There are some requirements in the FITS files uploaded into OpenVLBI.com
Files uploaded must be smaller than 32MB.
A maximum of 10 files per user can be uploaded.
OpenVLBI needs a set of FITS keyword to setup each individual node.
INDI Library generates compatible FITS file with this format. After an INDI receiver, detector, correlator driver integration is done, an OpenVLBI compatible FITS will be generated and can be uploaded on the OpenVLBI.com dashboard.
Download a sample FITS HDU compatible with OpenVLBI.
These keywords may not be part of the standard FITS keywords, but can be added into the files’ headers before they’re uploaded, in particular these FITS keywords are necessary:
Keyword | Meaning | Type | Unit/Format | Notes |
BITPIX | Bit Depth | Integer | Sample type | 8, 16, 32, 64, -32, -64 are allowed values |
NAXIS | Dimensions | Integer | Only 2 is allowed by now | |
NAXIS1 | number of samples | Integer | ||
NAXIS2 | number of streams | Integer | Only 1 is allowed by now | |
SITELAT | Latitude of the observatory or antenna | String | DD:MM:SS.SS | |
SITELONG | Longitude of the observatory or antenna | String | DD:MM:SS.SS | |
SITEELEV | Elevation of the observatory or antenna | Float | Meters OSL | |
EPOCH | Unix timestamp of the start of the observation | Float | Unix Epoch offset | sub-second values are accepted |
OBJCTRA | object right ascension celestial coordinate | String | HH MM SS.SS | Precession reference J2000 |
OBJCTDEC | object declination celestial coordinate | String | DD MM SS.SS | Precession reference J2000 |
FREQ | Frequency of the observation | Float | Hz | Optical frequencies are allowed also |
BANDWIDT | Bandwidth of the observed spectra | Float | Hz | FREQ central bandwidth |
SRATE | Sampling rate | Integer | SPS | Capture samples per second |
APTDIA | Diameter of the telescope or dish | Float | Millimeters | |
FOCALLEN | Focal length of the telescope or dish | Float | Millimeters |