Assessing Spatial and Temporal Patterns of Observed Ground-level Ozone in China.

Elevated ground-level ozone (O), which is an important aspect of air quality related to public health, has been causing increasing concern. This study investigated the spatiotemporal distribution of ground-level O concentrations in China using a dataset from the Chinese national air quality monitoring network during 2013-2015. This research analyzed the diurnal, monthly and yearly variation of O concentrations in both sparsely and densely populated regions.

[In-Flight Radiometric Calibration for ZY-3 Satellite Multispectral Sensor by Modified Reflectance-Based Method].

Through integrating multi-spectral sensor characteristics of ZY-3 satellite, a modified reflectance-based method is proposed and used to achieve ZY-3 satellite multispectral sensor in-flight radiometric calibration. This method chooses level 1A image as data source and establishes geometric model to get an accurate observation geometric parameters at calibration site according to the information provided in image auxiliary documentation, which can reduce the influences on the calibration accuracy from image resampling and observation geometry errors. We use two-point and multi-points methods to calculate the absolute radiometric calibration coefficients of ZY-3 satellite multispectral sensor based on the large campaign at Dongying city, Shan Dong province.

[Evaluation of four dark object atmospheric correction methods based on ZY-3 CCD data].

The present paper performed the evaluation of four dark-object subtraction(DOS) atmospheric correction methods based on 2012 Inner Mongolia experimental data The authors analyzed the impacts of key parameters of four DOS methods when they were applied to ZY-3 CCD data The results showed that (1) All four DOS methods have significant atmospheric correction effect at band 1, 2 and 3. But as for band 4, the atmospheric correction effect of DOS4 is the best while DOS2 is the worst; both DOS1 and DOS3 has no obvious atmospheric correction effect. (2) The relative error (RE) of DOS1 atmospheric correction method is larger than 10% at four bands; The atmospheric correction effect of DOS2 works the best at band 1(AE (absolute error)=0.

[A review of atmospheric aerosol research by using polarization remote sensing].

In the present paper, aerosol research by using polarization remote sensing in last two decades (1993-2013) was reviewed, including aerosol researches based on POLDER/PARASOL, APS(Aerosol Polarimetry Sensor), Polarized Airborne camera and Ground-based measurements. We emphasize the following three aspects: (1) The retrieval algorithms developed for land and marine aerosol by using POLDER/PARASOL; The validation and application of POLDER/PARASOL AOD, and cross-comparison with AOD of other satellites, such as MODIS AOD. (2) The retrieval algorithms developed for land and marine aerosol by using MICROPOL and RSP/APS.

[Effects of aerosol optical thickness on the optical remote sensing imaging quality].

In recent years, due to changes in atmospheric environment, atmospheric aerosol affection on optical sensor imaging quality is increasingly considered by the load developed departments. Space-based remote sensing system imaging process, atmospheric aerosol makes optical sensor imaging quality deterioration. Atmospheric medium causing image degradation is mainly forward light scattering effect caused by the aerosol turbid medium.

[Influence of measurement errors of radiation in NIR bands on water atmospheric correction].

For standard algorithm of atmospheric correction of water, the ratio of two near-infrared (NIR) channels is selected to determine an aerosol model, and then aerosol radiation at every wavelength is accordingly estimated by extrapolation. The uncertainty of radiation measurement in NIR bands will play important part in the accuracy of water-leaving reflectance. In the present research, erroneous expressions were derived mathematically in order to see the error propagation from NIR bands.

[The research on remote sensing dust aerosol by using split window emissivity].

Dust aerosol can cause the change in the land surface emissivity in split window by radiative forcing (RF). Firstly, the present paper explained from the microscopic point of view the extinction properties of dust aerosols in the 11 and 12 microm channels, and their influence on the land surface emissivity. Secondly, on April 29, 2011, in the northern region of Inner Mongolia a strong sandstorm outbroke, and based on the analysis of the changes in land surface emissivity, this paper proposed a dust identification method by using the variation of emissivity.

[Retrieval of dust fraction of atmospheric aerosols based on spectra characteristics of refractive indices obtained from remote sensing measurements].

Mineral dust is an important chemical component of aerosol, which has a significant impact on the climate and environmental changes. The spectral behavior of aerosol refractive indices at four wavelengths from 440 to 1 020 nm was analyzed based on one year observation obtained from Beijing AERONET site. The real parts of refractive index (n) in each band did not differ greatly, however the imaginary parts (k) showed a significant difference due to the absorption of mineral dust in aerosol.

[The polarization characteristics distribution and correction method of the polarization coupling error in ocean remote sensing system].

With the development of the quantitative researches using ocean color remote sensing data sets, study on reducing the uncertainty of the response of the ocean color remote sensors to the polarization characteristics of the target has been attracting more and more attention recently. Taking MODIS as an example, the polarization distribution in the whole field of view was analyzed. For the atmosphere path radiance and the apparent radiance considering the coupling between ocean surface and atmosphere, the polarization distribution has a strong relation with the imaging geometry.

