Difference between revisions of "SREM"

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(Design, performance and calibration documentation)
(Design, performance and calibration documentation)
Line 6: Line 6:
!scope="col"| Logic
!scope="col"| Logic
!scope="col"| Particle
!scope="col"| Particle
!scope="col"| Energy (<math>M\!e\!v</math>)
!scope="col" align ="center"| Energy (<math>M\!e\!v</math>)
|width="50" | TC1
|width="50" | TC1
|width="55" | D1
|width="55" | D1
|width="110" align ="center"|protons
|width="110" |protons
|width="110"  |>20
|width="110"  |>20

Revision as of 17:55, 18 July 2012

Design, performance and calibration documentation[edit]

SREM counters
Name Logic Particle Energy ([math]M\!e\!v[/math])
TC1 D1 protons >20
S12 D1 protons 20 - 550
S13 D1 protons 20 - 120
S14 D1 protons 20-27
S15 D1 protons 20-34
TC2 D2 protons >39
S25 D2 ions 150-185
C1 D1[math]*[/math]D2 coinc. protons 40-50
C2 D1[math]*[/math]D2 coinc. protons 50-70
C3 D1[math]*[/math]D2 coinc. protons 70-120
C4 D1[math]*[/math]D2 coinc. protons >130
TC3 D3 electrons >0.5
S32 D3 electrons 0.55 - 2.3
S33 D3 protons 11-90
S34 D3 protons 11-30
PL1 D1 Dead Time NA
PL2 D2 Dead Time NA
PL3 D3 Dead Time NA

Processed data[edit]

Description of the product[edit]

The SREM data files contain calibrated data for the different energy and particle species channels available in the SREM. Each data file contains 24 hours of data - from midnight to midnight (note this is not an OD) - with the date covered by the file easily identifiable through the file name.



Input Data[edit]

SREM calibrated data was produced from the SREM raw data acquired during the entire mission.

Related Products[edit]

Data for the SREM on board Herschel can be retrieved from the Herschel Science Archive.

SREM data from previous missions can be retrieved from the SREM archive at the Paul Scherrer Institut (PSI).

Data format[edit]

  • Naming convention
The files containing the SREM calibrated data will have a name of the form SREMPlanck_PACC_YYYYMMDD.fits where PACC stands for Processed ACCumulated data and YYYYMMDD is the date the data in the file was acquired.
  • Units
  • Format
Each file contains three binary table extensions named CDFFITS1,CDFFITS2 and CDFFITS3. The first extension contains the accumulated counts data, the second extension the labels to identify the data in the first extension and the third extension the total radiation dosis. The contents of each extension are as follows.
Column Name Contents Format Unit
EPOCH vector containing 1 string with UTC for center of accumulation interval in ISO format (YYYY-MM-DDTHH:MM:SS.MMMZ) A24 NA
COUNTRATE vector containing 15 elements (1 for each channel) with counts for accumulation period identified in the EPOCH column E15.4 [math]s^{-1}[/math]
ORBIT position of the SREM in the XXX frame E15.4 [math]K\!m[/math]
ATTITUDE TBW E15.4 [math]NA[/math]
PROT FITQUAL this is a another keyword I1 [math]NA[/math]
ODPF this is a another keyword E15.4 [math]H\!z[/math]
ODPFERR this is a another keyword E15.4 [math]H\!z[/math]
ELEC FITQUAL this is a another keyword I1 [math]H\!z[/math]
ODEF this is a another keyword E15.4 [math]H\!z[/math]
ODEFERR this is a another keyword E15.4 [math]H\!z[/math]
ANISOTROPY this is a another keyword E15.4 [math]NA[/math]
TEMPERATURE 2 element vector containing temperature of the two detector heads at each EPOCH E15.4 [math]^\circ\!C[/math]

Column Name Contents Format Unit
EPOCH this is a keyword [math]K\!m^2[/math]

Column Name Contents Format Unit
RADEPOCH this is a keyword A24 [math]K\!m^2[/math]
RADFET this is a another keyword E15.4 [math]H\!z[/math]
  • N. Of Files
1500 (TBC)

Note: SREM calibrated data files where initially provided in the Common Data Format (cdf) format. This has traditionally been the preferred data format for SREM on board previous ESA missions. However, as cdf is not widely used in the astrophysics community it was later agreed with the provider that fits files should also be provided. This meant taking the original cdf format and converting it to fits. The original cdf files can be retrieved from the SREM site at the PSI.

Header keywords[edit]

For data provided in the form of fits files a table containing a description of all the header keywords should be included here. The table should follow this format

Keyword Name Description Unit
Keyword1 this is a keyword [math]K\!m^2[/math]
Keyword2 this is a another keyword [math]H\!z[/math]

Space Radiation Environment Monitor

Operation Day definition is geometric visibility driven as it runs from the start of a DTCP (satellite Acquisition Of Signal) to the start of the next DTCP. Given the different ground stations and spacecraft will takes which station for how long, the OD duration varies but it is basically once a day.

Universal Time Coordinate(d)

To be confirmed

European Space Agency