10.0 Medium Frequency Receiver (MFR)

10.1 MFR Subsystem Description

This section of the RPWS Calibration Document augments the hardware overview given in Section 3 by providing a more detailed description of the Medium Frequency Receiver (MFR), a system based on designs flown on the ISEE, DE-1, Galileo, and CRRES spacecraft. The MFR processes signals from the Bx, Bz, Ex dipole, Ex+ monopole, Ex- monopole, or Ez monopole antennas, and provides electric field and magnetic field amplitude measurements over the frequency range 24 Hz to 12.6 kHz. The receiver design offers moderately good frequency and amplitude resolution, a balance in technical performance consistent with overall RPWS measurement objectives.

10.1.1 General MFR Characteristics

The MFR system sweeps over the frequency range 24 Hz to 12.6 kHz, and consists of three frequency bands each 1 octave wide. Designated 1, 2, and 3, each frequency band is divided into narrow frequency steps which are synthesized using a two-stage frequency conversion scheme. A block diagram of the MFR system is shown in Figure 10.1.1.1.

Each band uses a front end (IF) mixer to up mix the desired frequency of interest to a set frequency IF bandpass filter. A second fixed frequency (baseband) mixer down-converts the IF bandpass filter output to baseband frequencies. This baseband signal is logarithmically compressed, rectified and summed to a 0-5 volt DC output.

The primary mode of operation for the MFR is the Logarithmic Sweep mode. The Logarithmic Sweep mode provides 80 frequency steps (16 in Band 1, 32 each in Bands 2 and 3) with approximated logarithmic spacing over the frequency range of the receiver..

All 3 bands are driven from a front end buffer whose input is selectable between the Ex dipole, Ez, Bx, and Bz antennas. The LRP provides all control (antenna select, mixer reference) signals as well as processing the MFR bands 0-5.12 volts DC output signals. Regulated power for the MFR is provided by the RPWS power supply through the WFR.

10.1.2 Frequency Bands

The upper frequency limits of the three MFR frequency bands are determined by active filters which receive signals from the sensors and associated differential amplifiers through a filter driver amplifier. Lower frequency limits are imposed by the lower limit of the front end (IF) mixer chopping frequencies. The input filter cutoffs are scaled by a factor of eight relative to each other, which provides a frequency response of three octaves for the entire MFR. The bandpass filters provide rejection of out-of-band signals, which is required by the subsequent front end (IF) mixer stage. The passbands of the input filters are as follows:

Band #	Bandwidth

1	24 Hz - 200 Hz

2	200 Hz - 1600 Hz

3	1.6 kHz - 12.6 kHz

10.1.3 Frequency Selection

The MFR uses a frequency conversion scheme to synthesize a very narrow detection

passband. This narrow band is then stepped by varying the front end (IF) mixer clock signals to shift up the desired signal band into the IF filter passband. Mixed to 2.5 times the given band's frequency limit, the signal band is passed through the IF bandpass filter which excludes extraneous components from the subsequent constant-frequency mixing stage.

Band 1, using single sideband topology, employs two separate baseband mixers which combine the IF output signal with conversion frequencies f and f shifted by 90 degrees. This conversion produces a pair of baseband signals with upper and lower sidebands superposed, but with a phase difference of 180 degrees. A quadrature phase shift network then shifts the converted signals by an additional 90 degrees so that when the signals are summed, the upper sideband components add and the lower sideband components cancel. Because of the low frequency range of Band 1, a design using the double sideband detection method would result in an extremely low detection frequency. By using the single sideband detection approach, the detected bandwidth is at a higher frequency allowing faster stepping rates. Unlike Band 1, Bands 2 and 3 do use the double sideband method (due to board space limitations and wider allowable bandwidth).

For all three MFR bands, the baseband signals are then bandpass-filtered and processed by a logarithmic compressor stage that provides a DC analog value proportional to the logarithm of the input signal. The dynamic range of each compressor is in the order of 100 dB with 1 Vrms applied 5.12 V DC out. These DC output values are sampled by the LRP.

For each band, the mixing frequencies needed to generate the discrete frequency steps are provided by the frequency control logic (FCL). The MFR uses separate frequency generators for each band, allowing different stepping rates for the three bands. Because the lower frequency bands require longer time periods to stabilize at a given step before a measurement can be made, different stepping rates are needed in order to maximize the time resolution of measurements provided in each frequency band. Step selection and timing are managed by the LRP via reference clocks to the FCL. Although the MFR has the capability of being locked to a particular frequency step in any of the three bands, the normal manner of operation will be to step at regular intervals over the three frequency ranges as indicated below.

Mode	Band	Freq. Range	# Steps	Step Dwell	Sweep Time

Log	1	24 - 200 Hz	16	1	sec	16	sec

2	200 - 1600 Hz	32	0.5	sec	16	sec

3	1.6 - 12.5 kHz	32	0.25	sec	8	sec

The individual front end mixing frequencies for each band are selected to provide a logarithmic distribution of center frequencies. The center frequencies for the Logarithmic Sweep mode is shown in Table 10.1.3.1. Additional aspects of the MFR subsystem are discussed in detail in the following sections.

10.1.4 Mixing Signals

The MFR frequency bands are synthesized by a double conversion scheme as described

earlier, with variable front-end IF mixers providing the narrow band sweep capabilities of the receiver system, and back-end mixers providing the frequency conversion to baseband. All three bands receive mixer control clocks from the LRP. These signals are level shifted, divided down and phase shifted by the MFR frequency control logic so as to provide proper control signals to the front and rear mixers.

For bands 1 and 2, front-end IF mixing signals are derived directly from a programmable digital divide-by located on the LRP board. The LRP clock signals are level and phase shifted by the MFR FCL. These signals up convert the desired narrow band of interest to a fixed IF bandpass frequency. Band 3 uses the LRP clock signal as a reference clock. This reference is multiplied up to the required Band 3 mixer (IF) frequency using a current controlled oscillator within a phase locked loop (PLL). This is required since direct digital divide by would not provide the frequency resolution required of the receivers step frequency function. The PLL oscillator signal is then level and phase shifted to provide the signal needed by the front end mixer.

All three bands' back-end (baseband) mixers use a fixed frequency set at or near the IF bandpass center frequency. The reference signal is provided by the LRP and is digitally divided and shifted to the appropriate levels on the MFR board.

Table 10.1.3.1

MFR Logarithmic Center Frequencies (Hz)

Step	Band 1	Band 2	Band 3
1	23.8910	192.1108	1536.8867
2	26.2510	214.6289	1671.8125
3	29.1468	225.9814	1785.1016
4	32.4228	237.3965	1899.1719
5	36.2695	260.4165	2083.3320
6	40.8909	272.0229	2269.5547
7	46.5109	295.4307	2316.4336
8	52.8165	307.2329	2481.5547
9	60.4319	331.0381	2648.3047
10	69.4643	355.1138	2816.7148
11	80.0469	379.4644	3011.2422
12	92.3442	404.0947	3208.0039
13	107.2421	429.0103	3432.0820
14	124.3865	454.2153	3659.0898
15	144.8837	492.5771	3992.2891
16	169.0493	518.5288	4279.2383
17	558.0356	4651.2734
18	598.2544	4813.1094
19	639.2046	5086.1094
20	680.9058	5419.2148
21	723.3794	5758.4805
22	766.6470	6162.3164
23	825.6113	6575.0586
24	870.8198	7027.5117
25	932.4595	7490.9219
26	995.7109	7997.7500
27	1060.6372	8518.0195
28	1144.2549	9120.0586
29	1213.2041	9705.6328
30	1302.0835	10165.0117
31	1375.4399	11078.0430
32	1470.0942	11799.3281

10.1.5 Control Functions

Control functions are provided by the LRP board. The LRP provides the MFR with all variable front end mixing signals, fixed back end mixing signals, antenna selects, and accepts the MFR DC outputs. The LRP controls step and timing selection for each individual band. The variable conversion frequencies are generated when the LRP loads the appropriate control codes into a counter timer interrupt chip (an 82C54 located on the LRP). These outputs are used as the reference frequencies of the MFR FCL. Band 3 uses one of the timer outputs as a phase-locked loop (PLL) reference and multiplies up this reference for use as the front end mixer clock. Bands 1 and 2 use the remaining two outputs for inputs to their level and phase shifters that subsequently provide the mixing signals for each of their respective front end (IF) mixers. The LRP supplies a 125 kHz digital level signal for the MFR logic to generate the fixed back end (baseband) mixer signals. The LRP provides a two-bit antenna select signal and MFR data (0 to 5 volts) is accepted into the LRP by an A\D converter channel.

