OPUS Update for April 2024 - PDS4 Support, New Ring Geometry Metadata, Display of Units

It has been awhile! For the past year and a half, we have been busy improving OPUS under the covers, and are finally ready to show off what we've done: Support for PDS4, including our first PDS4 bundle; new ring geometry metadata fields; easy selection of display units; and various other smaller improvements and fixes.

PDS4 Support

OPUS now supports PDS4! Our goal is to make PDS3 and PDS4 data sets indistinguishable to most users. Nevertheless, there are a few PDS4-specific changes:

• Everywhere OPUS used to say "Volume" it now says "Bundle/Volume". As we want to focus on PDS4 going forward, the API slug volumeid has been renamed to bundleid, although volumeid is still available for backwards compatibility.
  
• The PDS Constraints search category has renamed Data Set ID and Product ID to indicate that they are PDS3-specific fields, and added a new field Primary Product LID for PDS4 data. Since a single OPUS observation can contain many downloadable products, all of which have their own LID, we choose a "primary product" to represent the observation and allow searching on its LID. This is the same product whose filename is given in the Primary File Spec field. The field Bundle/Volume ID contains the volume name of PDS3 data and the bundle name of PDS4 data. 
• We have standardized the names of ground-based telescopes, and their abbreviations in OPUS IDs, to conform more closely to PDS4 naming standards. This has affected the PDS3 EBROCC_0001 volume in a non-backwards-compatible manner.
• We likewise have standardized the names of the DSN dishes, which are now appropriately called "DSS nnn".

Along with these PDS4 changes, we are providing our first set of PDS4 bundles - the uranus_occs_earthbased occultations of Uranus and its rings from ground-based telescopes. As with all OPUS data, we provide thumbnail diagrams to make visual searching easy, and permit selective downloading of all PDS4 products associated with each observation.

Ring Geometry Metadata Fields

Since the beginning, OPUS has provided ring longitudes referenced to the First Point of Aries, otherwise known as Right Ascension = 0. This is contrary to what many ring researchers use, which is longitudes referenced to the Ascending Node of the ring plane of the given planet at a specific epoch. We have now implemented both versions for all longitude fields, and named them explicitly to avoid further confusion. For now, the Ascending Node longitudes are computed from the RA=0 longitudes for non-occultation data sets, and the RA=0 longitudes are computed from the Ascending Node longitudes for occultation data sets, based on an approximate constant offset with an epoch during the Voyager era. As most planets precess very slowly, any errors in the conversion should be negligible. In the future, as we import fresh metadata, these values will be computed precisely.

Surface Geometry Metadata Fields

Previously, many surface geometry metadata fields that referred to values that were specific to a body's location, such as Sub-Solar Planetocentric Latitude, Sub-Observer Planetographic Latitude, or Body Center Resolution, contained only a single value in the OPUS database for each observation. However, as it is possible for these values to change over long observation periods, the database now contains minimum and maximums for these fields, as was already done for all other surface and ring geometry fields. For now, no data sets take advantage of this change, but you may notice the new min/max fields when viewing the metadata for an observation.

Selection of Display Units

Back in May 2021, we implemented units on the Search tab. Now it is also possible to select what units you want to be used when displaying metadata. This can be done from the Select Metadata dialog, and the units will be used wherever the select metadata fields are displayed (such as on the Detail tab or in slideshow mode).

Miscellaneous Changes

A few other miscellaneous changes have been made to the data:

• The Ring Geometry Constrains field Observed Resolution is now always N/A for occultations; please use Projected Radial Resolution.
• Documentation related to each mission, instrument, and data set has been added to the available download options for some data sets.
• The RMS Node-generated profile_index files for occultation data sets have been removed from the available download options, as these files are deprecated.
• The Wavelength of Cassini VIMS occultations has been corrected to be the narrowband range actually used by the occultation instead of the full available range of the instrument.

As always, we enthusiastically solicit questions and feedback from our users. And don't forget to follow us on Twitter (now X) and Mastodon for real-time updates. You can also join our low-volume announcements mailing list.

OPUS Update for August 2022 - Detail Tab, Category Hints, Download Old Versions, Metadata Units

Since our last update in March, we have been busy adding a number of behind-the-scenes features that will enable future development. But we've also added a few features that are useable right now! These include showing all of the available browse and preview products on the Detail tab, summarizing the number of results in collapsed categories on the Search tab, being able to download old product versions from the Cart tab, and retrieving metadata in various units through the API.

