A multi-faceted vehicle, Jason is capable of carrying a wide variety of sampling apparatus and of performing many different activities. We provide several documents describing NDSF-maintained data systems and the content that Jason users will receive from them.
Jason’s primary navigation sources are a Doppler velocity log (DVL) in combination with a fiber optic gyroscope (FOG). This information is usually augmented with georeferenced information from an ultra-short baseline (USBL) system. During a dive both histories are displayed in real time and logged by the software package NavG. The two histories are mathematically merged in post- dive processing to yield an improved history.
We recommend bringing to your cruise previously collected navigation and bathymetry, with historical station positions, to increase the efficiency and productivity of your dive time. Jason navigators can guide you in the creation of underlays and waypoints and will incorporate this information into navigation software for use in real time. Prior to your cruise, the NDSF data manager can assist you finding information and processing content.
Jason carries a variety of video and still camera systems, generally described in the Jason User Manual. Please discuss your project’s needs with the Jason team during the pre-cruise process. The Jason control van houses a variety of imagery capture systems that have differing behaviors depending on source and time of development.
Constant Video Recording
Three video cameras (“pilot”, “brow”, and “science”) are captured by duplicate direct-to-hard drive recorders. The video and subtitle files are clipped at a controlled time, usually 15 minutes. The codec is h.264, which provides excellent viewing quality but is unsuitable for production video editing. File volumes are about 2.4GB per hour per camera. The processing of these clips requires about 15 minutes per hour of dive time. Video and subtitle files are merged in post-processing to yield a video with overlays, playable using software such as vlc.
Important activities of the dive can optionally be captured from the watchstander’s choice of high definition (1080i) science, pilot, brow, or ultra definition (2160p) still camera streams to an editable HD clip. These clips are compressed using the Apple ProRes422 family of codecs (2.7GB/3 minutes for high definition, 15GB/3 minutes ultra definition) and contain embedded time code. The resulting file is a .mov file type, playable by QuickTime and editable using NLE software such as Final Cut.
Several sources of still images from Jason cameras are now available.
- Simultaneous still grabbed images from two of the video streams from the science, pilot, or brow, or still image cameras, as selected by science watchstanders. Aside from the still image camera each of these cameras is an Insite mini-Zeus, which produces a 1080i video stream. The system produces color RGB JPG images at 1920x1080 x 8 bits of quantization.
- Standard still camera. Sulis 4k (new March 2018), which produces 5968x3352 images in jpeg
- Photo survey
a. A machine vision camera & dscam software that is alternatively used for periodic (~10 seconds) downlooking shots, from which Bayer-coded TIFFs, color TIFFS, and color jpegs are produced. By pre-cruise
b. Still images from the various Insite mini-Zeus cameras (SciCam, BrowCam, PilotCam), with the control set to a periodic sampling period. The uncertainties of controlling the pan and tilt mounts and the camera zooms may demand complex post-processing, but this offers an alternative when a downlooking configuration cannot be supported.
Jason lighting has recently been improved, but some limitations on camera configurations exist. In particular, downlooking captures require use of strobes that can be flashed no more quickly than every ~10 seconds. Please be sure to discuss photographic requirements in the pre-cruise process.
All image filenames denote image capture time. A post-processed product merges vehicle navigation to image filename at the time the image was captured (.ppfx file).
Logging of Events
The Jason Virtual Van captures event commentary as logged by a science party watchstander during a dive. Pre-configured event hot buttons ease comment entry and standardize vocabulary, and we suggest that prior to the cruise you obtain or develop a hot button list according to the standards of your research community.
Jason can carry a 400 kHz Reson Seabat 7125 multibeam sonar. Use of the Seabat 7125 should be arranged in the pre-cruise process, and the chief scientist may wish to bring personnel who specialize in the production of bathymetry maps. The Jason at-sea data processor will produce a quick-look gridded product that is based on a first-cut renavigation and multibeam soundings that have been processed using automated scripts.
The cruise data package will be placed on hard drive and will consist of
- all raw Jason sensor
- video as described
- still images, raw and converted as described
- tables (.csv) of sensors data, subsampled and
- metadata and
- Post-processed navigation
- Quick-look multibeam maps and raw multibeam ping files, when
- VirtualVan, provided by two methods:
- network-independent html hierarchy that can be viewed using a web
- after the cruise on password-protectable server at http://4dgeo.whoi.edu/jason
Data Package Media
We will provide a portable hard drive system and will deliver the data package on it to the chief scientist at the end of the cruise. The standard filesystem for the package is ExFAT, which is compatible with Windows Vista and later, MacOSX Snow Leopard and later, and linux with extensions. Depending on operational demands, the Jason data processor may be able to provide intermediary versions of the data package throughout the cruise, and may be able to provide copies to other cruise PIs (who must provide hard drive media). The media containing the data package will be suitable for transport and temporary housing of the data, but should not be used for permanent storage. Once back at your institution, please be sure to transfer the data to enterprise quality storage.
When data package is delivered at the end of the cruise, chief scientist will be asked to:
(1) review a form that describes the package inventory and provides details for returning the drives to WHOI and acknowledge delivery of the package.
(2) assign embargo duration on the various data components (NSF policy states maximum 2-years).
(3) name institutions for whom acknowledgement is due when cruise data is used for outreach or commercial purposes.