10.1.6 Antenna Selection

The MFR system is designed to process signals from either the Ex dipole, Ez monopole, Bx searchcoil, or the Bz searchcoil antenna providing information regarding wave amplitude. The sensors to be used are connected to the MFR inputs via analog switches which are controlled by the LRP in response to spacecraft commands. The following antennas may be selectively switched to the MFR receiver inputs:

LRP Command

MFRANT1 MFRANT0	Selected Antenna

0	0	Ex (dipole) *

0	1	Ez (monopole)

1	0	Bx (search coil)

1	1	Bz (search coil)

* It should be noted that the HFR can supply either the dipole Ex (default), or a monopole

(Ex+ or Ex-) antenna to the MFR.

10.1.7 Power

The instrument power supply provides the MFR with five regulated supply voltages. The supply voltages and expected average current loads are as follows:

+12 V	13.85 mA

+6 V	25.9 mA

+5 V	8.68 mA

-6 V	23.0 mA

-12 V	9.9 mA

The total power requirement for the MFR is approximately 628 mW.

10.1.8 Data Products

The MFR provides one DC voltage output per frequency band for a total of 3 analog values. The analog parameters are scaled from 0 to 5.12 V, which corresponds to a 100 dB dynamic range for measured signal amplitude. The lines carrying these voltages are sampled by the LRP at a rate determined by LRP software.

10.2.1 Conversion of Data Numbers to Science Units

This section describes the procedure for obtaining a calibrated data value from a MFR raw measurement.

1)	First the voltage lookup tables in Section 10.3.1 should be used to convert the data number
DN to a voltage represented by the symbol Vtable. Select the appropriate table corresponding to the band and step of interest. These tables are the conversions between the DN out of the instrument and the voltage difference between the Ex+ and Ex- antennas.

2)	Once the voltage Vtable is found, the sensor-dependent conversion factor must be used to
adjust the voltage. The voltage difference between the Ex+ antenna and the Ex- antenna is given the symbol VDEx. Since the tables in Section 10.3.1 are for the voltage difference between Ex+ and Ex- no conversion is necessary for VDEx. VDEx is equal to Vtable. The voltage between the Ex+ antenna and spacecraft ground is given the symbol VEx+. The voltage between the Ex- antenna and spacecraft ground is given the symbol VEx-. The voltage between the Ez antenna and spacecraft ground is given the symbol VEz. The voltage out of the Bx magnetic preamp is given the symbol VBxpa. The voltage out of the Bz magnetic preamp is given the symbol VBzpa. Figure 10.2.1.1 shows the location of each of these voltages.

The conversion factors and their symbols are listed below. The conversion factors convert the Vtable values to the voltage at the various sensors.

Symbol	Factor

CF+ex	1.0	Conversion factor for a monopole using the Ex+ antenna

CF-ex	1.0	Conversion factor for a monopole using the Ex- antenna

CFez	1.0	Conversion factor for the Ez antenna

CFbx	24.0	Conversion factor for the Bx Search Coil

CFbz	24.0	Conversion factor for the Bz Search Coil

The formulas for converting the Vtable value to the sensor input voltage are shown below.

VDEx	=	Vtable	(units are volts rms.)

VEx+	=	(CF+ex) * (Vtable)

VEx-	=	(CF-ex) * (Vtable)

VEz	=	(CFez) * (Vtable)

Vbxpa	=	(CFbx) * (Vtable)

Vbzpa	=	(CFbz) * (Vtable)

For the electric sensors there may be frequency dependent adjustments necessary because of the interaction of the antenna with the plasma, but these are dependent upon the plasma impedance. If the user wishes to adjust for these effects, see Section 6.0.

3)	The voltages at the outputs of the Search Coil preamplifiers must now be converted to
nanotesla. Table 10.2.1.1 contains the conversion factors for the Bx Search Coil and Figure 10.2.1.2 presents this data graphically. This conversion factor is frequency dependent and the value corresponding to the step of interest should be chosen. This conversion factor is given the symbol of CBxnt. The units of this factor are V/nT. Table 10.2.1.2 and Figure 10.2.1.3 present the conversion factors for the Bz Search Coil in tabular and graphical form. The conversion factor for the Bz Search Coil is given the symbol CBznt. It also has units of V/nT. To convert from voltage at the output of the Bx Search Coil preamplifier VBxpa must be divided by CBxnt. Likewise the voltage output of the Bz Search Coil must be divided by CBznt. This is shown in the following equations.

NTBx	=	Vbxpa / CBxnt	(units are nT rms.)

NTBz	=	Vbzpa / CBznt

NTBx is the field at the Bx Search Coil and NTBz is the field at the Bz Search Coil. At this point, we have meaningful physical units. For the electric antennas we have the voltage measured at the antenna elements. For the magnetic sensors we have the magnetic field in nanotesla at the sensors. Next the magnitude of the electric field for the electric antennas can be obtained. The voltages at the antennas are divided by the effective antenna length. This produces units of volts per meter. Here the effective lengths are defined as the physical distances between the geometric centers of the antennas for the Ex and the geometric center for the Ez antenna. The effective length for the Ex+ to Ex- dipole antenna configuration is given the symbol Exdelta. The Ex+ monopole effective length is given the symbol L+Ex. The Ex- monopole is given the symbol L-Ex. The Ez monopole is given the symbol LEz. See Section 6.3 for a more detailed discussion of the effective length of the antennas.

Effective Antenna Length in Meters for various mode configurations

Antenna	Effective Length(in meters)	Configuration

LExdelta	8.66	dipole

L+Ex	5.0	monopole

L-Ex	5.0	monopole

LEz	5.0	monopole

The electric antenna field on the Ex dipole is represented by VMExdelta, the electric field on the Ex+ monopole by VM+Ex, the electric field on the Ex- monopole by VM-Ex and the electric field on the Ez monopole by VMEz. The following equations show the method for calculating the electric antenna field on the antenna in volts per meter. These equations do not include effects due to the stray capacitive divider effects between the antennas and the spacecraft.

VMExdelta	=	(VDEx) / (LExdelta)

VM+Ex	=	(VEx+) / (L+Ex)

VM-Ex	=	(VEx-) / (L-Ex)

VMEz	=	(VEz) / (LEz)

4)	To obtain spectral density one must square the value from Step 3 and divide by the effective bandwidth EBW. The effective bandwidth depends upon which MFR Band (1 through 3) is being used (See Section 10.3.3).

