The U. S. has been testing radiosonde manufacturer's radiosondes for many decades at test facilities around the country and has developed a number of test techniques for verifying performance. Recent advances in measuring the upper air atmosphere utilizing state-of-the-art referencing technologies and the development of new test techniques within the U.S. are now available for evaluating radiosonde performance to meet the more stringent climate monitoring requirements. Examples of these reference technologies include: NASA's Advanced Temperature Measuring system, LIDARs for measuring the mid-to-upper tropospheric moisture, Snow White, high-precision GPS measurements of height, the Integrated Precipitable Water sensor using GPS techniques, various radiometers, and ground-based surface instrumentation to measure clouds and weather. Each reference technology can play an important role in the Consensus Reference Concept; whereby, data are integrated into information bases from which statistical techniques would be applied to the time-based and pressure/height candidate instrument measurements of say, temperature, moisture variables, cloud bases, and winds as compared to the references in use. The climate and numerical weather prediction communities would assist in the preparation of the set of criteria for performing these inter- and intra-comparisons and determine the minimal variance allowed to be compliant with each reference, i.e., within consensus. This approach will provide these communities a wealth of knowledge in their overall performance, which can be repeated as often as necessary, and can serve as a methodology for allowing each community to come to a consensus on which candidates meet the stated requirements and where more work is needed if they fall short.