Multiple Browse and Preview Products

Many observations have multiple browse or preview products available. For example, Cassini CIRS observations often have body surface footprints and ring footprints. Occultations can have elevation angle graphs, ring footprints from different perspectives, and the occultation profile itself. Now when you view an observation on the Detail tab, you have the ability to scroll through all available browse and preview images. Just click on one of the arrows or the dots under the image, or use your keyboard's arrow keys, to change which image you are viewing.

Summarizing Category Results

OPUS has green "hinting" numbers that show you the number of results that you will get if you click on a checkbox during a search. However, previously when a category (like "Saturn" or "Uranus") was closed, you couldn't see whether there were any valid results under that category. OPUS now gives you the total number of results next to the category name, as well as the number of results for each checkbox as before.

Downloading Old Product Types

Some PDS products have multiple versions. For example, an updated calibration pipeline may have caused the release of new calibrated products. OPUS has always allowed you to download old versions one at a time from the Detail tab:

but now old versions are also available for download directly from your Cart, allowing the download of groups of old products at once. Because most users only want the most recent product versions, old products are not shown by default, and clicking "Select all current version product types" will not select the old versions.

Support for old versions has also been added to the /api/download and /api/files.json API endpoints. See the API Guide for details.

Metadata Units in the API

It is now possible to specify the desired units of metadata in the API. For example, if you want to get an observation's starting time as a Julian Date instead of the default YMDhms, you can ask for:

https://opus.pds-rings.seti.org/opus/api/metadata/co-iss-w1866600688.json?cols=time1:jd

See the API Guide for detalis.

As always, we solicit your comments, feedback, and questions! If you haven't already, please join the opus-users mailing list. We promise not to spam you, but just to let you know when cool new features have been released.

https://list.seti.org/cgi-bin/mailman/listinfo/opus-users

OPUS Update for February 2022 - New Galileo and New Horizons Volumes, East Longitude

This month we added two new datasets to OPUS: Galileo SSI volumes pre-Jupiter, and New Horizons volumes post-Pluto. We also fixed a few bugs and added a new set of "East Longitude" fields.

Galileo SSI

OPUS now contains 10,624 new observations taken by Galileo SSI from PDS volumes GO_0002 through GO_0016. These observations include fly-bys of Venus, Earth, and the Moon.

The Earth as seen by Galileo, December 11, 1990

New Horizons

OPUS also now contains 10,224 new observations taken by New Horizons after its encounter with Pluto, including its encounter with Arrokoth.

Arrokoth as seen by New Horizons, January 1, 2019

New East Longitude Fields

In Surface Geometry Constraints, the various longitude fields have been divided into two sections: west and east. The east fields are new, and have been added to make searching easier. The IAU longitude fields are equal to 360 minute the corresponding west field. The WRT fields (which range from -180 to +180) are the negative of the corresponding west field.

Other Changes

We also made a number of small bug fixes to the metadata, including:

• The COCIRS_0xxx and COCIRS_1xxx volumes now have values for wavenumber resolution. In addition, the Cassini Observation Name has been corrected, which also changes the values of Activity Name, Cassini Target Name, and Saturn Orbit Number.
• The maximum wavelength for Cassini UVIS EUV and FUV observations is now correct.
• There are now preview diagrams for the Cassini UVIS occultations volume COUVIS_8001.

As always, we solicit your comments, feedback, and questions!

OPUS Update for November 2021 - Voyager occultations and CIRS map cubes

This month we have added two new datasets to OPUS: Occultation and reflectance profiles from Voyager, and CIRS map cubes.

Voyager Profiles

OPUS now includes occultation profiles of the rings of Saturn, Neptune, and Uranus taken by the Voyager 1 RSS and UVS and the Voyager 2 RSS, UVS, and PPS instruments. It also includes reflectance profiles of Saturn's rings taken by both Voyager spacecraft. The latter are available using the new "Reflectance Profile" Observation Type. To support this new observation type, the Occultation Constraints sub-menu has been renamed to Occultation/Reflectance Profile Constraints. No preview images are currently available for these observations, so we recommend using the Table View to view the metadata.

