Saturday, November 17, 2018

Recent updates to OPUS (new OPUS ID format!)

  • There is now a link for Questions and Feedback in the top menu bar. Please use it!
  • The format of the OPUS ID (used to uniquely identify observations) has changed. The previous format was incompatible with the upcoming migration to PDS4. The new OPUS ID format should stay consistent for the foreseeable future. The old OPUS ID format is no longer supported. Some examples of the change:
        Old: COISS_1001-1294561143_1295221348-W1294561143_1
        New: co-iss-w129456114
        Old: NHLALO_x001-20060224_000310-lor_0003103486_0x630
        New: nh-lorri-lor_0003103486
  • We have removed the short-lived search fields Spatial Sampling, Wavelength Sampling, and Time Sampling and returned to a simpler way of describing observations called Observation Type. Current choices include:
    • Image (a 2-D array of intensity values)
    • Spectrum (a 1-D array of intensity vs. wavelength)
    • Spectral Image (similar to Image, but a grating or prism has been used to spread out the spectrum along one of the axes)
    • Spectral Cube (a 3-D array, similar to an Image but with each pixel value containing an entire spectrum)
    • Time Series (a 1-D array of intensity or optical depth vs. time, such as for an occultation)
    • Spectral Time Series (similar to Time Series, but containing a spectrum for each time step)
  • The Primary File Spec for Galileo SSI observations has been changed. The original format, which looked like "GO_0017:[J0.OPNAV.C034640]5900R.IMG", was based on an ancient filesystem constraint that required the actual filename to be split across multiple directories because it was too long. This resulted in the final filename, such as "5900R.IMG", being non-unique. We have changed the format to have a more modern, non-restricted format such as "GO_0017/J0/OPNAV/C0346405900R.IMG", where each filename is now unique.
  • When downloading observations that have been selected, the available products are now categorized and sorted by their product type, such as "Metadata Products", "Browse Products", and "Mission-Specific Products".
  • The definition of Planet has been changed for Cassini and New Horizons instruments. Previously, Planet was based on the Intended Target Name, so that an observation of Venus was marked as planet Venus. Now, consistent with other missions and instruments, the Planet field indicates approximately where the spacecraft was when the observation was taken. For most observations, this is a good starting point when looking for images of that particular planet, but if you want to be more specific use the Intended Target Name or Surface Geometry Target Name. The exception to this is the Hubble Space Telescope, which is always around Earth. In this case, the Planet field is still based on the Intended Target Name.
  • The definition of Measurement Quantity for Cassini UVIS has been changed. The choice between Optical Depth and Emission is no longer dependent on the instrument mode, but instead depends on the textual Note included with the observation. Any observation with a Note containing "OCCULTATION" is marked as Measurement Type Optical Depth. All other observations are marked as Emission.
  • We have added descriptive text to help users understand the difference between Intended Target Name and Surface Geometry Target Name.
  • For added clarity, we have renamed some targets:
    • J Rings → Jupiter Rings
    • S Rings → Saturn Rings
    • U Rings → Uranus Rings
    • N Rings → Neptune Rings
    • J Minor Sat Jupiter Minor Satellites
    • Cal Lamps Calibration Lamps
  • It is now possible to right-click on the View Detail link anywhere it appears and open OPUS in a new browser tab or window with the Detail tab selected.
  • The /api/files JSON return has been changed. Previously the product type was identified by a "pretty name" such as "Raw Data". We have changed this to a simple slug-style name such as "coiss-raw" to decouple the user experience from the internal data representation. The precise data products available for each instrument are complicated (it's not as simple as just "raw" or "calibrated" when you look at all the things we currently support or are going to support). We decided to split them out by instrument so that we could give the full information to the user, rather than risk merging data products together that really aren't in the same category. Anything that is truly generic, such as browse images (browse-thumb, browse-small, etc.) or geometry indexes (ring-geometry, moon-geometry) do not have the instrument name in the front. Anything that could be different from instrument to instrument (e.g. coiss-raw, coiss-calibrated, or coiss-thumb [a special COISS-specific browse image - it's not the same thing as browse-thumb]) has the instrument name prepended. If you only want raw images, it should be easy enough to just look for keys ending in "raw", but be aware that some instruments, like Hubble, may have a different concept of what raw means.
  • Several annoying bugs were fixed. It is once again possible to sort in the table view on a field that contains multiple choices. There was a 3-order-of-magnitude error in the Observation Duration for certain instruments. Some HST NICMOS aperture names were listed twice, with only one working. Some observations were being treated as separate when they were really just separate products available for the same observation; fixing this results in a slightly smaller number of search results for some instruments. It is now possible to download all downlink copies of certain Cassini VIMS observations.

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