Level 1 of Lyra data consist in a set of four (seven, when acquisition is performed with two units at the same time) fits files:
These files contain a common primary header and a secondary header, which depends on the file type (std, met, cal, rej). The primary header has the following configuration:
KEYWORD | EXAMPLE OF VALUE | COMMENT |
---|---|---|
SIMPLE | T | Written by PyFits |
BITPIX | 8 | array data type |
NAXIS | 0 | number of array dimensions |
EXTEND | T | File contains extensions |
ORIGIN | ’ROB-SIDC’ | |
TELESCOP | ’PROBA2’ | |
INSTRUME | ’LYRA ’ | |
OBJECT | ’EUV solar irrad’ | |
OBS_MODE | ’nominal standard’ | std., ecl., cal. (std. or bak.), met., or rej. |
DATE | ’2009-07-31’ | FITS file creation date (yyyy-mm-dd) |
DATE-OBS | ’2009-07-30T00:00:00.000’ | UTC start of observation |
DATE-END | ’2009-07-30T23:59:59.990’ | UTC end of observation |
DATE-BUP | ’2010-05-01T00:00:00.004000’ | UTC start of update |
DATE-EUP | ’2010-05-01T21:41:22.150995’ | UTC end of update |
DATASRC | ’Redu ’ | Receiving ground station |
ALGOR_V | ’EDG=2.1 ’ | softs versions |
LEVEL | ’1 ’ | Calibration level |
CAL_FILE | lyra_cal_20090730-000000’ | File version number |
UNITS | ’2 ’ | |
FILENAME | ’lyra_20090730-000000_lev1_std_v01.fits’ | Name of this FITS file |
END |
The standard file contains all the acquired samples corresponding to uncalibrated solar signal measurements.
"Uncalibrated" does not only mean that raw LYRA data number per unit time (DN/ms, in this case) are shown instead of physical units; the curves also still include a long-term trend due to instrumental degradation, dark currents (which are not substracted at this level), daily and orbital variations due to on-board temperature changes, regular disturbances per orbit due to spacecraft rotations, and possible disturbances due to commanding. Gaps may be caused by missing downlinks or calibration campaigns.
As an illustration, see the curve below:
The keywords contained in the secondary header are:
KEYWORD | EXAMPLE OF VALUE | COMMENT |
---|---|---|
XTENSION | ’BINTABLE’ | binary table extension |
BITPIX | 8 | array data type |
NAXIS | 2 | number of array dimensions |
NAXIS1 | 41 | length of dimension 1 |
NAXIS2 | 7488 | length of dimension 2 |
PCOUNT | 0 | number of group parameters |
GCOUNT | 1 | number of groups |
TFIELDS | 6 | number of table fields |
TTYPE1 | ’TIME ’ | TIME in UTC (yyyy-mm-dd) |
TFORM1 | ’1D ’ | TIME data type: Real*8 (double precision) |
TUNIT1 | ’s ’ | TIME physical unit: seconds of day |
TTYPE2 | ’CHANNEL1’ | CHANNEL1: Lyman alpha |
TFORM2 | ’1D ’ | CHANNEL1 data type: Real*8 (double precision) |
TUNIT2 | ’kHz ’ | CHANNEL1 physical unit: kiloHertz |
TTYPE3 | ’CHANNEL2’ | CHANNEL2: Herzberg |
TFORM3 | ’1D ’ | CHANNEL2 data type: Real*8 (double precision) |
TUNIT3 | ’kHz ’ | CHANNEL2 physical unit: kiloHertz |
TTYPE4 | ’CHANNEL1’ | CHANNEL3: Aluminium filter |
TFORM4 | ’1D ’ | CHANNEL3 data type: Real*8 (double precision) |
TUNIT4 | ’kHz ’ | CHANNEL3 physical unit: kiloHertz |
TTYPE5 | ’CHANNEL1’ | CHANNEL4: Zirconium filter |
TFORM5 | ’1D ’ | CHANNEL4 data type: Real*8 (double precision) |
TUNIT5 | ’kHz ’ | CHANNEL4 physical unit: kiloHertz |
TTYPE6 | ’QFACTOR ’ | QFACTOR: calculated TIME quality factor |
TFORM6 | ’1B ’ | QFACTOR data type: Interger*1 (byte) |
TUNIT6 | ’ ’ | QFACTOR physical unit: none |
EXTNAME | ’FREQ LEVEL 1’ | Name of binary table extension |
END |
This file contains all the data (DN/ms) dedicated to the calibration of the instrument:
The secondary header is similar than in the case of a standard file.