Cassini CIRS Map Cubes

OPUS also now includes the CIRS Map Cubes from volumes COCIRS_0xxx and COCIRS_1xxx. These observations are available using the "Spectral Cube" Observation Type. Spectral cubes are available for Saturn, Saturn's moons, and Saturn's rings.

Changed Default Search Fields

In addition, we have changed the default search fields to better represent the types of searches our users normally perform. The default fields are now Instrument Name, Observation Type, and Intended Target Name.

As always, we hope you and your loved ones stay safe this holiday season, and we activity solicit your feedback, comments, and questions on OPUS.

OPUS Update for October 2021 - Resizeable slideshow, share details

It's time for another multi-month update! This time we have a few small features that should make your life easier.

Resizing the Slideshow View

The slideshow view can now be resized, including being minimized or maximized. This allows you to view the metadata details of observations while still being able to get a good view of the entire thumbnail gallery. The observation you are currently viewing is marked with a large pair of binoculars. Once you have exited the slideshow view, the last observation you viewed is marked with a small pair of binoculars in the top-left corner.

Showing Which Observation is Featured on the Detail Tab

Do you ever lose track of which observation is currently showing on the Detail tab? There are now two indications to help you:

• The thumbnail for the observation will have the word "DETAIL" in the upper-right corner
• A small version of the thumbnail is shown in the header next to the word Detail; hovering over this thumbnail will show the observation's OPUS ID

Creating a Short URL for the Detail Tab

Have you ever wanted to share a single observation with someone? You can do this using the full OPUS URL, but it can be very long. To help with this, there is now a "SHARE" button on the Detail tab that copies to the clipboard a short URL of the form:

https://opus.pds-rings.seti.org/opus/#/view=detail&detail=co-iss-w1665997909

This URL can be saved for future use, or sent to another researcher, mailing list, or even tweeted to give an easy way to see the details about the given observation, without including information about the search or selected metadata fields.

Help for Preview Images

Did you ever wonder what the design and coloring of the thumbnails for Cassini CIRS, UVIS, and VIMS mean? The documents that describe these are now available directly from the Help menu.

As always we actively solicit your questions, feedback, and comments. Feel free to send a DM on Twitter or use the Feedback tab found on the right side of the OPUS screen. No question or comment is too small. We wish you and yours a happy holiday season.

OPUS Update for May 2021 - New units and formats, selection of download format

It's time for another two-month update! This time we are pleased to announce a number of small features designed to increase the flexibility of how you use OPUS.

New Units and Formats

We have added new units and display formats for longitude- and latitude-like fields (including right ascension, declination, and solar hour angles). Depends on the field, you can now select:

• Decimal degrees
• DMS (degree-minute-second)
• Decimal hours
• HMS (hour-minute-second)
• Decimal radians

DMS or HMS can be entered in various free-form formats like 12d 53' 6.23'' or 12h 30m 0s. The format is automatically detected, so even if you have selected "decimal degrees" as the unit, you can still enter the value in DMS or HMS format. If you enter a value in degrees while DMS or HMS is selected, the value is automatically converted, giving a very convenient way to convert degrees to DMS and hours to HMS (or vice versa) even if you don't plan to use OPUS to do a search! We also support a variety of Unicode characters for the degrees symbol, ', and '', which allows convenient copy-paste from web pages, including Wikipedia.

We have also added new formats to date-time fields. Dates may be entered and/or displayed as:

• YMDhms - Year, month, day, hour, minute, second (1981-07-19T19:30:22.520)
• YDhms - Year, day of year, hour, minute, second (1981-200T19:30:22.520)
• Julian Date - The number of elapsed days since noon on Monday, January 1, 4713 BCE. Each period from one noon to the next counts as one day, regardless of whether that day contains leap seconds. As a result, some days are longer than others. (JD2444805.31276065)
• Julian Ephemeris Date - Similar to SPICE Ephemeris Time but in units of days instead of seconds (JED2444805.31336462)
• Modified Julian Date - Julian Date minus 2400000.5 (MJD44804.81276065)
• Modified Julian Ephemeris Date - JED minus 2400000.5 (MJED44804.81336462)
• SPICE Ephemeris Time - The time unit used by the SPICE toolkit, defined as the number of elapsed seconds since noon on January 1, 2000, and adjusted for relativistic effects that cause a clock on the Earth to vary in speed relative to one at the solar system barycenter. (-582308925.296)

Selection of Download Format

We have added a couple of options to the Download Options on the Cart tab. It is now possible to select the type of archive file (.zip, .tar, or .tgz) as well as the archive's internal file structure. The default is "flat", which is the previous behavior. With "flat" selected, all selected data products are placed in the root level of the archive file. There is a minor change though: if two different files have the same base filename, such that placing them in the root would cause a duplicate filename, they are now added to the archive using their full directory path as stored in the RMS archive. If "flat" is unselected, then all data products in the archive are stored using their full directory paths, completely mirroring the structure of the RMS archive.