[Spatial resolution standardization of payload on board of remote sensing satellite based on application requirements].

Remote sensing application requirements are the starting point for design of payload on board earth observation satellite. The generalization, standardization and serialization of payload are the future development trend for payload design. In the present paper, based on the analysis of remote sensing application requirements, the spatial resolution standardization of satellite remote sensing payload, which is the main concerned indicator, was investigated.

[Research on calibration methods of ground-based thermal-infrared radiometer CE312].

The accuracy of the calibration coefficients of the ground-based thermal-infrared radiometer CE312 is one of the most important factors affecting the calibration of the thermal-infrared remote sensors. The theory of two calibration methods which calculate the bandpass radiance and spectral radiance respectively is introduced. The calibration of the CE312-1b is conducted with the blackbody in the laboratory, the accuracy and influence factors of the results are conducted by the MODIS data combined with in situ measurements data at Qinghai Lake in Aug 2010.

[Atmospheric correction method for HJ-1 CCD imagery over waters based on radiative transfer model].

Atmospheric correction is a bottleneck in quantitative application of Chinese satellites HJ-1 data to remote sensing of water color. According to the characteristics of CCD sensors, the present paper made use of air-water coupled radiative transfer model to work out the look-up table (LUT) of atmospheric corrected parameters, and thereafter developed pixel-by-pixel atmospheric correction method over waters accomplishing the water-leaving remote sensing reflectance with accessorial meteorological input. The paper validates the HJ-1 CCD retrievals with MODIS and in-situ results.

[Simulation of polarization SAR imaging of ocean surface].

The polarization synthetic aperture radar (SAR) imaging simulation is of great significance to ocean surface scattering. According to the theory of wind-wave spectrum, rough ocean surface was modeled in the present paper using the two-scale-model. This treatment takes both the large scale and small scale surface into account.

[Simulation and analysis of polarization characteristics for real sea surface sunglint].

The sea surface sunglint is caused by specular reflectance. Water is a kind of dark target with a very low reflectance, so sunglint becomes a big noise in the aerial or aerospace remote sensing images; sunglint is strongly polarized, and can be a natural standard light source for polarized sensor in-flight calibration; sunglint also can be utilized to retrieve gaseous constituents and aerosol properties. For both de-noising and being standard light source, the radiative physic parameters should be calculated accurately.

[Stereoscopic remote sensing used in monitoring Enteromorpha Prolifra disaster in Chinese Yellow Sea].

In the summer 2008, Enteromorpha Prolifra broke out in Yellow Sea and East Sea on a large scale for the first time, and became a marine disaster. The authors constructed a stereoscopic monitoring system which monitored the disaster continuously, dynamically and in real time. The present paper introduced the construction of the stereoscopic monitoring system; through analyzing the spectral characteristics of Enteromorpha Prolifra and ocean water which were acquired in a field experiment, confirmed Enteromorpha Prolifra retrieval models based on multi-platform multi-sensor and multi-spectral remote sensing data, contrasted the different scale monitoring results, and analyzed the evolvement rules with time-series analysis.

[Error analysis of the land surface temperature retrieval using HJ-1B thermal infrared remote sensing data].

Error analysis is playing an important role in the application of the remote sensing data and model. A theoretical analysis of error sensitivities in land surface temperature (LST) retrieval using radiance transfer model (RT) is introduced, which was applied to a new thermal infrared remote sensing data of HJ-1B satellite(IRS4). The modification of the RT model with MODTRAN 4 for IRS4 data is mentioned.

[HJ1A/HSI radiometric calibration and spectrum response function sensitivity analysis].

Hyper spectrum imager (HSI) loaded on HJ-1A satellite is Chinese first spaceborne hyperspectrum sensor. Since the HSI has no spectrum response function of all channels, the usually used calibration method-reflectance based method has been modified, and a new calibration method is proposed, in which the spectrum response function is neglected. Based on the calibration experiment data of Dunhuang in Aug.

[Mid-infrared atmosphere radiation transfer analytic model and remote sensing images simulation].

In order to establish a complete set of simulation system for high-resolution mid-infrared remote sensing and provide a powerful reference for spacecraft design and related works, the importance of atmospheric radiative transfer simulation in this system was considered, and a reasonable and high precision imaging numerical simulation method was expected. Taking into account the characteristics of MIR, including scattering and thermal emission, terms of atmospheric radiative transfer were decomposed based on radiative transfer principle, and images of top of atmosphere (TOA) were simulated according to MODTRAN4 and look-up table method. Besides, adjacency effect caused by atmospheric scattering of neighboring pixels radiation was considered, and an extended point spread function in mid-infrared was coupled with analytical model of atmospheric radiative transfer to simulate TOA images.