Table 2.

Comparison of monitoring methods for atmospheric conditions.

Monitoring methods	Principle	Distribution	Advantage	Disadvantage
Monitoring stations	High-Sensitivity Spectroscopic Techniques, Fourier Transform IR Spectroscopy, Fluorescence Spectroscopy Technique, Differential Optical Absorption Spectroscopy, Non-Dispersive Infrared Technology, Photoacoustic Spectrometer Technology (41, 42)	Large Urban and Small Peri-Urban Areas	24-Hour Continuous Online Monitoring and Construction of Heavily Polluted Areas	High Construction and Maintenance costs, Land Use Constraints, Sparse Network, Limited Regional Coverage
Individual monitoring	Scattered Light Principle and Changes in Specific Properties of Sensing Materials in the Presence of Gaseous Species	Randomness	Low-Cost, Portable, Real-Time Monitoring, Targeting Specific Population Groups for Monitoring Placement in Any Region	Short Monitoring Range, Low Sensitivity, Susceptibility to Missing Data, Challenges in Large-Scale Implementation
SRSM	Differential Optical Absorption Spectroscopy; Deep Blue Algorithms, Dark Target Algorithms, Structural Function, Polarization, Ultraviolet, Multiangle Algorithms et.al	Globally	Broad Coverage, Continuous Space-Based Observation, Enabling Real-Time Monitoring, Mapping of Pollution across the Earth’s surface, Extended Lifetime without physical contact with atmospheric pollutants	Meteorological Factors, Encounters Non-Random Missing Regional Data and Exhibits Discontinuities.