HDF4 file: 32 data descriptors
library version = "HDF Version 4.2 Release 13, June 24, 2017"
data description = (text block)
| The file 'sis_level2_data_Bartels.h' is shown below, it was used to create the data in the Vgroup named 'VG_SIS_data_Bartels'.
| 
| /* Id: sis_level2_data_Bartels.h,v 1.1 2000/08/02 00:51:12 asc Exp asc $ */
| 
| #include "hdfi.h"
| #include "sis_sizes.h"
| 
| struct SIS_data_Bartels {
| 
|   /* UT time at the start of the periods */
|   int32   year;                         /* integer year */
|   int32   day;                          /* integer day of year */
|   int32   hr;                           /* hour of day */
|   int32   min;                          /* min of hour */
|   float32 sec;                          /* seconds */
|   float64 fp_year;                      /* floating point year */
|   float64 fp_doy;                       /* floating point Day of YearDOY */
|   float64 ACEepoch;                     /* UT time in sec since 1/1/96 */
| 
|   float32  flux_He[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_C[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_N[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_O[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ne[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Na[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Mg[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Al[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Si[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_S[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ar[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ca[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Fe[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ni[NUMBER_OF_ENERGY_BANDS];
| 
|   float32  cnt_He[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_C[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_N[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_O[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ne[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Na[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Mg[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Al[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Si[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_S[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ar[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ca[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Fe[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ni[NUMBER_OF_ENERGY_BANDS];
| 
|   float32 up_time_fraction;
| 
| };
data description = (text block)
| The file 'sis_level2_data_quiet_Bartels.h' is shown below, it was used to create the data in the Vgroup named 'VG_SIS_data_quiet_Bartels'.
| 
| /* Id: sis_level2_data_quiet_Bartels.h,v 1.1 2000/08/02 00:51:53 asc Exp asc $ */
| 
| #include "hdfi.h"
| #include "sis_sizes.h"
| 
| struct SIS_data_quiet_Bartels {
| 
|   /* UT time at the start of the periods */
|   int32   year;                         /* integer year */
|   int32   day;                          /* integer day of year */
|   int32   hr;                           /* hour of day */
|   int32   min;                          /* min of hour */
|   float32 sec;                          /* seconds */
|   float64 fp_year;                      /* floating point year */
|   float64 fp_doy;                       /* floating point Day of YearDOY */
|   float64 ACEepoch;                     /* UT time in sec since 1/1/96 */
| 
|   float32  flux_He[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_C[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_N[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_O[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ne[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Na[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Mg[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Al[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Si[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_S[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ar[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ca[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Fe[NUMBER_OF_ENERGY_BANDS];
|   float32  flux_Ni[NUMBER_OF_ENERGY_BANDS];
| 
|   float32  cnt_He[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_C[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_N[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_O[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ne[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Na[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Mg[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Al[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Si[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_S[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ar[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ca[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Fe[NUMBER_OF_ENERGY_BANDS];
|   float32  cnt_Ni[NUMBER_OF_ENERGY_BANDS];
| 
|   float32 up_time_fraction;
| 
| };
data description = (text block)
| The file 'sis_level2_factors_energy_levels.h' is shown below, it was used to create the data in the Vgroup named 'VG_SIS_factors_energy_levels'.
| 
| /* Id: sis_level2_factors_energy_levels.h,v 1.1 2000/08/02 00:52:03 asc Exp asc $ */
| 
| #include "hdfi.h"
| #include "sis_sizes.h"
| 
| struct SIS_factors_energy_levels {
| 
|   float32 factors[NUMBER_OF_ENERGY_BANDS];
|   float32 range_lower[NUMBER_OF_ENERGY_BANDS];
|   float32 range_upper[NUMBER_OF_ENERGY_BANDS];
| 
| };
file description = (text block)
| Created by the ACE Science Center (ASC) --
| ACE Science Center Level 2 Software Version:  1.5
| ACE Science Center Processing Date/Time: Sat Aug 15 08:51:06 2026 PDT
| For more info email us at: asc@srl.caltech.edu
| 
| 
| Note: There are SIS team written release notes presented in the
|       annotation section under Release Notes. These should be read.
| 
| For each Bartels Rotation (27.000 day period):
| 
| 	Type of Average		Number of Records
| 	-------------		-----------------
| 	256 second		9112 or 9113
| 	1 hour			648
| 	1 day			27
| 	Bartels Rotation	1
| 
| Determination of the fluxes and the counts are as follows:
| 
| 	flux = average of the 256 second flux over the time period
| 	       in units of particles/(cm^2*Sr*sec*Mev/nucleon)
| 
| 	counts = the total number of events during the timing period and is
| 		unitless; from these counts, the fractional uncertainty
| 		(0 to 1.0) in the flux can be calculated as 1/sqrt(counts).
| 
| Note: the natural integration cycle for the instrument hardware is 256 seconds
| long. Thus, the instrument cannot provide data on shorter time-scales.
| 
| The averaging of 256 sec data to form the longer time period data (1hr, 1day,
| and Bartels rotation averages) is simply:
| 
|     Average = Sum(flux)/(Number of samples with good data during the period)
| 
| The timing data refers to the start of the integration period in Universal
| Time (UT) and consists of:
| 
| 	year	-	int32 year
| 	day	-	int32 day of year
| 	hr	-	int32 hour of day
| 	min	-	int32 minute of hour
| 	sec	-	float32 seconds (accurate to millisec)
| 	fp_year -       float64 fractional year
| 	fp_doy	-	float64 fractional day of year
| 	ACEepoch-	float64 ACE epoch time in seconds since Jan 1, 1996
| 			at 0hr UT
| 
| For each element there are 8 fluxes in 8 energy bands. The ranges
| for the energy bands, along with the Geometry Factors, are listed in
| a separate annotation. NOte that the energy bands are different for
| each element.
