The Wide Field Coverage for Juno (WFCJ) program is synchronized with perijove passes of the NASA Juno mission. The Juno spacecraft orbit is very eccentric, allowing microwave and infrared scans of the atmosphere from a vantage point inside the planet's intense radiation belts. Although Juno is equipped with a visible wavelength public-outreach camera (JunoCam), the proximity to Jupiter during the perijove passes means that Juno itself cannot obtain regional-scale or global-scale imaging data to provide context for its own observations. The WFCJ program fills this gap with WFC3/UVIS imaging data. Some perijoves will be covered by a single orbit of HST imaging ("snapshot" coverage), while other perijoves will be covered by pairs of global maps ("global" coverage). Observing for two rotations allows the measurement of the speed of Jupiter's wind jets, which vary with latitude: the zonal wind profile (ZWP).
Juno's first perijove passes happened when Jupiter was too close to the Sun to be observed by Hubble. Perijove 3 (PJ3) was the first observable science pass, featuring global coverage.
The data are organized by sub-directory based on the perijove number they belong to. Each file name follows the formula described below. Each epoch is differentiated by a calendar year and a letter, e.g., "jupiter-2016pj03" is for perijove 3 during 2016.
- <yyyy> is the year
- <num> is the two-digit, zero-padded Perijove Number
- <filter> is the HST filter(s) used
- <ext> is the type of data product
A complete example file name is:
Data file types:
|_zwp.txt||Zonal wind profile (ASCII text format).|
|_zwp.fits||Zonal wind profile (FITS table format).|
|_globalmap.fits||Mosaic (projection) for the given filter.|
|_globalmap-medium.tif||Preview image (width x height ~ 900 x 450 px).|
|_globalmap-small.tif||Preview image (width x height ~ 450 x 225 px).|
|_nav.fits||Navigated image; FITS extensions give latitude, longitude, emission angle, and incidence angle for each pixel.|
|_crz.tif||Cleaned image preview corresponding to *_nav.fits file; image has been corrected for some cosmic rays, fringing (if relevant), and geometric distortion.|