Calibrated Data Record (CDR)













Calibrated Data Record (CDR)

These data cover a wavelength range from the far ultraviolet (115-180 nm) through the middle ultraviolet (160-320 nm) to visible (250-600 nm) wavelengths, with an average spectral resolution of 0.6 nm. The UVVS Calibrated Data Records (CDRs) consist of calibrated data derived from MASCS UVVS Experimental Data Records (EDR)

Before the data can be used for scientific analysis, the EDR count rates must be converted to physical units and the data must be transformed into meaningful physical reference systems. Wavelength range and sensitivity of each grating step vary, as documented in the MASCS Calibration Report, MASCS_CAL_RPT.PDF, provided in the DOCUMENT directory.

Although the data spans Earth, Venus and Mercury fly-bys, UVVS began routine orbital observations of both the dayside and nightside exosphere on March 29, 2011. Altitude profiles for all previously detected neutrals (H, He, Na, K, and Ca ) except for He and K have been measured. The former has no emission features within the UVVS wavelength range (115 - 600 nm), and the latter has only one relatively weak feature there.

UVVS also scans for species that are known or are predicted to be present in the surface materials (e.g., Si, Al, S, Mn, Fe, and OH). Targeted sequences during the third and fourth Mercury years have been designed to measure the average exosphere content of species that are detected and substantially reduce the detection limits for the rest.

The CDR archive consists of 6 standard data products, 2 for each detector (FUV, MUV, VIS). These are identified as "UVVSCFUVHDR," "UVVSCFUVSCI," "UVVSCMUVHDR," "UVVSCMUVSCI," "UVVSCVISHDR," and "UVVSCVISSCI" where a science header table (HDR) contains the instrument command parameters for a given observation and and a science data table (SCI), contains the derived science data, and pointing information for each step of an observation.

The CDRs are in binary format and each is described by a detached PDS label . Detailed descriptions of the parameters in the label can be found in the label directory.

See the UVVS Calibrated and Derived Data Record Software Interface Specification Document for a detailed description of the instrument and the calibrated data. Also see uvvs_cdr_ds.cat provides further information.

A Quick Look Index

quick look index (TXT or EXCEL), which can be downloaded and edited into a personal finding list, has been derived from uscindex.lbl housed in the index directory

Binary to ASCII

An IDL tool which translates the CDR binary files is available (See side bar)