| 
| The data values, which are all float32, are as follows:
| 
| Fluxes:
| 								Z number
|    	flux_He- He fluxes for 8 energy bands			    2
| 			in particles/(cm^2*Sr*sec*Mev/nucleon)
|      	flux_C - C fluxes					    6
|    	flux_N - N fluxes					    7
|    	flux_O - O fluxes					    8
|   	flux_Ne- Ne fluxes					   10
|   	flux_Na- Na fluxes					   11
|   	flux_Mg- Mg fluxes					   12
|   	flux_Al- Al fluxes					   13
|   	flux_Si- Si fluxes					   14
| 	flux_S - S fluxes					   16
|   	flux_Ar- Ar fluxes					   18
|   	flux_Ca- Ca fluxes					   20
| 	flux_Fe- Fe fluxes					   26
|   	flux_Ni- Ni fluxes					   28
| 
| Counts:
| 
| 	cnts_He - The number of helium events counted during the period
| 	cnts_C  - C event count
| 	cnts_N  - N event count
| 	cnts_O  - O event count
|   	cnts_Ne - Ne event count
|   	cnts_Na - Na event count
|   	cnts_Mg - Mg event count
|   	cnts_Al - Al event count
|   	cnts_Si - Si event count
| 	cnts_S  - S event count
|   	cnts_Ar - Ar event count
|   	cnts_Ca - Ca event count
| 	cnts_Fe - Fe event count
|   	cnts_Ni - Ni event count
| 
| 	up_time_fraction - Fraction of the timing period during which data was
| 		  collected
| 
| 	solar_activity_flag - 0 =  none;	less than threshold
| 			    - 1 =  activity;  greater than threshold
| 
| 	   where threshold* = (flux_He[0]+flux_He[1]+flux_He[2])/3.>1.e-4
| 			        OR
| 			      (flux_O[0]+flux_O[1]+flux_O[2])/3.>2.e-5
| 
| * Prior to Jan. 28, 1998, the second term for He is not used, i.e.
| 
| 		threshold = (flux_He[0]+flux_He[2])/2.>1.e-4
| 			        OR
| 			    (flux_O[0]+flux_O[1]+flux_O[2])/3.>2.e-5
| 
| For the Bartels rotation data, there is no solar_activity_flag. However, there
| are two different sums for all the flux and uncertainty data. The first sum
| is over all the data during the period regardless of the solar_activity_flag.
| The second sum is over only the quiet days, i.e. those days where the
| solar_activity_flag is zero.
file description = (text block)
| SIS Instrument team contact:
| 			Christina Cohen
| 	Phone:		626-395-6614
| 	Org:		California Institute of Technology
| 	City:		Pasadena, CA 91125
| 	Email:		cohen@srl.caltech.edu
| 
| 	SIS Co-Investigator:
| 			Christina Cohen
| 	Phone:		626-395-6614
| 	Org:		California Institute of Technology
| 	City:		Pasadena, CA 91125
| 	Email:		cohen@srl.caltech.edu
file description = (text block)
| ACE/SIS geometry factors and energy ranges
| 
| The Sensor Geometry Factors are determined by Monte Carlo estimation.  The
| nominal values are presented here. When fluxes are calculated, these nominal
| values are reduced to account for disabled matrix strips.
| 
| For data plotting purposes, the SIS team generally uses sqrt(Emin*Emax) as the
| energy at which each flux value is plotted. This value is also provided.
| 
| In units of cm^2*Sr, for each energy range, the nominal geometry factors are:
| 
| GF for He:			GF for C-Ni:
|  Range 0 = 42.8			 Range 0 = 42.8
|  Range 1 = 42.8			 Range 1 = 42.8
|  Range 2 = 41.2			 Range 2 = 41.4
|  Range 3 = 41.2			 Range 3 = 41.2
|  Range 4 = 39.0			 Range 4 = 39.0
|  Range 5 = 37.6			 Range 5 = 37.6
|  Range 6 = 32.2			 Range 6 = 32.2
|  Range 7 = 24.6			 Range 7 = 24.6
| 
| Range        Emin         Emax         sqrt(Emin*Emax)
|              (MeV/n)      (MeV/n)      (MeV/n)
| Helium-4
|       0      3.43000      4.74000      4.03215
|       1      4.74000      6.13000      5.39038
|       2      6.13000      7.29000      6.68489
|       3      7.29000      9.72000      8.41777
|       4      9.72000      13.5900      11.4932
|       5      13.5900      17.9600      15.6229
|       6      17.9600      29.3500      22.9592
|       7      29.3500      41.1900      34.7696
| Carbon
|       0      6.42600      8.62000      7.44259
|       1      8.62000      11.2300      9.83883
|       2      11.2300      13.4000      12.2671
|       3      13.4000      17.9400      15.5047
|       4      17.9400      25.1200      21.2286
|       5      25.1200      33.2100      28.8831
|       6      33.2100      54.3000      42.4653
|       7      54.3000      76.3400      64.3837
| Nitrogen
|       0      6.87440      9.33000      8.00863
|       1      9.33000      12.1800      10.6602
|       2      12.1800      14.5600      13.3169
|       3      14.5600      19.5100      16.8542
|       4      19.5100      27.3400      23.0955
|       5      27.3400      36.1700      31.4466
|       6      36.1700      59.1900      46.2699
|       7      59.1900      83.2600      70.2009
| Oxygen
|       0      7.29675      9.99000      8.53783
|       1      9.99000      13.0700      11.4267
|       2      13.0700      15.6300      14.2928
|       3      15.6300      20.9700      18.1042
|       4      20.9700      29.4200      24.8382
|       5      29.4200      38.9400      33.8469
|       6      38.9400      63.7700      49.8318
|       7      63.7700      89.7800      75.6655
| Neon
|       0      8.05460      11.1500      9.47675
|       1      11.1500      14.6400      12.7764
|       2      14.6400      17.5600      16.0337
|       3      17.5600      23.6200      20.3658
