Introducing the NAVCAM image browser
6 March 2015
The first set of images from Rosetta's NAVCAM has been made available to all users via ESA’s Planetary Science Archive (PSA). This first batch of image data covers the period leading up to 2 July 2014, prior to Rosetta's arrival at comet 67P/C-G. Further releases of image data will be made in blocks on a monthly basis henceforth, with the near-term aim to catch-up so that NAVCAM data will be publicly released six months after they are taken.
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| Screenshot of the new Planetary Science archive interface. Credit: ESA |
In addition to the usual Planetary Science Archive interface, the archive team at ESAC in Spain has also implemented a new tool – hosted at imagearchives.esac.esa.int – to enable rapid browsing of the available NAVCAM image data. Standard pipeline processed images can be viewed in a pipeline-processed PNG format in the browser, and the user will then be able to download the original unprocessed data sets for the chosen images, in FITS and PDS formats, including the full header (metadata) information.
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| Screenshot of the new Planetary Science archive interface. Credit: ESA |
These NAVCAM data are fully and freely public, and are geared towards the scientific community or for those with an interest in data and image processing.
For the general public, however, we recommend looking out for the fully-processed images that we regularly publish via the following outreach channels:
-The image collections available on our Science & Technology pages: “67P by Rosetta” (publicly released OSIRIS and NAVCAM images) and “67P - NAVCAM” (NAVCAM images)
-ESA main Portal image gallery (search for Rosetta for all images linked to the Rosetta mission and that have been released e.g. via news stories/press releases)
-The Rosetta blog, as part of our regular CometWatch series
-Our Rosetta social media platforms on Facebook, Twitter, and Instagram and wider ESA social media, including Flickr and Google+
For more information about the new image browser and associated data releases, please check the Q&A below:
Who is the viewer for?
If you enjoy seeing new images of the comet but are happy with the fully-processed images released 2–3 times a week in the Rosetta CometWatch blog posts, then simply visit the blog, and/or browse the image galleries highlighted above. But if you would like access to all images in the NAVCAM image archive along with context information for each, then the NAVCAM browser is for you. For scientists wishing to process the raw data and perform detailed analysis, they can also access the PSA to download the full data sets contained there.
What format are the images in the NAVCAM browser?
The standard output image is a PNG file, but links are also provided to download the images in FITS and PDS format. Information about NAVCAM and the properties of the images are available in the browser (here).
Have the images been processed in any way?
For the PNG files, some basic cleaning scripts have been applied to remove so-called double pixel pairs – dark/bright pixels beside one another. If you are interested to read more, please refer to the processing information contained in the NAVCAM image browser (here). The FITS and PDS files are in raw and unprocessed form.
What reference data do I see with the images?
With each image, you will also find information including the date/time the image was taken (year-month-day and hour:minutes:seconds format in UTC, on-board spacecraft time); the distance to the centre of the comet (km); and the exposure time of the image (seconds). All metadata produced is available in the label file provided with each image and detailed information can be found in the PSA in the usual way.
How are the images organised?
The images are contained in folders linked to the planning periods of the Rosetta scheduled activities. These are known as MTP’s (Medium Term Plans), where one MTP typically corresponds to approximately four weeks of Rosetta scheduled activities during “normal business” (this varies if special events are scheduled, such as during the lander separation activities). For example, images from MTP001 and MTP002 are contained in the “Prelanding Commissioning” folder and they cover the period after wake-up in January 2014 and for the instrument commissioning phase until early May, while MTP003 and 004 are for four-week periods and include the first detection of the comet.
You can also search for images via keyword, date, most visited, date added, and so on.
Can I download and share the images myself?
Yes, just like the images we publish in the regular CometWatch series, all NAVCAM images accessible via the new viewer are released under the so-called CC BY-SA 3.0 IGO licence – the “attribution share-alike” creative commons licence. For more info, see our blog post: Rosetta NAVCAM images now available under a creative commons licence.
How often will the image viewer be updated?
In the first release (today, 6 March), images are being released from the period following Rosetta’s wake-up in January 2014 until 2 July 2014 (300 images). Note that these are from the approach phase to Comet 67P/C-G, and so do not feature any close up images – these will come in the next releases. While the future releases will follow a monthly release schedule, the near-term aim is to catch-up to the point where NAVCAM data will be publicly released approximately six months after they are taken. We will also continue to bring you our regular CometWatch feature to highlight more recent images.
How will I know when there’s a new release of images in the viewer?
The image browser has a page to enable RSS feeds (here) providing notification when new images are added to the archive image browser. We will also include a reminder here on the blog as part of the one of the regular CometWatch releases of that week.
When will OSIRIS images and other data from the mission be available?
The new image viewer is essentially a ‘beta release’ and is currently exclusively for NAVCAM images. However, it is planned to extend it to include data from other Rosetta instruments: the release of scientific data from these instruments covering the period January–November 2014 is foreseen starting in May 2015, depending on the instrument.
Don’t forget that data from many instruments (including OSIRIS) are already available on PSA from the cruise phase of the mission, prior to hibernation entry in July 2011. NAVCAM images from the cruise phase will also be added to the browser in due course.
What about access to data from other missions?
In the future, the goal is for this tool to be extended to allow wider access to image data from other ESA space science missions whose data are held in the PSA or other archives.
Your feedback is welcome on the new browser to help the archive team improve it in future versions – please posts comments on the blog post here.