Adding or Removing an Observation from the Cart on the Detail Tab

We have added the ability to add or remove an observation from the cart on the Detail tab. In addition, the header of the Detail tab is now frozen so that it is always visible.

Minor Metadata Changes

We have made a number of minor changes to the metadata and the available file products. These include fixing a bug with the wavelength of HST STIS observations and adding superseded-processing products to the available Galileo SSI download products. These changes are unlikely to be visible to most users.

As always we actively solicit your questions, feedback, and comments. Feel free to send a DM on Twitter or use the Feedback tab found on the right side of the OPUS screen, or start a chat with one of our team members. No question or comment is too small. We hope you and your family are staying safe and healthy as we all look forward to returning to a more normal life soon.

OPUS Update for March 2021 - Chat, New Data, Metadata Improvements

It's been awhile since we had an update, but we've been working hard behind the scenes on improvements. This month we're pleased to announce three basic changes: new chat functionality, new data, and improved metadata.

Chat

We really, really want to hear from you! We want to make sure you have every opportunity to ask questions and provide feedback. As such we've added a new "Chat" function. If one of the Ring-Moon Systems Node OPUS experts is available to help, you will see a Chat icon in the lower-right corner of the Search and Detail tabs. Entering your question or comment here will connect you directly to one of our team members for live help. We look forward to hearing from you.

Data

Although there are no new missions or instruments at the moment, we did add or improve the following data sets:

• The COISS_2xxx volumes (Cassini at Saturn) have a complete set of new calibrated data (using CISSCAL 4.0)
• COUVIS_0xxx volumes have been updated to the latest release (version 3) and have new, improved preview images
• COUVIS_8xxx (occultation) volumes have been updated to the latest release (version 3)
• All occultation volumes now have preview images, and most have browse diagrams detailing occultation geometry

Metadata

There have been many improvements to the RMS-generated metadata as well as a few metadata-related bugs fixed in OPUS. Metadata changes are described in new AAREADME.TXT files present in each metadata directory in the archive. Changes include:

• For all relevant volumes, the body inventory table has been renamed from inventory.tab to inventory.csv to better represent its format
• Product Creation Time has been added for most instruments
• The Observation Type of Hubble observations has been standardized. Image is data with two spatial dimensions with each pixel containing an intensity value. Spectrum is data with zero or one spatial dimension with each pixel containing a complete spectrum. Spectral Image is data with two spatial dimensions with each pixel containing partial spectral information (usually the result of a prism or grism). Spectral Cube is data with two spatial dimensions with each pixel containing a complete spectrum. In addition, the Wavelength, Wavelength Resolution, and Spectrum Size fields have been updated to be consistent across all Hubble instruments.
• CORSS_8xxx:
• Several occultations that were missing from OPUS have been added
• The format of OPUS IDs has been changed to include the "rev" number
• The Wavelength was stored with the wrong unit and is now correct
• COUVIS_0xxx: Data Set IDs have been updated
• COUVIS_8xxx: Wavelength was stored with the wrong unit and is now correct
• COVIMS_0xxx:
• Several observations from COVIMS_0012 that were missing from OPUS have been added
• "Packed" versions of observations have been removed when the "unpacked" versions are available
• Many additional data product types are available for download in OPUS
• COCIRS - Observation Metadata (ISPM)
• CORSS - Documentation and Browse Products
• EBROCC - Geometry Table, Preview Plot, Geometry Diagram, Source Data, and Browse Products
• HST - HST Files Associations Index
• VGISS - Extra Preview
• GOSSI version 1 data products are no longer available for download through OPUS
• HST: Data Set IDs have been updated

As always we actively solicit your questions, feedback, and comments. Feel free to send a DM on Twitter or use the Feedback tab found on the right side of the OPUS screen, or start a chat with one of our team members. No question or comment is too small. We hope you and your family are staying safe and healthy.