|       4      23.6200      33.2200      28.0117
|       5      33.2200      44.0200      38.2406
|       6      44.0200      72.2400      56.3915
|       7      72.2400      101.830      85.7683
| Sodium
|       0      8.14730      11.3400      9.61199
|       1      11.3400      14.9400      13.0161
|       2      14.9400      17.9400      16.3714
|       3      17.9400      24.1900      20.8319
|       4      24.1900      34.0800      28.7123
|       5      34.0800      45.2100      39.2525
|       6      45.2100      74.2800      57.9500
|       7      74.2800      104.770      88.2174
| Magnesium
|       0      8.68175      12.1600      10.2747
|       1      12.1600      16.0300      13.9615
|       2      16.0300      19.2600      17.5709
|       3      19.2600      25.9900      22.3734
|       4      25.9900      36.6400      30.8589
|       5      36.6400      48.6300      42.2114
|       6      48.6300      79.9700      62.3614
|       7      79.9700      112.900      95.0190
| Aluminum
|       0      8.74325      12.3000      10.3702
|       1      12.3000      16.2700      14.1464
|       2      16.2700      19.5800      17.8484
|       3      19.5800      26.4800      22.7701
|       4      26.4800      37.4000      31.4699
|       5      37.4000      49.7000      43.1136
|       6      49.7000      81.8300      63.7727
|       7      81.8300      115.600      97.2602
| Silicon
|       0      9.21060      13.0400      10.9593
|       1      13.0400      17.2600      15.0023
|       2      17.2600      20.7900      18.9430
|       3      20.7900      28.1300      24.1831
|       4      28.1300      39.7600      33.4432
|       5      39.7600      52.8700      45.8488
|       6      52.8700      87.1400      67.8756
|       7      87.1400      123.200      103.613
| Sulfur
|       0      9.70020      13.8300      11.5825
|       1      13.8300      18.3700      15.9392
|       2      18.3700      22.1700      20.1808
|       3      22.1700      30.1000      25.8325
|       4      30.1000      42.6600      35.8339
|       5      42.6600      56.8100      49.2292
|       6      56.8100      93.8500      73.0179
|       7      93.8500      132.900      111.681
| Argon
|       0      10.0980      14.5900      12.1379
|       1      14.5900      19.5400      16.8846
|       2      19.5400      23.6700      21.5061
|       3      23.6700      32.3000      27.6503
|       4      32.3000      46.0000      38.5461
|       5      46.0000      61.4400      53.1624
|       6      61.4400      101.810      79.0899
|       7      101.810      144.350      121.228
| Calcium
|       0      10.4856      15.1600      12.6080
|       1      15.1600      20.3000      17.5427
|       2      20.3000      24.6100      22.3514
|       3      24.6100      33.6000      28.7558
|       4      33.6000      47.8700      40.1053
|       5      47.8700      63.9900      55.3462
|       6      63.9900      106.220      82.4440
|       7      106.220      150.870      126.592
| Iron
|       0      10.6794      15.8300      13.0021
|       1      15.8300      21.5300      18.4613
|       2      21.5300      26.3000      23.7958
|       3      26.3000      36.3100      30.9023
|       4      36.3100      52.2200      43.5443
|       5      52.2200      70.2300      60.5592
|       6      70.2300      117.530      90.8522
|       7      117.530      167.660      140.375
| Nickel
|       0      11.2302      16.7100      13.6988
|       1      16.7100      22.7600      19.5018
|       2      22.7600      27.8500      25.1767
|       3      27.8500      38.5000      32.7448
|       4      38.5000      55.4700      46.2125
|       5      55.4700      74.6900      64.3666
|       6      74.6900      125.240      96.7170
|       7      125.240      178.960      149.710
file description = (text block)
| Release Notes for Level 2 SIS processing
| 
| C.M.S. Cohen
| 
| Time periods to use with some caution (updated: July 3, 2025):
|        -----START-----   -----STOP------
|   Year Mnth/Day DOY HR   Mnth/Day DOY HR  Note (see below for more details)
|  ----------------------------------------------------------------------------------
|   1997  11/07   311 16    11/11   315 16  thresholds raised on some stack detectors
|   1998  04/21   111 15    04/25   115 16  thresholds raised on all stack detectors
|   1998  08/25   237 16    08/27   237 17  thresholds raised on some stack detectors
|   2000  07/14   196 11    07/15   197 19  livetime < 10%
|   2000  07/14   196 16    07/18   200 19  thresholds raised on all stack detectors
|   2000  11/09   314 00    11/13   318 17  livetime < 10%
|   2001  04/03   093 06    04/03   093 07  livetime < 10%
|   2001  09/24   267 20    09/26   269 12  livetime < 10%
|   2001  10/02   275 06    10/02   275 08  livetime < 10%
|   2001  11/05   309 01    11/06   310 12  livetime < 10%
|   2001  11/23   327 06    11/24   328 15  livetime < 10%
|   2002  04/21   111 07    04/22   112 07  livetime < 10%
|   2003  10/28   301 13    10/30   303 21  livetime < 10%
|   2003  11/02   306 20    11/03   307 22  livetime < 10%