This file gathers all the samples that must be rejected because:
The secondary header is similar than in the case of a standard file.
Those files contain the information that will be needed to calibrate the data. It is composed of three tables:
The keywords contained in the header of the first table are:
KEYWORD | EXAMPLE OF VALUE | COMMENT |
---|---|---|
XTENSION | ’BINTABLE’ | binary table extension |
BITPIX | 8 | array data type |
NAXIS | 2 | number of array dimensions |
NAXIS1 | 28 | length of dimension 1 |
NAXIS2 | 2900 | length of dimension 2 |
PCOUNT | 0 | number of group parameters |
GCOUNT | 1 | number of groups |
TFIELDS | 5 | number of table fields |
TTYPE1 | ’TIME_UTC ’ | TIME in readable format |
TFORM1 | ’26A ’ | TIME data type: String |
TUNIT1 | ’s ’ | TIME physical unit: seconds of day |
TTYPE2 | ’TIME ’ | TIME in seconds of the day |
TFORM2 | ’D ’ | TIME data type: Real*8 (double precision) |
TUNIT2 | ’s ’ | TIME physical unit: seconds of day |
TTYPE3 | ’TEMPERATURE’ | TEMPERATURE of LYRA detectors |
TFORM3 | ’E ’ | TEMPERAT. d. type: Real*4 (floating point) |
TUNIT3 | ’deg C ’ | TEMPERATURE physical unit: degree Celcius |
TTYPE4 | ’POINTING’ | POINTING calculated with SPICE (yaw,pitch,roll) |
TFORM4 | ’2E ’ | POINTING data type: Real*4 (floating point) |
TUNIT4 | ’arcsec ’ | POINTING physical unit |
TTYPE5 | ’DISTANCE’ | DISTANCE calculated with SPICE |
TFORM5 | ’D ’ | DISTANCE data type: Real*8 (double precision) |
TUNIT5 | ’km ’ | DISTANCE physical unit: km between s/c and Sun |
EXTNAME | ’HK LEVEL 1’ | Name of first metadata tableHK |
END |
The keywords contained in the header of the second table are:
KEYWORD | EXAMPLE OF VALUE | COMMENT |
---|---|---|
XTENSION | ’BINTABLE’ | binary table extension |
BITPIX | 8 | array data type |
NAXIS | 2 | number of array dimensions |
NAXIS1 | 45 | length of dimension 1 |
NAXIS2 | 1 | length of dimension 2 |
PCOUNT | 0 | number of group parameters |
GCOUNT | 1 | number of groups |
TFIELDS | 11 | number of table fields |
TTYPE1 | ’TIME_UTC ’ | UTC TIME |
TFORM1 | ’26A ’ | UTC data type: A26 |
TUNIT1 | ’s ’ | UTC seconds |
TTYPE2 | ’TIME ’ | TIME in seconds of the day |
TFORM2 | ’D ’ | TIME data type: Real*8 (double precision) |
TUNIT2 | ’s ’ | TIME physical unit: seconds of day |
TTYPE3 | ’HEAD ’ | HEAD used for detection (1, 2, 3, off=0) |
TFORM3 | ’B ’ | HEAD data type: Integer*1 (byte) |
TUNIT3 | ’ ’ | HEAD physical unit: none |
TTYPE4 | ’MODE ’ | MODE: nominal=1 or backup=0 |
TFORM4 | ’B ’ | MODE data type: Integer*1 (byte) |
TUNIT4 | ’ ’ | MODE physical unit: none |
