A Dataset Conjunction Locator Service for the Virtual ITM Observatory and Other VxOs

One of the great time-saving features of Virtual Observatories is the ability to have a single search find products from many different sites at one time. High fidelity search tools allow the user to triage the vast data holdings down to a smaller set of particular interest. The Virtual ITM Observatory (VITMO) provides many methods by which the user can search for and select data of interest including restricting selections based on geophysical conditions (solar wind speed, Kp, etc) as well as finding those datasets that overlap in time and/or space. We are developing a series of light weight web services for use by the Virtual ITM Observatory (VITMO - http://vitmo.jhuapl.edu ) and other VxOs that allows the overlap between multiple satellite data sets to be determined, allowing the VxO to supply both sets of overlapping data products. These web services will also allow "near misses", where products that are only close in time and/or geographical overlap to be optionally selected by the user based on criteria that the user provides. We will provide a generalized set of services that will initially support coincidences between the SABER, TIDI, and GUVI instruments on the TIMED satellite, the SOFIE and CIPS instruments on the AIM satellite, the SUSSI instruments on DMSP F16, F17, and F18, as well as C/NOFS and COSMIC satellites. These services are being built using the Navigation and Ancillary Information Facility (NAIF) SPICE toolkit (http://naif.jpl.nasa.gov/naif/index.html) allowing them to be extended to support any Earth orbiting satellite with the addition of the appropriate SPICE kernels or two-line element sets (TLE). An instrument kernel (IK) file will be used to describe the observational geometry of the instrument (e.g., Field-of-view size, shape, and orientation). This services will allow the non-specialist user of VITMO to select data that they were previously unable to locate, opening up analysis opportunities beyond the instrument teams and making it much easier for future students who come into the field.