Effective Bandwidth in Hz

MFR Band 1	5.6

MFR Band 2	19.4

MFR Band 3	139

The spectral density of the signal on the Ex dipole antenna is represented by Exdeltasd, the Ex+ monopole antenna by +Exsd and the Ex- antenna by -Exsd. The following equations show the method for calculating the electric antenna spectral density on the antennas in volts rms squared per hertz.

Exdeltasd	=	(VMExdelta)2 / EBW

+Exsd	=	(VM+Ex)2 / EBW

-Exsd	=	(VM-Ex)2 / EBW

Ezsd	=	(VMEz)2 / EBW

The spectral density of the signal from the Bx sensor is represented by Bxd. The spectral density of the signal from the Bz sensor is represented by Bzd. The following equations show the method for calculating the magnetic spectral density at the magnetic sensors in nanotesla squared per hertz.

Bxd	=	NTBx2 / EBW

Bzd	=	NTBz2 / EBW

Table 10.2.1.1

Conversion Table for Cassini Search Coil Bx (MFR)

MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT	MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT	MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT
1	1	23.89	0.0922	2	1	192.11	0.1505	3	1	1536.89	0.1466
1	2	26.25	0.0973	2	2	214.63	0.1506	3	2	1671.81	0.1464
1	3	29.15	0.1030	2	3	225.98	0.1505	3	3	1785.10	0.1463
1	4	32.42	0.1088	2	4	237.40	0.1504	3	4	1899.17	0.1462
1	5	36.27	0.1149	2	5	260.42	0.1503	3	5	2083.33	0.1459
1	6	40.89	0.1215	2	6	272.02	0.1502	3	6	2269.55	0.1456
1	7	46.51	0.1285	2	7	295.43	0.1501	3	7	2316.43	0.1455
1	8	52.82	0.1340	2	8	307.23	0.1500	3	8	2481.55	0.1452
1	9	60.43	0.1379	2	9	331.04	0.1499	3	9	2648.30	0.1450
1	10	69.46	0.1420	2	10	355.11	0.1498	3	10	2816.71	0.1447
1	11	80.05	0.1444	2	11	379.46	0.1497	3	11	3011.24	0.1445
1	12	92.34	0.1468	2	12	404.09	0.1496	3	12	3208.00	0.1443
1	13	107.24	0.1483	2	13	429.01	0.1495	3	13	3432.08	0.1440
1	14	124.39	0.1489	2	14	454.22	0.1494	3	14	3659.09	0.1437
1	15	144.88	0.1495	2	15	492.58	0.1493	3	15	3992.29	0.1434
1	16	169.05	0.1500	2	16	518.53	0.1492	3	16	4279.24	0.1432
2	17	558.04	0.1490	3	17	4651.27	0.1428
2	18	598.25	0.1488	3	18	4813.11	0.1427
2	19	639.20	0.1487	3	19	5086.11	0.1424
2	20	680.91	0.1485	3	20	5419.21	0.1419
2	21	723.38	0.1483	3	21	5758.48	0.1415
2	22	766.65	0.1482	3	22	6162.32	0.1409
2	23	825.61	0.1479	3	23	6575.06	0.1404
2	24	870.82	0.1478	3	24	7027.51	0.1399
2	25	932.46	0.1476	3	25	7490.92	0.1388
2	26	995.71	0.1474	3	26	7997.75	0.1377
2	27	1060.64	0.1473	3	27	8518.02	0.1366
2	28	1144.25	0.1471	3	28	9120.06	0.1354
2	29	1213.20	0.1470	3	29	9705.63	0.1343
2	30	1302.08	0.1469	3	30	10165.01	0.1325
2	31	1375.44	0.1468	3	31	11078.04	0.1255
2	32	1470.09	0.1466	3	32	11799.33	0.1204

Table 10.2.1.2

Conversion Table for Cassini Search Coil Bz (MFR)

MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT	MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT	MFR

Band	MFR

Step	Center

Freq.	CFbx

V/nT
1	1	23.89	0.0914	2	1	192.11	0.1495	3	1	1536.89	0.1455
1	2	26.25	0.0965	2	2	214.63	0.1495	3	2	1671.81	0.1453
1	3	29.15	0.1021	2	3	225.98	0.1494	3	3	1785.10	0.1452
1	4	32.42	0.1079	2	4	237.40	0.1493	3	4	1899.17	0.1450
1	5	36.27	0.1139	2	5	260.42	0.1492	3	5	2083.33	0.1447
1	6	40.89	0.1204	2	6	272.02	0.1491	3	6	2269.55	0.1443
1	7	46.51	0.1273	2	7	295.43	0.1490	3	7	2316.43	0.1442
1	8	52.82	0.1329	2	8	307.23	0.1489	3	8	2481.55	0.1439
1	9	60.43	0.1369	2	9	331.04	0.1488	3	9	2648.30	0.1436
1	10	69.46	0.1410	2	10	355.11	0.1487	3	10	2816.71	0.1433
1	11	80.05	0.1434	2	11	379.46	0.1485	3	11	3011.24	0.1430
1	12	92.34	0.1458	2	12	404.09	0.1484	3	12	3208.00	0.1428
1	13	107.24	0.1473	2	13	429.01	0.1483	3	13	3432.08	0.1425
1	14	124.39	0.1479	2	14	454.22	0.1482	3	14	3659.09	0.1422
1	15	144.88	0.1484	2	15	492.58	0.1481	3	15	3992.29	0.1418
1	16	169.05	0.1490	2	16	518.53	0.1480	3	16	4279.24	0.1415
2	17	558.04	0.1478	3	17	4651.27	0.1411
2	18	598.25	0.1476	3	18	4813.11	0.1409
2	19	639.20	0.1475	3	19	5086.11	0.1406
2	20	680.91	0.1473	3	20	5419.21	0.1400
2	21	723.38	0.1472	3	21	5758.48	0.1394
2	22	766.65	0.1471	3	22	6162.32	0.1387
2	23	825.61	0.1469	3	23	6575.06	0.1380
2	24	870.82	0.1468	3	24	7027.51	0.1373
2	25	932.46	0.1467	3	25	7490.92	0.1356
2	26	995.71	0.1466	3	26	7997.75	0.1338
2	27	1060.64	0.1464	3	27	8518.02	0.1321
2	28	1144.25	0.1462	3	28	9120.06	0.1303
2	29	1213.20	0.1461	3	29	9705.63	0.1286
2	30	1302.08	0.1459	3	30	10165.01	0.1266
2	31	1375.44	0.1458	3	31	11078.04	0.1203
2	32	1470.09	0.1456	3	32	11799.33	0.1156
10.2.2 Examples of Conversions from Data Numbers to Science Units

Three examples of conversions from data numbers to science units will be performed. Examples will include the Ex+ dipole electric antennas, the Ex+ monopole electric antenna and the Bx Search Coil as sensor inputs.

1)	The first example will use the Ex+ dipole as the sensor input. For this example a data number of 97 for MFR Band 3 Step 18 will be converted to Vrms2 / (meter2 * Hz). The first step is to use the look up tables in Section 10.3.1 and find the table for MFR Band 3 Step 18. In this table the value of 2.7967E-05 Vrms corresponds to a data number of 97. Therefore Vtable is 2.7967E-05 Vrms. Since the tables were produced from Ex dipole calibration tests VDEx is equal to Vtable. Next VDEx is divided by the effective length of the Ex dipole antenna (Lexdelta) to obtain the electric field, VMExdelta, in Vrms / meter (see Section 10.2.1, Step 3).