|   2003  12/04   338 06    12/04   338 08  livetime < 10%
|   2005  01/17   017 15    01/18   018 11  livetime < 10%
|   2005  01/20   020 06    01/20   020 16  livetime < 10%
|   2005  05/15   135 00    05/15   135 05  livetime < 10%
|   2005  09/10   253 09    09/12   255 22  livetime < 10%
|   2005  10/13   286 16    10/13   286 17  livetime < 10%
|   2005  11/02   306 16    11/02   306 18  livetime < 10%
|   2005  11/09   313 16    11/09   313 17  livetime < 10%
|   2006  12/07   341 15    12/08   342 06  livetime < 10%
|   2012  01/23   023 09    01/27   027 21  livetime < 10%
|   2024  01/04   004 00    01/11   011 00  livetime < 10% (times are approximate)
|   2024  10/09   283 00    10/11   285 00  livetime < 10% (times are approximate)
|   2024  10/20   294 00    11/15   320 00  livetime < 10% (times are approximate)
|   2024  11/19   324 00    12/31   366 24  livetime < 10% (times are approximate)
|   2025  01/01   001 00    03/12   071 00  livetime < 10-20% (times are approximate)
|   2025  03/31   090 12    04/02   092 00  livetime < 10-20% (times are approximate)
|   2025  06/01   152 00    06/02   153 00  livetime < 10-20% (times are approximate)
|   2026  01/19   019 12    01/29   029 00  He intensities are unreliable
| 
| February 5, 2026 cmsc
| 	 In processing the data for rotation 2624, it was noted that the short range He (e.g., range 0, 1, and 2)
| intensities are zero during the peak and decay of the large January 19, 2026 SEP event.  The team is investigating
| whether this is a result of the very low instrument livetime combined with lower priority given to short range
| He events or something related to the processing (at the moment it looks more like the former than the latter).
| The heavy ions (e.g., C-Ni) seem to be unaffected.
| 
| November 13, 2025 cmsc
| 	 As we continue to adjust the routine analysis of the SIS data, accounting for noisy and off strips, we
| have found that intensities from the two SIS telescopes differ by about 25-30% since approximately December 2024.
| We have yet to determine the source of this discrepancy, but it appears not to be element or energy dependent.
| The level 2 SIS data are an average of the two telescopes (for all elements except He), so we suggest users
| consider the systematic uncertainty in the level 2 intensities to be ~15% since late 2024.
| 
| July 3, 2025 cmsc
| 	We continue to monitor the matrix strips affected by high temperatures.  Ground processing has been updated
| to ignore the noisiest of the strips and data for rotations 2606 and beyond have been reprocessed.  There remain
| time periods where the livetime was extremely low (see table above) and the data are very uncertain during these
| times.  We are still investigating further possible corrections to the intensity calculations (particularly reduced
| geometry factor due to noisy and off strips).  Currently we assess that the intensities are accurate to ~20% for
| rotations 2606 and beyond.
| 	For rotations 2607 and 2608, unfortunately the data are still problematic and require more analysis to
| recover useful data.  While we continue this effort these rotations have fill data for all the intensities and time
| integrations.
| 
| 
| December 19, 2024 cmsc
| 	SIS continues to age and is affected by increasing temperatures (particularly in the winter months) which
| cause increased noise on the matrix strips.  Additional low livetime periods have been added to the table above.
| Routine processing for the intensities has been altered to correct for this up to (and including) rotation 2606.
| The team is investigating the cause of the increased noise in the remaining rotations to make better corrections.
| These rotations will be released once those corrections are detemined and included in the processing.
| 
| It should be noted that the effect of the low livetime/noisy strips is not possible to correct in either the browse
| or the real time (RTSW at SWPC) data, so related artifacts in those data will remain.  Of course, those data should
| not be used for science in any case.
| 
| January 11, 2024 cmsc
| 	As SIS ages, more matrix strips are susceptible to being noisy.  The team is currently investigating a
| time period where there is an unusually large number of strips that are occasionally noisy.  The effect on the
| data appears to be minimal, with primarily ranges 6 and 7 of carbon and nitrogen being affected at the ~20% level.
| This period (Jan 6, 2024 to present) has been added to the list above.
| 
| September 27, 2017 cmsc
| 	In reviewing the level 2 data for rotation 2511 (August 26 - September 22), a discrepancy was noticed between
| the two SIS telescopes in the rotation-averaged intensities for ranges 6 and 7.  The disagreements is ~10-30% for most
| elements C-Fe.  The SIS team is investigating possible causes.  In the meantime users are advised to consider the
| reported range 6 and 7 intensities during the SEP events of Sept 5-17 to be uncertain by ~20% (regardless of small
| statistical uncertainty indicated by the number of counts reported in the level 2 data).
