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 Calibration Method of Low-Light Sensor Based on Bridge Lights

2016 ◽  
Vol 33 (6) ◽  
pp. 1123-1134 ◽  
Author(s):  
Shuo Ma ◽  
Wei Yan ◽  
Yunxian Huang ◽  
Jun Jiang ◽  
Shensen Hu ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Calibration Method ◽  
High Gain ◽  
Hangzhou Bay ◽  
Radiometric Calibration ◽  
Low Light ◽  
Invariant Surface ◽  
Vicarious Calibration ◽  
Calibration Methods ◽  
Gain Stage

AbstractMany quantitative uses of the nighttime imagery provided by low-light sensors, such as the day–night band (DNB) on board the Suomi–National Polar-Orbiting Partnership (SNPP), have emerged recently. Owing to the low nighttime radiance, low-light calibration at night must be investigated in detail. Traditional vicarious calibration methods are based on some targets with nearly invariant surface properties under lunar illumination. However, the relatively stable light emissions may also be used to realize the radiometric calibration under low light. This paper presents a low-light calibration method based on bridge lights, and Visible Infrared Imaging Radiometer Suite (VIIRS) DNB data are used to assess the proposed method. A comparison of DNB high-gain-stage (HGS) radiances over a 2-yr period from August 2012 to July 2014 demonstrates that the predictions are consistent with the observations, and the agreement between the predictions and the observations is on the order of −2.9% with an uncertainty of 9.3% (1σ) for the Hangzhou Bay Bridge and −3.9% with an uncertainty of 7.2% (1σ) for the Donghai Bridge. Such a calibration method based on stable light emissions has a wide application prospect for the calibration of low-light sensors at night.

scholarly journals FY-3D MERSI On-Orbit Radiometric Calibration from the Lunar View

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4690 ◽  
Author(s):  
Ronghua Wu ◽  
Peng Zhang ◽  
Na Xu ◽  
Xiuqing Hu ◽  
Lin Chen ◽  
...  
Keyword(s):  
Large Deviation ◽  
Calibration Method ◽  
Earth Observation ◽  
Observation Data ◽  
Radiometric Calibration ◽  
Medium Resolution ◽  
Laboratory Calibration ◽  
Earth Observation Satellites ◽  
Spectral Imager ◽  
Single Pixel

Limited by the on-orbital calibration capability, scaling the measured radiance in accuracy and stability is challenging for the Earth observation satellites in the reflective solar bands (RSBs). Although the lunar calibration is a well-developed technique in the RSBs, limited work has been done for Chinese Earth observation satellites. To improve the on-orbital calibration performance, the advanced MEdium Resolution Spectral Imager (MERSI II), which is the primary payload of the fourth satellite of the Fengyun 3 Series (FY-3D), expands the space view angle of the imager in order to capture better lunar images. In this study, we propose an absolute radiometric calibration method based on the FY-3D/MERSI lunar observation data. A lunar irradiance model named ROLO/GIRO has been used together with the necessary data procedures, including dark current count estimation, single pixel irradiance calculation, and full disk lunar irradiance calculation. The calibration coefficients obtained by the lunar calibration are compared with the pre-launch laboratory calibration. The results show that the deviations between the two calibration procedures are in a reasonable range in general. However, a relatively high non-linear response was found in the low energy incidence for some detectors, which leads to the large deviation in the corresponding bands. This study explored an ideal and independent method to validate MERSI on-orbit radiometric performance. The lunar calibration practiced for MERSI also gave a valuable example that can be recommended to the other Chinese Earth observation satellites.

An In-Orbit Radiometric Calibration Method of the Geostationary Ocean Color Imager

2010 ◽  
Vol 48 (12) ◽  
pp. 4322-4328 ◽  
Author(s):  
Geumsil Kang ◽  
Pierre Coste ◽  
Heongsik Youn ◽  
Francois Faure ◽  
Seongbong Choi
Keyword(s):  
Ocean Color ◽  
Calibration Method ◽  
Radiometric Calibration

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.

scholarly journals Vicarious Calibration of FengYun-3D MERSI-II at Railroad Valley Playa Site: A Case for Sensors with Large View Angles

2021 ◽  
Vol 13 (7) ◽  
pp. 1347
Author(s):  
Yepei Chen ◽  
Kaimin Sun ◽  
Wenzhuo Li ◽  
Xiuqing Hu ◽  
Pengfei Li ◽  
...  
Keyword(s):  
Field Measurements ◽  
Calibration Method ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiometric Calibration ◽  
Vicarious Calibration ◽  
In Situ Data ◽  
Benchmark Datasets ◽  
Moderate Resolution Imaging Spectroradiometer

Vicarious calibration, as one on-orbit calibration method, is a supplement to onboard calibration of sensors. The application of vicarious calibration, however, is greatly limited due to the time- and effort-consuming field measurements of atmosphere and surface. Fortunately, the Radiometric Calibration Network (RadCalNet) provides automated in situ data at multiple sites, thus increasing the opportunities to achieve ongoing ground-reference calibration of in-orbit instruments. The MEdium Resolution Spectrum Imager-II (MERSI-II) onboard FengYun-3D (FY) has the temporal, spectral, spatial, and radiometric capacity for image capture at a level on par with other sensors used worldwide, such as the Moderate Resolution Imaging Spectroradiometer (MODIS). Its on-orbit radiometric performance, however, is assessed in a limited manner. In this study, the reflectance-based vicarious calibration method was employed to calibrate the MERSI-II sensor using ground measurements from RadCalNet at the Railroad Valley Playa site. The calibration of the MERSI-II sensor with large view angles presents difficulties due to the uncertainties introduced by surface bidirectional reflectance distribution function (BRDF) effects. Thus, we performed BRDF correction to harmonize the sensor and ground measurements to consistent observation geometries, before the in-situ measurements were taken as inputs for the 6SV radiative transfer model to predict at-sensor radiance. The calibration results were comprehensively validated with ground data and MODIS benchmark datasets. The results show that accounting for BRDF correction could improve the accuracy of vicarious calibration and ensure inter-consistency between different sensors. An analysis of the vicarious calibration of FY-3D MERSI-II yielded uncertainties of <5% for solar reflective bands, which meets the radiometric accuracy requirements typical for land-monitoring space missions. The proposed approach is also applicable to the calibration of other large footprint sensors.