VMExdelta	=	(VDEx) / (Lexdelta)

=	2.7967E-05 Vrms / 8.66 meters

=	3.2294E-06 Vrms / meter

VMExdelta is now squared and divided by the effective bandwidth of MFR Band 3 of 139 Hz to obtain the spectral density of the signal on the Ex dipole antenna (see Section 10.2.1, Step 4).

Spectral density on the Ex dipole	=	Exdelta = (VMExdelta)2 / EBWBand 3

=	(3.2294E-06 Vrms / meter)2 / 139 Hz

=	7.5029E-14 Vrms2 / (meters2 * Hz)

2)	The next example uses the Ex+ monopole electrical antenna as the sensor input. For this example MFR Band 2 Step 7 with a data number of 140 was chosen. The first step is to use the MFR Band 2 Step 7 look up table in Section 10.3.1. A data number of 140 corresponds to 1.3573E-04 Vrms. Referring to Step 2 of Section 10.2.1 Vtable is multiplied by (CF+ex) to give the voltage on the Ex+ monopole antenna.

VEx+	=	(CF+ex) * Vtable

=	1.0 * 1.3573e-04 Vrms

=	1.3573E-04 Vrms

VEx+ is now divided by the effective length of the Ex+ monopole (L+Ex) which is 5.0 meters (see Section 10.2.1, Step 3).

(VM+Ex)	=	(VEx+) / (L+Ex) = 1.3573E-04 Vrms / 5.0 meters

=	2.7146E-05 Vrms / meter

VM+Ex is now squared and divided by the effective bandwidth of MFR Band 2 of 19.4 Hz to obtain the spectral density of the signal on the Ex+ monopole antenna (see Section 10.2.1,

Step 4).

Spectral density on the Ex+ monopole	=	+Exsd = (VM+Ex)2 / EBW Band 2

=	(2.7146E-05)2 / 19.4 Hz

=	3.785E-11Vrms / (meter2 * Hz)

3)	The last example will use the Bx Search Coil as the sensor input. For this example MFR Band 1 Step 12 with a data number of 125 was chosen. The first step is to use the MFR Band 1 Step 12 look up table in Section 10.3.1. A data number of 125 corresponds to 1.7153E-04 Vrms. Referring to Step 2 of Section 10.2.1, Vtable is multiplied by CFbx to give the voltage, Vbxpa, at the output of the Bx Search Coil.

Vbxpa	=	(CFbx) * (Vtable) = 24.0 * 1.7153E-04

=	4.1167E-03 Vrms

Next the voltage at the output of the Bx Search Coil is converted to nT by dividing it by the conversion factor CBxnt in Table 10.2.1.1 for MFR Band 1 Step 12 (see Section 10.2.1, Step 3).

NTBx	=	Vbxpa / Cbxnt

=	4.1167E-03 Vrms / 0.1468 V / nT

=	2.8043E-02 nTrms

NTBx is now squared and divided by the effective bandwidth of MFR Band 1 of 5.6 Hz to obtain the spectral density of the magnetic field at the Bx Search Coil (see Section 10.2.1, Step 4).

Spectral density at the Bx Search Coil	=	Bxd

=	(NTBx)2 / EBWBand 1

=	(2.8043E-02 nT)2 / 5.6 Hz

=	5.077E-03 nTrms2 / Hz

10.3.1	Amplitude Calibration (Input Voltage Versus Output Data Numbers)

This section contains the amplitude calibration of the MFR steps. The tables in this section contain the relationships between the 8-bit data numbers at the output of the log compressors and the voltage at the Ex preamplifier inputs, VDEx. Differential signals of known amplitude are applied to the Ex+ and Ex- preamplifier inputs. The drive frequency is a step near the middle of each of the three MFR bands. The steps used for the MFR bands are MFR Band 1 Step 8, MFR Band 2 Step 16 and MFR Band 3 Step 10. An adjustable attenuator and a balancing transformer with a 1:1 turns ratio are placed between the oscillator and the Ex+ and Ex- preamplifier inputs. The stimulus amplitude is adjusted in 2 dB steps from 0 dBv (dB relative to 1 V-rms.) to -140 dBv. The oscillator level is switched from 1 V-rms. to 0.01 V-rms. when the output of the stimulus is stepped from to -118 dBv to -120 dBv. The stimulus set up for the amplitude calibration is shown in Figure 10.3.1.1.

All compressors have some degree of ripple in their amplitude response and averaging is necessary. Four or more measurements are taken for each amplitude setting and these are averaged arithmetically. The averaged output data numbers are then plotted as a function of dBv and linear fits between points are used in order to associate an input voltage with each possible data number from 0 to 255.

A correction is made to each curve to take into account that the signal input to the log compressor actually consists of both the applied signal and the noise floor. This noise is made up of preamplifier noise, noise external to the instrument, and the receiver noise. This correction may be expressed as follows:

V(t) 2 = V(n) 2 + V(s) 2	Equation 10.3.1.1

V(t) is the total signal at the input to the compressor. V(n) is the background noise and V(s) is the input signal. For most of the compressors, the noise level in the system is such that none of the compressor stages are saturated with no input signal present and a straight line fit provides a value for V(n). Calibrations are run in 2 dB steps below -100 dBv for each step. From this data steps are chosen such that they are not saturating the compressor.

The result of the above process, for each MFR step, is a look up table relating input voltage to the output data number. For amplitudes higher than the saturation level of the compressor, the lookup tables are obtained by adjusting the center step 2 dB calibrations up or down using the Channel-to-Channel gain results (see Section 10.3.2). For lower amplitudes, the least squares linear fit is performed for each step. The results are presented in tabular form and in graphical form for each step, and are shown in the MFR Appendix.

10.3.2	Channel-to-Channel Gains

The sensitivity of the MFR varies from step to step across the band. Variations of insertion losses and roll-off within MFR bands affect the calibrations of the steps of that band. The channel to channel gains were performed by stimulating the MFR with random noise at a fixed amplitude. If, for instance, a channel has a gain of +1dB relative to a reference channel, then the input signal of that channel is 1dB less than the reference channel input for the same output. The relative variations in random noise amplitude response were used to correct the sine wave look-up tables in Section 10.3.1. MFR Band 1 Step 8, MFR Band 2 Step 16 and MFR Band 3 Step 10 were used as the reference channels for this technique. This method adjusts for differences in the logarithmic section of the curves. The lower ends of the tables are filled in using the linear fit technique described in Section 10.3.1. The stimulus setup for the channel-to-channel gain test is shown in Figure 10.3.2.1.

The channel to channel gain test was performed using a random noise input signal. The random noise test data has interference at 60 Hz and at the 3rd, 5th and 7th harmonics of 60 Hz. This interference has been corrected for by interpolating or extrapolating from adjacent channels. The effective bandwidth calculations in Section 10.3.3 provide the correction factor between the random noise input and the sine wave input. This is because a known spectral density random noise input is used to calculate the effective bandwidth. Refer to Section 10.3.3 for details.

The corrected and uncorrected channel-to-channel gains for the MFR are presented in tabular and graphical formats in Tables 10.3.2.1 and 10.3.2.2 and Figures 10.3.2.2 and 10.3.2.3.

