did they simply succumb to a foreign religion or were there intrinsic reasons which contributed to this result?

scholarly journals The instrument constant of sky radiometer (POM-02), Part I: Calibration constant

2018 ◽  
Author(s):  
Akihiro Uchiyama ◽  
Tsuneo Matsunaga ◽  
Akihiro Yamazaki
Keyword(s):  
Seasonal Variation ◽  
Near Infrared ◽  
Calibration Method ◽  
Gas Absorption ◽  
Sensor Output ◽  
Correction Factors ◽  
Maximum Difference ◽  
Calibration Constant ◽  
Rms Error ◽  
Better Than

Abstract. Ground-based networks have been developed to determine the spatiotemporal distribution of aerosols using radiometers. In this study, the accuracy of the calibration constant (V0) for the sky radiometer (POM-02) which is used by SKYNET was investigated. The temperature dependence of the sensor output was also investigated, and the dependence in the 340, 380, and 2200 nm channels was found to be larger than for other channels, and varied with the instrument. In the summer, the sensor output had to be corrected by a factor of 1.5 to 2 % in the 340 and 380 nm channels and by 4 % in the 2200 nm channel in the measurements at Tsukuba. In the other channels, the correction factors were less than 0.5 %. The accuracy of V0 from the normal Langley method is between 0.2 and 1.3 %, except in the 940 nm channel. The effect of gas absorption was less than 1 % in the 1225, 1627, and 2200 nm channels. The degradation of V0 for shorter wavelengths was larger than that for longer wavelengths. The accuracy of V0 estimated from the side-by-side measurements was 0.1 to 0.5 %. The V0 determined by the improved Langley (IML) method had a seasonal variation of 1 to 3 %. The RMS error from the IML method was about 0.6 to 2.5 %, and in some cases, the maximum difference reached 5 %. The trend in V0 after removing the seasonal variation was almost the same as for the normal Langley method. The calibration method for water vapor in the 940 nm channel was developed using an empirical formula for transmittance. The accuracy of V0 was better than 1 % on relatively stable and fine days. A calibration method for the near-infrared channels, 1225, 1627, and 2200 nm, was also developed. The logarithm of the ratio of the sensor output can be written as a linear function of the airmass, by assuming that the ratio of the optical thicknesses between the two channels is constant. The accuracy of V0 was better than 1 % on days with good conditions.

scholarly journals Time Variation of the Solar Dust Cloud

1996 ◽  
Vol 150 ◽  
pp. 353-356 ◽  
Author(s):  
H. Kimura
Keyword(s):  
Temporal Variation ◽  
Size Distribution ◽  
Near Infrared ◽  
Thermal Emission ◽  
Scattered Light ◽  
Dust Cloud ◽  
Line Of Sight ◽  
Dust Grains ◽  
Infrared Wavelengths ◽  
Potential Origin

AbstractWe have found from line-of-sight integration of scattered light and thermal emission that the appearance of a hump in the F-corona, which was observed in the near-infrared wavelengths by Peterson (1969) and MacQueen (1968), is very sensitive to the change of size distribution of circumsolar dust grains. Namely, the size distribution affects the balance of scattered sunlight and thermal emission. We suggest that a temporal variation in the size distribution of circumsolar dust grains is a potential origin of the temporal variation of the hump structure observed in the F-corona.

Analysis of EPDM Terpolymers by Near-Infrared Spectroscopy and Multivariate Calibration Methods

1989 ◽  
Vol 43 (8) ◽  
pp. 1435-1443 ◽  
Author(s):  
Charles E. Miller
Keyword(s):  
Infrared Spectroscopy ◽  
Least Squares ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Multivariate Calibration ◽  
Calibration Method ◽  
Chemical Components ◽  
Multivariate Methods ◽  
Calibration Methods ◽  
Interchain Interactions

Near-infrared spectroscopy in the combination, first overtone, and second overtone regions is combined with the multivariate methods of Partial-Least-Squares (PLS) and Classical-Least-Squares (CLS) to provide calibrations for chemical components in ethylene-propylene-diene monomer (EPDM) terpolymers. EPDM samples with 1,4-hexadiene (HD) and ethylidene norbornene (ENB) diene monomers were used for this study. Because unknown interaction effects are present in the spectra of these materials, the PLS calibration method gives more accurate calibrations than the CLS method. PLS coefficient spectra and CLS reconstructed spectra obtained from the calibrations are used to determine the sources of the unknown spectral effects. Results indicate that the combination, first overtone, and second overtone regions of the spectrum can be used to determine ethylene and propylene concentrations in the terpolymers, and the combination region can be used to determine diene concentrations. The presence of intrachain and interchain interactions in the terpolymers is indicated by observation of CLS reconstructed spectra.

scholarly journals Radiometric Degradation Curves for the ASTER VNIR Processing Using Vicarious and Lunar Calibrations

2020 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Satoshi Tsuchida ◽  
Hirokazu Yamamoto ◽  
Toru Kouyama ◽  
Kenta Obata ◽  
Fumihiro Sakuma ◽  
...  
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Thermal Infrared ◽  
Vicarious Calibration ◽  
The Cross ◽  
Sensor Degradation ◽  
Cross Calibration ◽  
Shortwave Infrared ◽  
Infrared Radiometer

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard Terra platform, which was launched in 1999, has three separate subsystems: a visible and near-infrared (VNIR) radiometer, a shortwave-infrared radiometer, and a thermal-infrared radiometer. The ASTER VNIR bands have been radiometrically corrected for approximately 14 years by the sensor degradation curves estimated from the onboard calibrator according to the original calibration plan. However, this calibration by the onboard calibrator encountered a problem; specifically, it is inconsistent with the results of vicarious calibration and cross calibration. Therefore, the ASTER VNIR processing was applied by the radiometric degradation curves calculated from the results of three calibration approaches, i.e., the onboard calibrator, the vicarious calibration, and the cross calibration since February 2014. Even though the current degradation curves were revised, the inter-band and lunar calibrations show some inconsistencies owing to the different traceability in the bands by different calibration approaches. In this study, the current degradation curves and their problems are explained, and the new curves that are derived from the vicarious calibration with lunar calibration are discussed. The new degradation curves that have the same traceability in the bands will be used for future ASTER VNIR processing.

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