| 
| January 27, 2016 cmsc
| 	The number of matrix strips with raised thresholds is limited to 20 for each telescope.  The number of strips
| requiring increased thresholds now exceeds this value for both telescopes and necessitates an increase in the overall
| M1 matrix detector threshold.  The current values are set at 1.9 and 2.6 MeV for the A and B telescopes,
| respectively.  The small M1 pulse heights for deep range He fall below these thresholds, resulting in significantly
| reduced efficiency for ranges 5, 6 and 7.  From DOY 348 (12/14) 2015 onwards these ranges for He will be set to fill
| data.  Ranges 0-4 for He and all ranges for C-Ni are unaffected.
| 
| Version 2.4   July 9, 2014 cmsc
| 	The SIS level 2 data were reprocessed from the start of mission to present to include a better calculation
| of the time-dependent geometry factor and a data cut to eliminate chance-coincidence events resulting from disabled
| strips.  This update has changed the hourly level 2 intensities by typically less than 10% (or by less than 1 sigma,
| based on the statistical uncertainties).  An exception is DOYs 341-343 of 2006 during which the heavy ion intensities
| for ranges > 2 are reduced by ~15%.
| 
| February 24, 2012 cmsc
| 	During time periods of extremely low livetime, the SIS on-board processing gives priority to analyzing
| and telemetering higher-energy, Z>=6 ions.  During such times the efficiency corrections for He and
| low-energy heavy ions are substantial and the raw counts can be quite low.  Users are cautioned
| that high-time resolution (e.g., 256 sec) intensities during such time periods may be very uncertain and are encouraged
| to use a lower-time resolution (e.g., 1 hour) products when the raw counts for the species of interest are low
| (raw counts are available through the level 2 data).  Below is a listing of time periods during which the SIS
| livetime was below 10% of nominal.  Users should be aware that the effect on He intensities can last longer than
| the effect on heavier ions and so should be cautious using 256-sec He data a few hours before and after the time
| periods listed below.
|                   START           STOP
|       Year      DOY    HR      DOY    HR
|       2000      196    11      197    19
|       2000      314     0      318    17
|       2001      93      6      93      7
|       2001      267    20      269    12
|       2001      275     6      275     8
|       2001      309     1      310    12
|       2001      327     6      328    15
|       2002      111     7      112     7
|       2002      143    10      143    10
|       2003      301    13      303    21
|       2003      306    20      307    22
|       2003      338     6      338     8
|       2004      208    22      208    22
|       2005      17     15      18     11
|       2005      20      6      20     16
|       2005      135     0      135     5
|       2005      253     9      255    22
|       2005      286    16      286    17
|       2005      306    16      306    18
|       2005      313    16      313    17
|       2005      349    16      349    16
|       2006      341    15      342     6
|       2012      23      9      27     21
| 
| Version 2.3	October 25, 2010 cmsc
| 	We identified and eliminated contamination from penetrating particles evident in the
| range 7 intensities.  The effect is most evident when examining long time integrations of
| quiet time periods.  The difference in the particle counts with the new and old cuts for an
| integrated quiet time period of 4/19/09 through 11/20/09 for the level 2 range 7 elements is given
| in the following table:
| 
|          Z        old cnts      new cnts   new/old
| -----------------------------------------------------
|       6.00000        4228        4077     0.964286
|       7.00000        1114        1074     0.964093
|       8.00000        5451        5410     0.992478
|       10.0000         869         857     0.986191
|       11.0000         239         157     0.656904
|       12.0000        1627        1415     0.869699
|       13.0000         283         215     0.759717
|       14.0000        1251        1184     0.946443
|       16.0000         210         171     0.814286
|       18.0000         159          91     0.572327
|       20.0000         391         189     0.483376
|       26.0000        1270        1250     0.984252
|       28.0000          64          63     0.984375
| 
| The effect on periods integrated over an SEP event are still being evaluated but are estimated
| to be below 5% for all level 2 elements.  Please note that the new cuts affect Range 7 intensities
| only (no changes have been made to the other ranges).
| 	All the data from mission start to date were reprocessed with the new Range 7 cut.
| 
| Version 2.2	March 22, 2010 cmsc
| 	We added a small correction for spallation within the instrument to the calculated
| intensities.  These corrections are greatest for deep range and heavier ions; they range from
| 0.9993 for range 0 He to 0.9227 for range 7 Ni (note: these are division factors; i.e., the
| intensities are divided by these numbers).
| 	All the data from mission start to date were reprocessed to incorporate these
| corrections.
| 
| Version 2.1 	June 6, 2008  cmsc
| 	The largest change to the level 2 analysis is the addition of more elements.
| We have added intensities for Na, Al, Ar, Ca, and Ni.  It should be noted that for Na
| (and potentially Al) the intensities during large SEP events maybe more uncertain
| due to spill over from the neighboring abundant elements.  Although we have not
| corrected the Na intensities on a case by case basis (which would have to be done by hand),
| the uncertainty in the absolute intensities should be <20% during high rate periods.
| 	It was determined that the detection efficiency for small pulse heights in one of
| the matrix detectors of the B telescope has fallen significantly since 2005.  This primarily
| affects long range He.  We have reprocess the data from 4 January 2005 onwards (Bartels
| rotations 2340 and beyond) to make use of only data from telescope A for calculating the  He
| intensities.  This effect is not a concern for the heavier elements so that processing has
| remained unchanged.
| 	A few minor changes in the analysis code have been made.  One deals with
| the handling of noisy strips.  These strips are ignored when a better alternative
| exists for the analysis.  Unfortunately, the code was not set up to handle a list of
| noisy strips that was not in strip number order or to account for reactivated off strips.
| The code has been updated to correctly handle these situations.  A second item is
| that the code has been updated to automatically calculate the revise geometry factor
| based on the current listing of off strips.