Table 10.3.2.2 MFR Corrected Chan-Chan Gain Data

Frequency

(Hz)	Output

(DN)	Frequency

(Hz)	Output

(DN)
2.3400E+01	1.3998E+02	9.4050E+02	1.8429E+02
2.5800E+01	1.4118E+02	1.0037E+03	1.8439E+02
2.8600E+01	1.4189E+02	1.0686E+03	1.8514E+02
3.1900E+01	1.4281E+02	1.1522E+03	1.8517E+02
3.5800E+01	1.4289E+02	1.2212E+03	1.8457E+02
4.0900E+01	1.4537E+02	1.3101E+03	1.8538E+02
4.6000E+01	1.4589E+02	1.3834E+03	1.8397E+02
5.2300E+01	1.4657E+02	1.4781E+03	1.8100E+02
5.9900E+01	1.4749E+02	1.5819E+03	1.9484E+02
6.9000E+01	1.4860E+02	1.7168E+03	1.9510E+02
7.9500E+01	1.4821E+02	1.8301E+03	1.9550E+02
9.1800E+01	1.4835E+02	1.9442E+03	1.9591E+02
1.0670E+02	1.5167E+02	2.1283E+03	1.9673E+02
1.2390E+02	1.5406E+02	2.3146E+03	1.9752E+02
1.4440E+02	1.5350E+02	2.3614E+03	1.9778E+02
1.6850E+02	1.5445E+02	2.5266E+03	1.9840E+02
2.0010E+02	1.8500E+02	2.6933E+03	1.9923E+02
2.2260E+02	1.8498E+02	2.8617E+03	1.9913E+02
2.3390E+02	1.8434E+02	3.0562E+03	1.9994E+02
2.4540E+02	1.8296E+02	3.2530E+03	1.9935E+02
2.6840E+02	1.8263E+02	3.4771E+03	1.9986E+02
2.8000E+02	1.8251E+02	3.7041E+03	2.0023E+02
3.0340E+02	1.8267E+02	4.0373E+03	2.0037E+02
3.1520E+02	1.8274E+02	4.3242E+03	2.0067E+02
3.3900E+02	1.8290E+02	4.6963E+03	2.0140E+02
3.6310E+02	1.8294E+02	4.8581E+03	2.0140E+02
3.8740E+02	1.8203E+02	5.1311E+03	2.0159E+02
4.1200E+02	1.8225E+02	5.4642E+03	2.0181E+02
4.3700E+02	1.8184E+02	5.8035E+03	2.0257E+02
4.6220E+02	1.8143E+02	6.2073E+03	2.0254E+02
5.0050E+02	1.8256E+02	6.6201E+03	2.0286E+02
5.2650E+02	1.8275E+02	7.0725E+03	2.0307E+02
5.6600E+02	1.8253E+02	7.5359E+03	2.0326E+02
6.0630E+02	1.8361E+02	8.0427E+03	2.0357E+02
6.4720E+02	1.8364E+02	8.5630E+03	2.0338E+02
6.8890E+02	1.8355E+02	9.1651E+03	2.0396E+02
7.3180E+02	1.8302E+02	9.7506E+03	2.0340E+02
7.7460E+02	1.8319E+02	1.0210E+04	2.0402E+02
8.3360E+02	1.8476E+02	1.1123E+04	2.0307E+02
8.7880E+02	1.8496E+02	1.1844E+04	2.0164E+02

Table 10.3.2.1 MFR Uncorrected Chan-Chan Gain Data

Frequency

(Hz)	Output

(DN)	Frequency

(Hz)	Output

(DN)
2.3400E+01	1.3998E+02	9.4050E+02	1.8429E+02
2.5800E+01	1.4118E+02	1.0037E+03	1.8439E+02
2.8600E+01	1.4189E+02	1.0686E+03	1.8514E+02
3.1900E+01	1.4281E+02	1.1522E+03	1.8517E+02
3.5800E+01	1.4289E+02	1.2212E+03	1.8457E+02
4.0900E+01	1.4537E+02	1.3101E+03	1.8538E+02
4.6000E+01	1.4589E+02	1.3834E+03	1.8397E+02
5.2300E+01	1.5145E+02	1.4781E+03	1.8100E+02
5.9900E+01	1.6401E+02	1.5819E+03	1.9484E+02
6.9000E+01	1.4860E+02	1.7168E+03	1.9510E+02
7.9500E+01	1.4821E+02	1.8301E+03	1.9550E+02
9.1800E+01	1.4835E+02	1.9442E+03	1.9591E+02
1.0670E+02	1.5167E+02	2.1283E+03	1.9673E+02
1.2390E+02	1.5406E+02	2.3146E+03	1.9752E+02
1.4440E+02	1.5350E+02	2.3614E+03	1.9778E+02
1.6850E+02	1.5445E+02	2.5266E+03	1.9840E+02
2.0010E+02	1.9767E+02	2.6933E+03	1.9923E+02
2.2260E+02	1.8498E+02	2.8617E+03	1.9913E+02
2.3390E+02	1.8434E+02	3.0562E+03	1.9994E+02
2.4540E+02	1.8296E+02	3.2530E+03	1.9935E+02
2.6840E+02	1.8263E+02	3.4771E+03	1.9986E+02
2.8000E+02	1.8251E+02	3.7041E+03	2.0023E+02
3.0340E+02	1.8490E+02	4.0373E+03	2.0037E+02
3.1520E+02	1.8684E+02	4.3242E+03	2.0067E+02
3.3900E+02	1.8290E+02	4.6963E+03	2.0140E+02
3.6310E+02	1.8294E+02	4.8581E+03	2.0140E+02
3.8740E+02	1.8203E+02	5.1311E+03	2.0159E+02
4.1200E+02	1.8225E+02	5.4642E+03	2.0181E+02
4.3700E+02	1.8465E+02	5.8035E+03	2.0257E+02
4.6220E+02	1.8143E+02	6.2073E+03	2.0254E+02
5.0050E+02	1.8256E+02	6.6201E+03	2.0286E+02
5.2650E+02	1.8275E+02	7.0725E+03	2.0307E+02
5.6600E+02	1.8253E+02	7.5359E+03	2.0326E+02
6.0630E+02	1.8361E+02	8.0427E+03	2.0357E+02
6.4720E+02	1.8364E+02	8.5630E+03	2.0338E+02
6.8890E+02	1.8355E+02	9.1651E+03	2.0396E+02
7.3180E+02	1.8302E+02	9.7506E+03	2.0340E+02
7.7460E+02	1.8319E+02	1.0210E+04	2.0402E+02
8.3360E+02	1.8476E+02	1.1123E+04	2.0307E+02
8.7880E+02	1.8496E+02	1.1844E+04	2.0164E+02

10.3.3	Effective Noise Bandwidth

In this section the detection bandwidth calibration data for the MFR is presented. There are two ways to evaluate detection bandwidth. One is to measure the frequency response of the filter. A sinusoidal stimulus is swept over the filter pass-band and the response of the compressor is noted. The other method is to determine the effective bandwidth by noting the compressor response to a white noise stimulus. In the following paragraphs, both methods are discussed and filter data are presented for the MFR filters

10.3.3.1	Filter Frequency Response Curves

The sine wave frequency responses of the detection filters used in the MFR are determined by applying a differential signal fixed at 0.001 volts rms to the Ex inputs and sweeping it over the filter pass-bands. Figures 10.3.3.1.1, 10.3.3.1.2 and 10.3.3.1.3 show the curves for Band 1 Step 8, Band 2 Step16, and Band 3 Step 10, respectively, using the Ex inputs. The data is also given in tabular form in Tables 10.3.3.1.1 through 10.3.3.1.3. The MFR plots show the upper and the lower side bands. The MFR Band 1 circuit is designed to reject the lower side band. The responses for any MFR step other than the center steps are determined by making an adjustment according to the channel-to-channel gain tables presented in Section 10.3.2 of this document. The response for sensors other than the Ex+ and Ex- is determined by referring to the differential amplifier calibrations and the sensor calibrations in Sections 6.0 and 7.0 of this document to determine an appropriate factor to adjust the amplitude by. The stimulus setup is shown in Figure 10.3.3.1.4.

