R87 DATA FORMAT


Here you find the description of the data files which are stored after the on-line acquisition and analysis performed by the DAGA2 System.

The archived sampled data are collected in direct access files on disc. The files are composed of records, all of the same length. There are different types of records. The types are:

1 sampled data

2 physical parameters

3 experimenters comments

4 DAGA system setup

All records have a header of at least 90 integer*2 words. The general structure of the records of the first type is

Header

First Data Field

Second Data Field (optional)

Third Data Field (optional)

Any data field has a particular sampling time. Any data field contains the samples of a certain number of channels, so the samples are, in the case of n channels,

CH1 sample 1

CH2 sample 1

............

CHn sample 1

CH1 sample 2

............

The first sample of each channel of each field has the same time, that is in the header.

There are different methods of representing the samples, using one or two bytes. In the case of the data of Explorer 1990-91, the samples are INTEGER*2 numbers and the sampling delta is 0.004883 V.

The meaning of the header words is

1 H_LREC rec.length (in words) 2 H_LHEA total header length (in w.)

3 H_KREC record number 4 H_ANTG gravitational antenna

5 H_KRUN run number 6 H_TIPR record type

7 H_LCO1 length of data field 1 8 H_NCA1 field 1 channels number

(total number of samples)

9 H_LCO2 length of data field 2 10 H_NCA2 field 2 channels number

11 H_LCO3 length of data field 3 12 H_NCA3 field 3 channels number

13 H_ANNO year 14 H_DOY day of the year

15 H_ORE hour 16 H_MIN minutes

17 H_SEC seconds 18 H_MSEC milliseconds

19 sampl. ms for field 1 20 sampling microsec. field 1

21 H_OFTIM time offset (ms) 22 H_ADC A/D code (tab.)

23 H_LHE1 header field 1 length 24 H_LHE2 header field 2 length

25 H_OPFL operation flag 26 -

27 H_NSIN number of sintet. 28 Freq. sint. 1 (Hz)

29 Freq. sint. 1 (10^-4 Hz) 30 " 2

31 " 2 32 " 3

33 " 3 34 " 4

35 " 4 36 H_AMP electr.ampl. [F16(1000)]

37 ----- H_CDIR coeff. V^2 -> K direct acquisit. [in RHEADER(19)]

39 ----- H_CRIS1 " " resonance nu_minus [in RHEADER(20)]

41 ----- H_CRIS2 " " " nu_plus [in RHEADER(21)]

43 V_0 trasducer voltage (V) 44 V_1

45 V_2 46 V_3

47 V_4 48 V_5

49 V_6 50 MUX_IND

51 KFFT_K n. of AAP FFT 52 KFFT_L lunghezza FFT

53 KFFT_NP number of AAP pieces 54 KFFT_I1 beginning of piece 1

55 KFFT_L1 length of piece 1 56 KFFT_I2 beginning of piece 2

57 KFFT_L2 length of piece 2 58 KFFT_I3 beginning of piece 3

59 KFFT_L3 length of piece 3 60 KFFT_NN n. of FFT in this rec (1 o 2)

61 H_TAU1 tau nu(-)[F16(.01 s)] 62 H_TAU2 tau nu(+) [F16(.01 s)]

63 H_SIG1 sigma " [F16(.0001 V)] 64 H_SIG2 sigma " [F16(.0001 V)]

65 H_S0 sqr.den.r.elet.[F16(1E-6)]66 H_VART total var. [F16(.0001 V^2)]

67 H_TEQR T_eq_rison [F16(1E-5 K)]68 H_TEQWB T_eq_wide_band [F16(1E-5 K)]

69 H_TEF1 T_eff nu(-)[F16(1E-6 K)]70 H_TEF2 T_eff nu(+) [F16(1E-6 K)]

71 H_TEFMF T_eff M.F.[F16(1E-6 K)]72 H_KSPET spectrum number of the run

73 ----- H_CAL calibration value by lock-in [in RHEADER(37)]

75 ----- H_CALSPET " " by spectrum [in RHEADER(38)]

77 H_TAUIMP_1 imposed tau_1 78 H_TAUIMP_2 imposed tau_2

[F16(.01 s)] [F16(.01 s)]

79 H_FBIMP imposed F.B. 80

[F16(.000001 V/sqr(Hz))]

81 H_CL1_CORR (dms) 82 H_CL2_CORR (dms)

83 H_D2TIM_CORR (dms) 84

85 86

87 88

89 90

91 92

93 94

95 96

97 98

99 100

N_MISx = H_LCOx / H_NCAx

H_TSAM = H(19)*1000 + H(20)

H_TSA1 = H_TSAM

H_TSA2 = H_TSAM*N_MIS2/N_MIS1

H_TSA3 = H_TSAM*N_MIS3/N_MIS1

F_SINx = synthesizer frequency x (real)

In the case of the data of Explorer 1990-91, the header values were

H_LREC 3000

H_LHEA 200

H_LCO1 1200

H_NCA1 12

H_LCO2 1600

H_NCA2 1

H_LCO3 0

H_NCA3 1

N_MIS1 100

N_MIS2 1600

N_MIS3 0

H_KRUN 192 (example)

H_KREC 1 "

H_TIPR 2 "

H_ANNO 1991 "

H_DOY 206 "

H_ORE 10 "

H_MIN 4 "

H_SEC 31 "

H_MSEC 850 "

H_TSA1 290816

H_TSA2 18176

H_TSA3 0

H_ADC 0

Some of the header variables were not defined at that time.

There were 12 channels in field 1 and 1 in field 2:

Field 1 [sampling time 290816 us]

1 _X- X nu -

2 _Y- Y nu -

3 _X+ X nu +

4 _Y+ Y nu +

5 CAL Calibration

6 DIR Direct Acquisition

7 ROB R out reson

8 SLB Sism l.freq.

9 SRF Sism resonance

10 EMM Electro-magn. mon.

11 CLK Top second

12 ALF Antenna low freq. or Jolly

Field 2 [sampling time 18176 us]

1 AAP Direct Acquisition after Anti-Aliasing Procedure