| 
| Version 2.0     April 18, 2007	cmsc
| 	Major upgrade (including a new major program) of the level 2
| processing has been done.  The previous level 2 program (level2_flux.pro)
| is no longer being used.  The required program and subroutines are given
| below.
| 	The largest change in the processing will be evident in the range 0
| intensities.  This is primarily due to a new analysis check which removes
| events that penetrated deeper in the instrument but were incorrectly tagged
| as range 0 events due to incomplete collection of the deeper range pulse
| heights.  The upgraded analysis will result in lower range 0 intensities
| in general.
| 	Another large change is evident in the range 7 He intensities.  This
| is due to a reanalysis of the trigger levels required for deep range He.
| The upgraded analysis will result in higher range 7 He intensities in some
| time periods (particularly quiet times).
| 	A listing of the current analysis checks and cuts is given below.
| For reasons of brevity the descriptions are terse, but feel free to contact
| Christina Cohen (cohen@srl.caltech.edu) for a more complete description/
| explanation.
| 	We remind users that effects due to low livetime conditions are
| still present in the data.  When particle intensities are very high (generally when
| the >10 MeV Proton rate exceeds ~2000 (cm^2-sr-sec)^-1) large corrections
| for low instrument livetime and pileup are somewhat uncertain.  This may result
| in the reported absolute intensities to be low (by an amount that is undetermined
| at the moment, but probably less than a factor of 10).  Since all the Z >= 6
| intensity calculations involve the same livetime, the relative intensities of
| the heavy ions should be reasonably accurate even during these high rate periods.
| 	Users of daily and Bartel rotation averaged files should be aware of
| the limitations of calculating uncertainties based on the square root of the reported
| number of particles (i.e., counts).  For averages that include time periods of
| very low livetime, the average intensities may be dominated by counts accumulated
| during the those low livetime portions.  Since the counts are typically low during
| these periods, the uncertainty of the corresponding intensity is high.  This should
| be taken into account when calculating uncertainties for the full time-average period,
| but will not be if the user calculates uncertainties based on sqrt(counts).  We
| encourage users to examine the intensities and counts for a higher time resolution
| product during such instances to correctly assess the uncertainties.
| 
| 	Current analysis checks/cuts (new items are indicated by *):
| - removes stim events
| - corrects geometry factor for 15 off strips (through 2002 1/21)
| - includes a patch for noisy strips (ignores strips considered to be noisy - time
|   dependent)
| - removes out of geometry events
| - requires He events to be in buffers <= 60
| - requires HIZ events to be in buffers > 60
| - corrects for priority system and livetime
| -*corrects range based on low pha energies before stopping detector (ranges 3-7,
|   not for He)
| -*cuts based on time to peak
| -*uses better gains and offsets for matrix energy calculations
| -*adds neighboring matrix strips together
| -*uses better matrix thickness maps
| -*cuts based on consistency between ground and high voltage sides of detectors
| -*better cuts based on Z consistency
| -*He R7 uses T4 for dE in one of the Z calculations rather than T1
| -*cut based on coincidence with He for range 0 HIZ events
| -*cut based on consistency between energy deposited in stack and matrix detectors
| -*cut requiring range 0 HIZ events to have a minimum energy deposited in M2
| -*cut requiring trajectory to land inside both matrix detectors
| - buffer rate spike filter applied
| - changes range 0 He data by factor of 1.6 and zeros out range 1 He data prior to
|   1998 1/28 22:40 due to thresholds
| - livetime includes correction for timing window
| 
| 	Processing prior to ASC processing:
| Primary Program:  make_level2.pro
| Language:  IDL
| Required Subroutines:  read_calcfile, read_calcfile_HHe, fluxcalc, various standard
|                        ACEware routines
| Run on files:  *.HIZ and *.HHe, created by make_calcfiles* which runs read_datafile_se1_pro
|                these files are stored in 10 day increments on /home/idunn1/cohen/
| 
| 
| Program:  level2_flux.pro
| Language:  IDL
| Required Subroutines:  pha_livetime.pro, various ACEware routines
| 
| Version 1.6     November 17, 2005       cmsc
| 	Code has been added to the level 2 processing to ignore signals
| from known noisy strips on the matrix detectors.  This should improve the
| trajectory calculations and subsequently the elemental resolution leading
| to more accurate intensities.  The effect was most noticable for Bartel
| rotations 2349 and 2350.  These have been reprocessed.
| 
| 
| Version 1.5     January 22, 2002 	cmsc
| 	Data from several big events (most notably the July 14, 2000
| and November 9, 2000 events) have been added to the level 2 dataset.
| During the highest-rate portions of these events (see below), large
| corrections are necessary for pileup and instrument livetime which are
| somewhat uncertain.  The resulting reported absolute intensities near
| the peaks of these events are probably low and for the singles rates
| (such as the >10 MeV Proton rate) can be uncertain by as much as a
| factor of 10.  It is expected that the heavy ion (Z >= 6) intensities
| will be uncertain by a smaller factor but the precise amount is
| unknown at this time.  Since all Z >= 6 intensity calculations involve
| the same livetime, the relative intensities during these events should
| be reasonably accurate.  In general, these livetime issues are a
| concern when the >10 MeV Proton rate exceeds ~2000 (cm^2-sr-sec)^-1.