10.3.3.2	Effective Bandwidths

The frequency response curves shown in Section 10.3.3.1 were generated with sine wave stimuli. While this is useful for observing the filter shape and estimating the bandwidth, many actual emissions more closely approximate random noise having bandwidths wide in comparison to the filter bandwidth. It is necessary to be able to interpret the amplitude measurements in terms of the noise spectral density of the received signal. To determine the spectral density Vf2 the following equation is used:

Vf2 = Vs2/Df	Equation 10.3.3.2.1

For a given output data number, the look-up tables in Section 10.3.1 can be used to find the corresponding input voltage Vs. The effective bandwidth Df is defined to be the bandwidth which Vs2 must be divided by to give the input voltage spectral density if the same log compressor output voltage were due entirely to a random noise input. Note that this effective bandwidth includes the effects of both the filter bandwidth and the non-ideal detection characteristics of the log compressor. If the compressor were a true rms detector (square-law device) then the effective bandwidth defined in equation 10.3.3.2.1 would be equivalent to the well-known 'noise-bandwidth' commonly used to characterize the bandwidth of a filter. The effective bandwidth Df cannot be interpreted as the 'noise bandwidth' in the usual sense.

The noise bandwidth of each of the three MFR bands was determined in the following manner. A random noise signal of known density was applied to the MFR. The density was calculated by measuring the random noise amplitude before the step attenuators with a spectrum analyzer. Several readings were averaged together to improve the accuracy of the measurement. The test setup for determining the effective bandwidths of the MFR filters consists of a random noise generator with a white spectrum over the frequency range of the filters. Figures 10.3.3.2.1, 10.3.3.2.2, and 10.3.3.2.3 show the stimulus set ups used to determine the effective bandwidths. Different setups are used depending on the noise frequency range. In every case, a white noise stimulus of known power spectral density is injected into the programmable attenuator. The differential signal is applied to the Ex+ and Ex- inputs. A 2-dB calibration was performed using white noise. Large amplitude noise inputs which saturated the receiver and low level inputs at the receiver noise level were discarded. Both of these cause error in bandwidth calculation. For each amplitude number corresponding to a given spectral density, the program finds a value out of a file containing 2-dB calibration values. A computation is performed according to the expression in Equation 10.3.3.2.1 to determine the effective bandwidth. Several bandwidths, corresponding to various input noise densities, were averaged together.

Tables 10.3.3.2.1, 10.3.3.2.2, and 10.3.3.2.3 consists of 3 tables for the MFR effective bandwidths. These were calculated for the center step of each band of the MFR in logarithmic mode. The effective bandwidths are constant for any step on a given band because the same detection filters and log compressors area used in that band.

Table 10.3.3.1.1 MFR Band 1 Normalized Frequency Response

Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)
22.3000	0.0060	52.3000	1.0000
23.3000	0.0063	53.3000	1.0000
24.3000	0.0065	54.3000	0.9551
25.3000	0.0071	55.3000	0.8427
26.3000	0.0079	56.3000	0.8023
27.3000	0.0083	57.3000	0.7074
28.3000	0.0089	58.3000	0.6113
29.3000	0.0099	59.3000	0.4983
30.3000	0.0108	60.3000	0.4247
31.3000	0.0115	61.3000	0.3443
32.3000	0.0115	62.3000	0.2993
33.3000	0.0125	63.3000	0.2551
34.3000	0.0097	64.3000	0.2145
35.3000	0.0075	65.3000	0.1777
36.3000	0.0042	66.3000	0.1518
37.3000	0.0024	67.3000	0.1254
38.3000	0.0019	68.3000	0.1025
39.3000	0.0017	69.3000	0.0830
40.3000	0.0018	70.3000	0.0721
41.3000	0.0020	71.3000	0.0560
42.3000	0.0023	72.3000	0.0455
43.3000	0.0024	73.3000	0.0352
44.3000	0.0030	74.3000	0.0275
45.3000	0.0148	75.3000	0.0219
46.3000	0.0374	76.3000	0.0172
47.3000	0.1139	77.3000	0.0125
48.3000	0.2551	78.3000	0.0093
49.3000	0.4689	79.3000	0.0069
50.3000	0.7382	80.3000	0.0051
51.3000	0.9325	81.3000	0.0033

Table 10.3.3.1.2 MFR Band 2 Normalized Frequency Response

Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)
451.5000	0.0022	481.5000	0.0054	511.5000	0.9602	541.5000	0.0306	571.5000	0.0008
452.5000	0.0020	482.5000	0.0077	512.5000	0.9205	542.5000	0.0247	572.5000	0.0006
453.5000	0.0056	483.5000	0.0081	513.5000	0.8146	543.5000	0.0160	573.5000	0.0006
454.5000	0.0024	484.5000	0.0085	514.5000	0.6331	544.5000	0.0112	574.5000	0.0007
455.5000	0.0040	485.5000	0.0076	515.5000	0.4450	545.5000	0.0088	575.5000	0.0005
456.5000	0.0044	486.5000	0.0095	516.5000	0.2304	546.5000	0.0072	576.5000	0.0005
457.5000	0.0012	487.5000	0.0085	517.5000	0.0654	547.5000	0.0059	577.5000	0.0005
458.5000	0.0017	488.5000	0.0104	518.5000	0.0221	548.5000	0.0041	578.5000	0.0006
459.5000	0.0011	489.5000	0.0118	519.5000	0.0634	549.5000	0.0032	579.5000	0.0006
460.5000	0.0013	490.5000	0.0175	520.5000	0.1648	550.5000	0.0025	580.5000	0.0006
461.5000	0.0009	491.5000	0.0194	521.5000	0.3927	551.5000	0.0020	581.5000	0.0006
462.5000	0.0012	492.5000	0.0228	522.5000	0.6106	552.5000	0.0016	582.5000	0.0005
463.5000	0.0010	493.5000	0.0215	523.5000	0.6448	553.5000	0.0013	583.5000	0.0005
464.5000	0.0011	494.5000	0.0365	524.5000	0.8016	554.5000	0.0012	584.5000	0.0007
465.5000	0.0016	495.5000	0.0510	525.5000	0.7349	555.5000	0.0011	585.5000	0.0005
466.5000	0.0025	496.5000	0.0634	526.5000	0.8016	556.5000	0.0009	586.5000	0.0006
467.5000	0.0026	497.5000	0.0883	527.5000	0.7530	557.5000	0.0007	587.5000	0.0006
468.5000	0.0019	498.5000	0.1139	528.5000	0.7470	558.5000	0.0008	588.5000	0.0005
469.5000	0.0013	499.5000	0.1859	529.5000	0.7108	559.5000	0.0010	589.5000	0.0005
470.5000	0.0041	500.5000	0.2840	530.5000	0.6568	560.5000	0.0007	590.5000	0.0006
471.5000	0.0025	501.5000	0.4581	531.5000	0.6331	561.5000	0.0008	591.5000	0.0005
472.5000	0.0023	502.5000	0.5548	532.5000	0.5548	562.5000	0.0006	592.5000	0.0005
473.5000	0.0019	503.5000	0.6568	533.5000	0.4716	563.5000	0.0008	593.5000	0.0004
474.5000	0.0046	504.5000	0.7530	534.5000	0.3686	564.5000	0.0008	594.5000	0.0004
475.5000	0.0023	505.5000	0.8542	535.5000	0.2572	565.5000	0.0006	595.5000	0.0005
476.5000	0.0029	506.5000	0.8807	536.5000	0.1930	566.5000	0.0006	596.5000	0.0005
477.5000	0.0038	507.5000	0.9205	537.5000	0.1228	567.5000	0.0006	597.5000	0.0005
478.5000	0.0067	508.5000	0.9205	538.5000	0.0897	568.5000	0.0007	598.5000	0.0006
479.5000	0.0061	509.5000	0.9867	539.5000	0.0622	569.5000	0.0006	599.5000	0.0006
480.5000	0.0041	510.5000	1.0000	540.5000	0.0452	570.5000	0.0006	600.5000	0.0005