OPUS Update for September 2020 - Linked Search Fields

This month we bring you two small changes to improve the user experience: a new way to remove search fields, and linked search fields so they are easier to find.

Removing Search Fields

In the past, the only way to remove a search field on the Search tab was to click the "X" in the upper right corner. This functionality is still present, but now you can also remove a search field by clicking on the search field name on the left side of the screen as well. This mirrors the existing behavior in the Select Metadata dialog. Because it's easier to do this by accident, if you have placed any constraints on the search term you will be asked to confirm before the field is removed.

Linked Search Fields

In some cases, it may be difficult to find the metadata fields that you are interested in because they are contained in a different category. For example, when looking at occultations you are likely interested in ring radius and ring opening angle, but these fields are in the Ring Geometry Constraints category. Likewise when looking at images, you may be interested in the exposure duration, but this field is in the Image Constraints category. To make things easier for the user, we have placed "links" to some of these common fields in the places where people may expect to see them. Selecting a field in the "linked" location is exactly the same as selecting it in its native location, and both locations will be highlighted.

As always we actively solicit your questions, feedback, and comments. Feel free to send a DM on Twitter or use the Feedback tab found on the right side of the OPUS screen. No question or comment is too small. We hope you and your family are staying safe and healthy.

OPUS Update for August 2020 - Specifying Metadata Fields in Table View, Index Files, STIS Fields

 This month we have a new feature in Table View and a few updates to the available metadata.

Selecting Metadata Fields (Part 2)

Last month we added the ability to select metadata fields while in the Slideshow View. This month we added the ability to do the same thing while in the Table View. To add or remove a field, simply hover your mouse over the table header. A small toolbar will appear below the field you've selected. Clicking on the trashcan icon in the middle will remove the field from the selected metadata fields. Clicking on the + on the left or right of the toolbar will allow you to add a new field before or after the selected field.

Index Files as Downloadable Products

We have added our own PDS3 metadata index files ("RMS Node Augmented Index", "Supplemental Index", and "Profile Index") as downloadable products. As these are probably not needed for the average user, they are not included by default when downloading the cart contents. At the same time, we made some other product types (such as small preview images) not download by default as well. You can always explicitly select these product types if you want to include them in your download. Note there is only one set of index files for a given observation regardless the number of data versions available.

STIS Metadata Fields

We have added a new field for HST STIS: STIS Proposed Aperture Type. We have also corrected some errors in the normal Aperture Type for STIS.

As always, we thank you for using OPUS and appreciate your feedback, comments, or questions.

OPUS Update for July 2020 - Specifying Metadata Fields, Tutorial Videos, Microsoft Edge

We skipped the update for June so that we could bring you an extra-special combined update for July.

Selecting Metadata Fields

The existing Select Metadata feature (available on the Browse and Cart tabs) allows you to choose which metadata fields are displayed:

• In the Table View
• In the Slideshow View (when you click on a thumbnail)
• On the Detail tab

as well as which fields are saved in downloaded CSV files. Similar functionality is now available directly in the Slideshow View. To get to the slideshow, simply click on any thumbnail in the Gallery View or any table row in the Table View. From this view, you can see a larger preview image, view the values for selected metadata fields, add observations to (or remove observations from) the cart, access a variety of features using the mini-menu in the lower right, and move to the next or previous image in your search results using the arrows in the window or the arrow keys on your keyboard.

To modify the set of metadata fields available in the Slideshow View, simply click on "Edit" at the top:

Once in "Edit" mode, you will be able to drag fields to reorder them, delete fields by clicking on the trashcan icon, or add new fields by clicking on the "+".

When finished modifying the list, click on "Done" at the top.

New Tutorial Videos

The Ring-Moon Systems Node now has a YouTube channel. We currently have two OPUS tutorials that were given at the recent OpenPlanetary virtual conference, one on how to use OPUS in the browser, and one on using the OPUS public API. The videos are also linked from the OPUS Help menu.

Support for Microsoft Edge

Microsoft has released a new version of their Edge browser, based on Chrome, which has the necessary features to support OPUS. As a result, we now consider it a supported browser.

As always, we thank you for using OPUS and appreciate your feedback, comments, or questions.