| 
|             High-rate, suspect periods:
|         2000  7/14 12:00 -  7/14 16:00 (when thresholds were changed)
| 	2000 11/9  00:00 - 11/10 00:00
|         2001 11/5  16:00 - 11/6  08:00
|         2001 11/23 12:00 - 11/24 16:00
| 
| 	Users are further cautioned that during the November 9, 2000
| event there was a noisy strip on SIS that drove the livetime down
| precipitously.  This resulted in a substantially reduced number of
| good events being telemetered.  Users will see the effects of this
| most strongly in the scant Fe counts during the peak of this event.
| 
| 
| Version 1.5     January 1, 2001 	cmsc
| 	A new formula for the event livetime was determined that
| is more accurate than the simple instrument reported livetime during
| time periods when the livetime is very low.  This correction results
| in more accurate intensities of all heavy ions during several big events.
| Bartel rotations during which these events occurred were reprocessed:
| 
| 	2283
| 	2275
| 	2257
| 	2256
| 	2254
| 	2253
| 	2249
| 	2243
| 
| 
| Version 1.3   	October 12, 1999	cmsc
| 
| 	It was determined that long range He often may not trigger the T1
| detector causing the event to be thrown out by the current z consistency cuts.
| This caused range 7 He fluxes to be artificially low.  One of the two consistency
| cuts for He was eliminated and resulted in an approximate increase in the range
| 7 flux by a factor of 2.
| 
| 	It has also been observed that in time periods during which the detector
| thresholds were changed (during 3 large solar events) the low Z, high range fluxes
| are artifically low.  This is probably due to failure of events to trigger
| the T1 detector and and being thrown out by one of the consistency checks.  No
| correction has been made and the user is cautioned about low fluxes in the high
| ranges for low Z elements appearing during the following time periods:
| 
| 97/11/07 16:00 - 97/11/11 16:30
| 98/04/21 15:10 - 98/04/25 16:05
| 98/08/25 16:40 - 98/08/27 16:55
| 
| 	Quiet time selection is being made by the ACE Science Center.
| Examination of the quiet time data indicates there the low range He data are not
| entirely quiet.  Since tightening the quiet time criterion may eliminate quiet
| time heavy ion data, we have chosen not to change the criterion but suggest that
| users be aware that quiet time low range He may still contain some solar activity.
| 
| 
| Version 1.2	September 10, 1999	cmsc
| 
| 	Better z consistency cuts were determined.  This will increase the flux
| levels at the high ranges (6 and 7) by about ~10% for CNO, by about ~5% for Ne,
| Mg and less than 1% for Si-Fe.  Currently we suggest a 5% systematic error be
| added to all the flux uncertainties.  In comparing the range 7 data with range
| 2 data from CRIS we have found an ~10% discrepancy.  We will continue our efforts
| to determine the cause of the discrepancy and correct it, but currently take it
| as a measure of how accurately we know the absolute flux levels.
| 
| 	Headers on the files were changed to tabulate the new Z consistency cuts
| (which are now a function of Z, range and which Z estimates are being compared -
| there are 2 comparisons being made).  See program for a complete listing of the
| zcut boundaries.
| 
| ** All data were reprocessed as of September 10, 1999 **
| 
| 
| Version 1.1	August 13, 1999		cmsc
| 
| 	Better nominal geometry factors were obtained.  The following are now used:
| 
| GF for He:			GF for C-Fe:
|  Range 0 = 42.8			 Range 0 = 42.8
|  Range 1 = 42.8			 Range 1 = 42.8
|  Range 2 = 41.2			 Range 2 = 41.4
|  Range 3 = 41.2			 Range 3 = 41.2
|  Range 4 = 39.0			 Range 4 = 39.0
|  Range 5 = 37.6			 Range 5 = 37.6
|  Range 6 = 32.2			 Range 6 = 32.2
|  Range 7 = 24.6			 Range 7 = 24.6
| 
| Note:  the entry on Jun 29, 1999 regarding actual geometry factors used still applies,
| i.e., these nominal geometry factors listed above are reduced to account for disabled
| matrix strips when fluxes are calculated.
| 
| 	Instead of providing errors in the flux for each range we are now
| providing the raw number of counts in each range.
| 
| ** All data were reprocessed as of August 13, 1999 **
| 
| 
| August 5, 1999		cmsc
| 
| 	On Jan 28, 1998 at 22:40 UT the matrix thresholds on SIS were lowered.
| This resulted in a change in the SIS efficiency in measuring He fluxes which
| predominantly affects the range 0 and 1 data.  In order to make the He data
| prior to the threshold change available and useful to the community we have made
| the following modifications to the data.
| 
| For data prior to Jan 28, 1998 22:40 UT --
|   He range 1 is not given, the data in the files is fill data.
|   He range 0 has been increased by a factor of 1.6 which corresponds to our
| best estimate of the efficiency reduction related to the higher matrix thresholds
|   The quiet time flag is calculated using the average of the He range 0 and 2
| fluxes (rather than the average of the He range 0, 1, and 2 fluxes)
| 
| For data after Jan 28, 1998 22:40 UT --
|   He fluxes for all ranges are given.
|   The quiet time flag is based on the average of the He range 0, 1, and 2 fluxes.
| 
| 	On Feb 10, 1998 at 18:26 UT the H and He timers were altered which
| affects the amount of H and He livetime.  When examining the He data at maximum
| resolution (256 seconds), the difference in livetime results in a factor of 2.4
| increase in the minimum detectable He fluxes (i.e., the single count level) for
| all ranges.  When averaged over a longer time interval (1 hour or greater) it
| becomes clear that the actual measured flux value is unchanged by the timer
| command.