Table 10.3.3.1.3 MFR Band 3 Normalized Frequency Response

Frequency

(Hz)	Amplitude

(normalized)	Frequency

(Hz)	Amplitude

(normalized)
2461.7000	0.0023	2861.7000	0.9011
2471.7000	0.0034	2871.7000	0.8505
2481.7000	0.0075	2881.7000	0.8168
2491.7000	0.0036	2891.7000	0.7663
2501.7000	0.0019	2901.7000	0.6771
2511.7000	0.0016	2911.7000	0.5350
2521.7000	0.0017	2921.7000	0.4513
2531.7000	0.0017	2931.7000	0.3079
2541.7000	0.0021	2941.7000	0.1864
2551.7000	0.0022	2951.7000	0.1096
2561.7000	0.0019	2961.7000	0.0656
2571.7000	0.0019	2971.7000	0.0367
2581.7000	0.0031	2981.7000	0.0237
2591.7000	0.0033	2991.7000	0.0142
2601.7000	0.0038	3001.7000	0.0093
2611.7000	0.0055	3011.7000	0.0060
2621.7000	0.0075	3021.7000	0.0040
2631.7000	0.0122	3031.7000	0.0031
2641.7000	0.0203	3041.7000	0.0024
2651.7000	0.0260	3051.7000	0.0019
2661.7000	0.0409	3061.7000	0.0015
2671.7000	0.0814	3071.7000	0.0013
2681.7000	0.1281	3081.7000	0.0013
2691.7000	0.2186	3091.7000	0.0012
2701.7000	0.3854	3101.7000	0.0012
2711.7000	0.5917	3111.7000	0.0010
2721.7000	0.7308	3121.7000	0.0009
2731.7000	0.8842	3131.7000	0.0010
2741.7000	0.9349	3141.7000	0.0010
2751.7000	1.0000	3151.7000	0.0010
2761.7000	1.0000	3161.7000	0.0010
2771.7000	0.9865	3171.7000	0.0011
2781.7000	0.9602	3181.7000	0.0011
2791.7000	0.9349	3191.7000	0.0012
2801.7000	0.8000	3201.7000	0.0012
2811.7000	0.3044	3211.7000	0.0009
2821.7000	0.3451	3221.7000	0.0011
2831.7000	0.7663	3231.7000	0.0010
2841.7000	0.8337	3241.7000	0.0009
2851.7000	0.8505	3251.7000	0.0012

Table 10.3.3.2.1 MFR Band 1 Noise Bandwidth Calculation

Attenuation

(dB)	Noise

Bandwidth

(Hz)
40.00000	3.95021
42.00000	4.71771
44.00000	5.44352
46.00000	5.45427
48.00000	4.80216
50.00000	5.57220
52.00000	5.03907
54.00000	7.46237
56.00000	7.67222
58.00000	7.13399
60.00000	5.28326
62.00000	5.48081
64.00000	5.67438
66.00000	4.45331
68.00000	5.30630
70.00000	5.45724
72.00000	7.46054
74.00000	5.65557
76.00000	5.89967
78.00000	6.08212
80.00000	4.84844

Average Noise Bandwidth = 5.65949 Hz

Table 10.3.3.2.2 MFR Band 2 Noise Bandwidth Calculations

Attenuation

(dB)	Noise

Bandwidth

(Hz)
40.00000	23.16115
42.00000	18.32768
44.00000	20.09491
46.00000	30.10968
48.00000	19.30607
50.00000	19.76923
52.00000	19.63375
54.00000	15.33376
56.00000	12.49454
58.00000	17.21832
60.00000	25.28433
62.00000	20.03923
64.00000	28.66408
66.00000	26.96831
68.00000	18.16952
70.00000	17.46194
72.00000	11.97135
74.00000	16.02716
76.00000	15.62077
78.00000	13.97217
80.00000	17.90250

Average Noise Bandwidth = 19.40621 Hz

Table 10.3.3.2.3 MFR Band 3 Noise Bandwidth Calculation

Attenuation

(dB)	Noise

Bandwidth

(Hz)
40.00000	126.94929
42.00000	150.54008
44.00000	117.92113
46.00000	167.13432
48.00000	170.56709
50.00000	165.75240
52.00000	183.88214
54.00000	183.68256
56.00000	168.28555
58.00000	116.19930
60.00000	104.42429
62.00000	120.06332
64.00000	123.04401
66.00000	116.88811
68.00000	152.99593
70.00000	156.18509
72.00000	109.23030
74.00000	143.60846
76.00000	106.50285
78.00000	128.32590
80.00000	103.17294

Average Noise Bandwidth = 138.82643 Hz

10.3.4 Receiver Noise Levels

10.3.4.1 In-Flight Receiver Noise Levels

In-flight noise levels of the MFR were obtained during the deployment of the electric antennas on Oct. 24-25, 1997. The noise levels were measured both with the antennas retracted, before the extension of the antennas, and after the antennas were extended. The noise levels were determined by looking for the data number with the peak number of occurrences in each channel. These peak data numbers were then converted into voltage from the amplitude tables in Section 10.3.1. The square of the voltage of each step was then divided by the effective noise bandwidth of the respective band. This noise level data is listed in Tables 10.3.4.1.1 and 10.3.4.1.2 and shown in Figures 10.3.4.1.1 and 10.3.4.1.2.

In-flight noise levels were also measured after the antennas were extended. The noise levels were also determined by looking for the data number with the peak number of occurrences in each channel. This was done during the time after the antennas were extended and when not in direction finding mode. The number of occurrences of data numbers would increase with increasing data number values. A peak number of occurrences would be reached and then the number of occurrences would decrease. The noise level is assumed to be at this peak. This is because the signals at the input to the receiver will be at the noise levels the greatest amount of time. Real signals will stay at constant levels for much less time then at the noise level. On some channels a second peak occurred greater than the first peak. The first peak was chosen as the noise level and the other peaks to be time dependent interference signals. There are times that the in-flight data is below the noise level. Data numbers below the measured noise level are handled by extending the calibration curves. The extended noise level data is listed in Tables 10.3.4.1.3 and 10.3.4.1.4 and shown in Figures 10.3.4.1.3 and 10.3.4.1.4.

The in-flight search coil noise levels were performed in the same manner as the electric antenna. The results are shown in Tables 10.3.4.1.5 and 10.3.4.1.6 and Figures 10.3.4.1.5 and 10.3.4.1.6.

10.3.4.2 Bench Level Receiver Noise Levels (Pre-flight)

A series of tests were performed on the ground before launch to determine the instrument noise level with a variety of loads across the inputs of the instrument. Figure 10.3.4.2.1 and Table 10.3.4.2.1 show the measured noise level of the MFR with a 220 pF capacitor across the input to the Ex antenna input. Figure 10.3.4.2.2 and Table 10.3.4.2.2 show the measured noise level of the MFR with a 220 pF capacitor in parallel with a 10 M resistor across the input to the Ex antenna input. Figure 10.3.4.2.3 and Table 10.3.4.2.3 show the measured noise level of the MFR attached to the Bx search coil. The large signals observed at 60 Hz (and harmonics) is due to power line interference.