TTYPE5 | ’COVER ’ | COVER: closed=1 or open=0 |
TFORM5 | ’B ’ | COVER data type: Integer*1 (byte) |
TUNIT5 | ’ ’ | COVER physical unit: none |
TTYPE6 | ’VISLED ’ | VISLED: visible led used=1 or not used=0 |
TFORM6 | ’B ’ | VISLED data type: Integer*1 (byte) |
TUNIT6 | ’ ’ | VISLED physical unit: none |
TTYPE7 | ’UVLED ’ | UVLED: ultraviolet led used=1 or not used=0 |
TFORM7 | ’B ’ | UVLED data type: Integer*1 (byte) |
TUNIT7 | ’ ’ | UVLED physical unit: none |
TTYPE8 | ’DARKCURR1’ | Dark current of channel1 detector |
TFORM8 | ’D ’ | DARKCURR1 data type: Real*8 (double precision) |
TUNIT8 | ’kHz ’ | DARKCURR1 physical unit: kilohertz |
TTYPE9 | ’DARKCURR2’ | Dark current of channel2 detector |
TFORM9 | ’D ’ | DARKCURR2 data type: Real*8 (double precision) |
TUNIT9 | ’kHz ’ | DARKCURR2 physical unit: kilohertz |
TTYPE10 | ’DARKCURR3’ | Dark current of channel3 detector |
TFORM10 | ’D ’ | DARKCURR3 data type: Real*8 (double precision) |
TUNIT10 | ’kHz ’ | DARKCURR3 physical unit: kilohertz |
TTYPE11 | ’DARKCURR4’ | Dark current of channel4 detector |
TFORM11 | ’D ’ | DARKCURR4 data type: Real*8 (double precision) |
TUNIT11 | ’kHz ’ | DARKCURR4 physical unit: kilohertz |
EXTNAME | ’STATUS LEVEL 1’ | name of binary table extension |
END |
The keywords contained in the header of the third table are:
KEYWORD | EXAMPLE OF VALUE | COMMENT |
---|---|---|
XTENSION | ’BINTABLE’ | binary table extension |
BITPIX | 8 | array data type |
NAXIS | 2 | number of array dimensions |
NAXIS1 | 41 | length of dimension 1 |
NAXIS2 | 1 | length of dimension 2 |
PCOUNT | 0 | number of group parameters |
GCOUNT | 1 | number of groups |
TFIELDS | 7 | number of table fields |
TTYPE1 | ’TIME_UTC’ | |
TFORM1 | ’26A ’ | |
TUNIT1 | ’s ’ | |
TTYPE2 | ’TIME ’ | TIME in seconds of the day |
TFORM2 | ’D ’ | TIME data type: Real*8 (double precision) |
TUNIT2 | ’s ’ | TIME physical unit: seconds of day |
TTYPE3 | ’MODE ’ | MODE: nominal=1 or backup=0 |
TFORM3 | ’B ’ | MODE data type: Integer*1 (byte) |
TUNIT3 | ’ ’ | MODE physical unit: none |
TTYPE4 | ’VFC1 ’ | VFC1 |
TFORM4 | ’2E ’ | VFC1 data type: Real*4 (floating point) |
TUNIT4 | ’ ’ | VFC1 physical unit: none |
TTYPE5 | ’VFC2 ’ | VFC2 |
TFORM5 | ’2E ’ | VFC2 data type: Real*4 (floating point) |
TUNIT5 | ’ ’ | VFC2 physical unit: none |
TTYPE6 | ’VFC3 ’ | VFC3 |
TFORM6 | ’2E ’ | VFC3 data type: Real*4 (floating point) |
TUNIT6 | ’ ’ | VFC3 physical unit: none |
TTYPE7 | ’VFC4 ’ | VFC4 |
TFORM7 | ’2E ’ | VFC4 data type: Real*4 (floating point) |
TUNIT7 | ’ ’ | VFC4 physical unit: none |
EXTNAME | ’VFC LEVEL 1’ | name of binary table extension |
END |