scholarly journals Radiometric Calibration Evaluation for FY3D MERSI-II Thermal Infrared Channels at Lake Qinghai

2021 ◽  
Vol 13 (3) ◽  
pp. 466
Author(s):  
Lin Yan ◽  
Yonghong Hu ◽  
Yong Zhang ◽  
Xiao-Ming Li ◽  
Changyong Dou ◽  
...  
Keyword(s):  
Brightness Temperature ◽  
Land Surface ◽  
Field Measurements ◽  
Thermal Infrared ◽  
Calibration Coefficient ◽  
Wave Radiation ◽  
Radiometric Calibration ◽  
Atmospheric Conditions ◽  
Lake Qinghai ◽  
Vicarious Calibration

The absolute radiometric accuracy of the Fengyun 3D advanced Medium Resolution Spectral Imager (FY3D MERSI-II) thermal infrared bands was evaluated using the collected field measurements and atmospheric transfer simulations during 16–22 August 2019 at Lake Qinghai. A thermal infrared radiometer equipped on an unmanned surface vehicle was used to continuously collect the water temperature. Atmospheric conditions, surface emissivity, and aerosol optical depth measured near the field experiment site were adopted by the atmospheric transfer code to calculate the parameters about the influence of atmosphere on long-wave radiation, including the path radiance and the transmittance propagated from land surface to the satellite. The radiometric calibration accuracy analysis suggests that the differences between the simulated brightness temperature and satellite-based brightness temperature are −0.346 K and −0.722 K for channel 24 on 18 and 20 August, respectively, while it reaches −0.460 K and −1.036 K for channel 25 on 18 and 20 August, respectively. The vicarious calibration coefficients were found to be in good agreement with the internal onboard calibration coefficient in channel 24 and 25 of the FY3D MERSI-II according to the validation analysis in selected regions. The thermal infrared bands of the FY3D have a good in-orbit operational status according to our vicarious calibration experiments.

scholarly journals Preliminary Selection and Characterization of Pseudo-Invariant Calibration Sites in Northwest China

2020 ◽  
Vol 12 (16) ◽  
pp. 2517
Author(s):  
Xiuqing Hu ◽  
Ling Wang ◽  
Junwei Wang ◽  
Lingli He ◽  
Lin Chen ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Temporal Stability ◽  
Selection Procedure ◽  
Northwest China ◽  
Radiometric Calibration ◽  
Practical Utilization ◽  
Vicarious Calibration ◽  
Spatial Uniformity ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Spectral Imager

Pseudo-invariant calibration sites (PICS) have been used for the radiometric calibration and stability monitoring of satellite optical sensors. Several stable PICS, such as those in the Sahara Desert in North Africa, were selected for the vicarious calibration of earth remote sensing satellites. However, the selection procedure of PICSs in the whole of Northwest China has not been fully explored before. This paper presents a novel technique for selecting PICS in Northwest China by combined using the coefficient of variation (CV) and the iteratively reweighted multivariate alteration detection (IR-MAD) technique. IR-MAD, which calculates the differences between two multispectral N-band images from the same scene acquired at different times, is used to identify no-change pixels (NCPs) of the scene through one image pair. The NCPs from IR-MAD using the long-term data of FY-3 visible infrared radiometer (VIRR) and aqua Moderate Resolution Imaging Spectroradiometer (MODIS) were aggregated into the contiguously stable sites. The traditional spatial uniformity and temporal stability from MODIS surface products were used to select the potential PICS. By combining the results of both methods, over thirty PICSs with a wider brightness range of the scene types were selected. To confirm and characterize these PICSs over Northwest China, Landsat operational land imager (OLI) high-spatial-resolution images were used to check the spatial uniformity of the selected site to determine the specific location and the size of these sites. Additionally, the surface spectral reflectance and bidirectional reflectance distribution function (BRDF) were obtained from the field campaign at Chaidamu Basin, 2018. To demonstrate the practical utilization and usability of these PICSs, they were employed in the multi-site top of atmosphere (TOA) reflectance simulation to validate the operational calibration performance of Aqua/MODIS and FY-3D/MERSI-II (Medium Resolution Spectral Imager II). The simulation results showed good consistency compared with the observations from both MODIS and MERSI-II, with a relative bias and root mean square error (RMSE) of <5% and <0.05%, respectively. These sites provide prospects for multi-site vicarious calibrations of solar reflective bands, which may help to evaluate or characterize instrumental nonlinear responses using a wider signal dynamic from the sites in different seasons.

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

&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites&amp;#8217; 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 10.5-11.5&amp;#181;m channel was better than 0.75K (@300K, K=1) and for 11.5-12.5&amp;#181;m channel was better than 0.85K (@300K, K=1).&lt;/p&gt;

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.

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