NOVELTY - The method comprises measuring (200) the chemical composition of a gas within a gas collection and transmission infrastructure with optical sensors, measuring (202) other physical properties associated with the natural gas within the gas collection and transmission infrastructure, communicatively coupling (204) the optical sensors to a data gathering location, reporting (206) the chemical composition of the gas and the other physical properties associated with the gas to the data gathering location, and determining (208) the chemical composition in real time.    USE - The method is useful for determining and reporting a chemical composition of a gas such as liquefied natural gas and steam for scheduling maintenance within a gas collection infrastructure and for pricing bulk quantities of gas within a gas collection and transmission infrastructure (all claimed).    ADVANTAGE - The method is capable of rapidly, accurately and properly determining the chemical composition of the gas high quality, energy content, improved compressibility, specific gravity and moisture content, reduces the contamination such as hydrogen sulfide, carbon dioxide, water and nitrogen from the natural gas, and allows natural gas to be priced using real time chemical compositions associated with bulk quantities of the gas within the gas collection and transmission infrastructure.    DETAILED DESCRIPTION - The method comprises measuring (200) the chemical composition of a gas within a gas collection and transmission infrastructure with optical sensors, measuring (202) other physical properties associated with the natural gas within the gas collection and transmission infrastructure, communicatively coupling (204) the optical sensors to a data gathering location, reporting (206) the chemical composition of the gas and the other physical properties associated with the gas to the data gathering location, and determining (208) the chemical composition in real time associated with bulk quantities of natural gas within the gas collection and transmission infrastructure. The optical sensors perform spectrographic analysis in near infrared, and comprise an optical cell coupled to the gas collection and transmission infrastructure. The gas is priced using real time chemical compositions associated with bulk quantities of natural gas. A downstream user reconfigures manufacturing processes based on the real time chemical compositions associated with bulk quantities of natural gas. The gas collection and transmission infrastructure are based on the real time chemical compositions associated with bulk quantities of gas. The presence of hydrogen sulfide within the natural gas is determined with the optical sensors. An overall quality of the natural gas is monitored to insure contractual compliance between a buyer and a seller. A natural gas producing reservoir is characterized based on the historical output of the optical sensors to determine production and drilling schedules in an effort to maximize an economic value of the gas producing reservoir, and is valued based on a historical output of the optical sensors. INDEPENDENT CLAIMS are included for:    (1) a method to determine a gas processing configuration;    (2) a chemical composition analyzer to optically determine and report the chemical composition of a gas within a gas collection and transmission infrastructure;    (3) a method to schedule maintenance within a gas collection infrastructure; and    (4) a method to price bulk quantities of gas within a gas collection and transmission infrastructure.    DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of a method for determining and reporting a chemical composition of a gas.    Measuring a chemical composition of a gas (200)    Measuring other physical properties associated with the natural gas (202)    Coupling the optical sensors to a data gathering location (204)    Reporting the chemical composition of the gas and the other physical properties (206)    Determining the chemical composition in real time. (208)