| 
| ** He data for the affected rotations (2241-2246) were reprocessed as of August 6, 1999 **
| 
| 
| Version 1.0		June 29, 1999		cmsc
| 
| 	A filter to search for and eliminate spikes in the rate data (used to
| convert to flux) was added to the pha_livetime.pro subroutine.  The algorithm
| for identifying spike is to compare each point to its 2 non-zero neighbors (one
| on each side) and if the point is greater (less) than a factor of 50 higher
| (lower) than both neighboring points the point is labeled as a spike.  The
| corresponding flux data for the entire 256 second period is zeroed out
| (regardless of Z).
| 	A filter to identify spikes in the calculated flux due to HIZ Z events
| tagged with a buffer ID corresponding to He or H was added to the
| level2_flux.pro program.  The bad data were identified by requiring all events
| with Z > 5 to have buffer ids < 60.
| 	The geometry factors were altered to reflect the fact that at launch 2
| strips (of 64) were off on detector M1B.  After 1997 Dec 8 (day 342) 17:42 UT, 4
| additional strips on M1B were turned off.  The nominal geometry factors assumed
| identical telescopes (i.e., gf(tel A) = gf(tel B)).  The correction made was to
| multiply the nominal geometry factor of telescope B by a factor of 62/64 from
| launch to day 342 17:42 UT and by a factor of 58/64 for times after day 342
| 17:42 UT.
| 
| ** All data were reprocessed as of August 3, 1999 **
| 
| 
| Version 0.1
| 
| 	Original program outputs 256-second data for a given Z range
| (corresponding to one element) for all 8 instrument ranges.  1 file is created
| for each element.
| 	Data are in flux units.  Uncertainties are fractional uncertainties and
| based on statistical uncertainties only (i.e., 1/sqrt(N)).  Currently range 8
| flux and uncertainties are set to 0.
| 	Nominal geometry factors and energy intervals are used:
| 
| GF for He:			GF for C-Fe:
|  Range 0 = 41.4			 Range 0 = 38.4
|  Range 1 = 41.4			 Range 1 = 38.4
|  Range 2 = 41.4			 Range 2 = 37.5
|  Range 3 = 40.3			 Range 3 = 36.7
|  Range 4 = 38.4			 Range 4 = 34.4
|  Range 5 = 37.0			 Range 5 = 33.1
|  Range 6 = 31.8			 Range 6 = 27.2
|  Range 7 = 24.5			 Range 7 = 19.4
| 
| (See program for nominal energy intervals)
| 
| 	Very loose z consistency cuts are made to the data.  Z1/Z0 and Z2/Z0 are
| required to be 1.0 +- 0.03, where Z0 is Z calculated using dE = sum of all
| previous detectors, E' = stopping detector, Z1 is Z calculated using dE = M1
| detector, E' = sum of all following detectors, and Z2 is Z calculated using dE =
| next to last detector, E' = stopping detector.
data description = (text block)
| The file 'level2_record_doy.h' is shown below, it was used to create the data in the Vgroup named 'VG_level2_record_doy'.
| 
| /* Id: level2_record_doy.h,v 1.1 2000/08/02 00:47:11 asc Exp $ */
| 
| #include "hdfi.h"
| 
| /* record year/DOY association */
| struct level2_record_doy {
| 
|   int32   record_number;             /* record number */
|   int32   year;                      /* integer year */
|   int32   day;                       /* integer day of year */
|   int32   days_jan_1_1996;           /* days since January 1, 1996 UT 0 hr*/
| 
| };
vgroup "VG_SIS_data_Bartels" class "VG_SIS_LEVEL2_DATA_BARTELS"
	vdata "SIS_data_Bartels" class "ACE sis data _Bartels": fields year, day, hr, min, sec, fp_year, fp_doy, ACEepoch, flux_He, flux_C, flux_N, flux_O, flux_Ne, flux_Na, flux_Mg, flux_Al, flux_Si, flux_S, flux_Ar, flux_Ca, flux_Fe, flux_Ni, cnt_He, cnt_C, cnt_N, cnt_O, cnt_Ne, cnt_Na, cnt_Mg, cnt_Al, cnt_Si, cnt_S, cnt_Ar, cnt_Ca, cnt_Fe, cnt_Ni, up_time_fraction; 1 records
vgroup "VG_SIS_data_quiet_Bartels" class "VG_SIS_LEVEL2_DATA_QUIET_BARTELS"
	vdata "SIS_data_quiet_Bartels" class "ACE sis data quiet__Bartels": fields year, day, hr, min, sec, fp_year, fp_doy, ACEepoch, flux_He, flux_C, flux_N, flux_O, flux_Ne, flux_Na, flux_Mg, flux_Al, flux_Si, flux_S, flux_Ar, flux_Ca, flux_Fe, flux_Ni, cnt_He, cnt_C, cnt_N, cnt_O, cnt_Ne, cnt_Na, cnt_Mg, cnt_Al, cnt_Si, cnt_S, cnt_Ar, cnt_Ca, cnt_Fe, cnt_Ni, up_time_fraction; 1 records
vgroup "VG_SIS_factors_energy_levels" class "VG_SIS_LEVEL2_FACTORS_ENERGY_LEVELS"
	vdata "SIS_factors_energy_levels" class "ACE sis factors_energy_levels": fields factors, range_lower, range_upper; 14 records
vgroup "VG_level2_record_doy" class "VG_LEVEL2_RECORD_DOY"
	vdata "level2_record_doy" class "level2_record DOY table": fields record_number, year, day, days_jan_1_1996; 1 records