These are preliminary data from the Atmospheric Tomography (ATom) mission that have been made available to facilitate scientific assessment. These data have not completed post-mission checks for Quality Assurance/Quality Control (QA/QC) and final calibrations. By downloading these data, the user agrees that these preliminary data may never be used or published in archival media such as journals or meeting proceedings. Archival publications must use only public release data that have completed QA/QC. Public release of ATom data is anticipated within 12 months after each phase of the ATom project.