A new method for serving observational data, based on a reusable geo-processing workflow (GPW), is proposed in order to meet the requirements of the automatic AutoChem data feed service in the sensor web environment. A service-oriented architecture (SOA) is adopted. The system has three roles: the GPW provider, registry center, and portal. The system has GPW design, deployment, registration, search, and invocation functions. The AutoChem data discovery, processing, and integration GPW is implemented by chaining NASA EOS ClearingHOuse data service system, the George Mason University (GMU) Catalogue Service for the Web, the GMU Web Coverage Service, and a series of preprocessing services wrapped with the Web Processing Service. The reused data feed flows have been tested using data from the NASA Aura Ozone Monitoring Instrument. Test results show that the proposed data feed service can also be used by the NASA Aqua Atmospheric Infrared Sounder and the Aura Microwave Limb Sounder. Its architecture is more flexible, and it performs more automatically than the traditional method.