Table 10.3.4.1.1 MFR In-Flight ExLo Noise Plot (Antennas Retracted)

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	1.1354e-10	41	940.50	6.0518e-15
2	25.80	4.0518e-11	42	1003.70	7.9681e-15
3	28.60	1.0558e-11	43	1068.60	7.7984e-15
4	31.90	6.6563e-12	44	1152.20	4.5675e-15
5	35.80	1.2472e-11	45	1221.20	5.5245e-15
6	40.90	1.2282e-11	46	1310.10	5.8439e-15
7	46.00	2.4400e-12	47	1383.40	3.5243e-15
8	52.30	6.6600e-12	48	1478.10	6.6346e-15
9	59.90	1.8689e-12	49	1581.90	7.7708e-14
10	69.00	2.7574e-12	50	1716.80	1.3394e-14
11	79.50	1.1537e-12	51	1830.10	1.3780e-14
12	91.80	1.0451e-12	52	1944.20	3.3167e-14
13	106.70	9.7571e-13	53	2128.30	2.0104e-13
14	123.90	3.7530e-13	54	2314.60	6.5814e-14
15	144.40	3.6609e-13	55	2361.40	2.0190e-14
16	168.50	2.4586e-13	56	2526.60	1.1940e-14
17	200.10	1.8522e-13	57	2693.30	8.4237e-15
18	222.60	7.7150e-14	58	2861.70	1.6227e-14
19	233.90	5.0610e-14	59	3056.20	9.0051e-15
20	245.40	1.1206e-13	60	3253.00	1.1666e-14
21	268.40	1.0636e-13	61	3477.10	1.1336e-14
22	280.00	7.3057e-14	62	3704.10	6.4628e-15
23	303.40	5.8699e-14	63	4037.30	1.3433e-14
24	315.20	5.2347e-14	64	4324.20	4.5689e-14
25	339.00	3.2599e-14	65	4696.30	6.5666e-14
26	363.10	5.3664e-14	66	4858.10	2.8069e-14
27	387.40	3.3990e-14	67	5131.10	8.9071e-15
28	412.00	3.3388e-14	68	5464.20	9.2386e-15
29	437.00	2.8252e-14	69	5803.50	1.5816e-14
30	462.20	1.6498e-14	70	6207.30	1.0529e-14
31	500.50	1.4039e-14	71	6620.10	7.3684e-15
32	526.50	1.4177e-14	72	7072.50	3.2088e-14
33	566.00	1.0322e-14	73	7535.90	2.6560e-14
34	606.30	1.0136e-14	74	8042.70	7.8360e-15
35	647.20	1.0971e-14	75	8563.00	1.2326e-14
36	688.90	8.6330e-15	76	9165.10	8.2070e-15
37	731.80	2.4637e-14	77	9750.60	1.2938e-14
38	774.60	6.1046e-15	78	10210.00	4.7480e-14
39	833.60	9.1727e-15	79	11123.00	1.4294e-14
40	878.80	9.3085e-15	80	11844.00	8.5456e-15

Table 10.3.4.1.2 MFR In-Flight EzLo Noise Plot (Antennas Retracted)

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	6.4583e-10	41	940.50	1.2627e-14
2	25.80	2.8648e-10	42	1003.70	7.9681e-15
3	28.60	4.2874e-11	43	1068.60	4.9904e-15
4	31.90	7.3389e-11	44	1152.20	8.6352e-15
5	35.80	1.2401e-10	45	1221.20	1.0445e-14
6	40.90	1.4093e-10	46	1310.10	8.7299e-15
7	46.00	1.3709e-11	47	1383.40	1.4101e-14
8	52.30	7.6005e-11	48	1478.10	1.2543e-14
9	59.90	9.2187e-12	49	1581.90	1.0102e-13
10	69.00	4.3276e-11	50	1716.80	1.3394e-14
11	79.50	7.5904e-12	51	1830.10	1.3780e-14
12	91.80	3.6184e-12	52	1944.20	2.7152e-14
13	106.70	4.5976e-12	53	2128.30	8.0246e-14
14	123.90	1.8400e-12	54	2314.60	4.1397e-14
15	144.40	3.4570e-12	55	2361.40	8.0554e-15
16	168.50	2.3490e-12	56	2526.60	1.0400e-14
17	200.10	2.0960e-12	57	2693.30	7.2624e-15
18	222.60	5.6508e-13	58	2861.70	3.5095e-14
19	233.90	1.5850e-12	59	3056.20	9.0051e-15
20	245.40	1.3955e-12	60	3253.00	1.3530e-14
21	268.40	3.1481e-13	61	3477.10	1.1336e-14
22	280.00	5.7636e-13	62	3704.10	5.5068e-15
23	303.40	1.8974e-13	63	4037.30	9.3285e-15
24	315.20	2.0410e-13	64	4324.20	2.9719e-14
25	339.00	4.5115e-13	65	4696.30	1.1051e-14
26	363.10	1.1650e-13	66	4858.10	1.0962e-14
27	387.40	1.1679e-13	67	5131.10	6.6896e-15
28	412.00	8.8877e-14	68	5464.20	7.9658e-15
29	437.00	3.9839e-14	69	5803.50	1.5816e-14
30	462.20	6.5997e-14	70	6207.30	7.9083e-15
31	500.50	4.0209e-14	71	6620.10	8.4580e-15
32	526.50	4.8316e-14	72	7072.50	1.5384e-14
33	566.00	5.3318e-14	73	7535.90	2.0335e-14
34	606.30	4.4316e-14	74	8042.70	7.8360e-15
35	647.20	6.6102e-14	75	8563.00	1.0834e-14
36	688.90	5.3949e-14	76	9165.10	7.0762e-15
37	731.80	4.2132e-14	77	9750.60	8.7747e-15
38	774.60	2.7207e-14	78	10210.00	1.1117e-14
39	833.60	4.0454e-14	79	11123.00	1.1128e-14
40	878.80	1.9695e-14	80	11844.00	6.4191e-15

Table 10.3.4.1.3 MFR In-Flight ExLo Noise Plot (Antennas Extended)

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	4.0811e-10	41	940.50	3.1964e-13
2	25.80	6.0413e-10	42	1003.70	3.6061e-13
3	28.60	5.7717e-10	43	1068.60	3.1367e-13
4	31.90	1.2465e-10	44	1152.20	3.0997e-13
5	35.80	2.1238e-10	45	1221.20	1.9161e-13
6	40.90	3.8463e-11	46	1310.10	1.3314e-13
7	46.00	3.7212e-11	47	1383.40	1.5268e-13
8	52.30	3.5880e-11	48	1478.10	2.0488e-13
9	59.90	2.1751e-11	49	1581.90	3.7918e-13
10	69.00	3.2183e-11	50	1716.80	1.6659e-13
11	79.50	3.2811e-11	51	1830.10	2.1584e-13
12	91.80	1.9510e-11	52	1944.20	2.1997e-13
13	106.70	1.7957e-11	53	2128.30	3.9318e-13
14	123.90	1.1814e-11	54	2314.60	1.5625e-13
15	144.40	7.1360e-12	55	2361.40	9.2016e-14
16	168.50	7.1546e-12	56	2526.60	8.4904e-14
17	200.10	1.6191e-11	57	2693.30	7.3338e-14
18	222.60	5.9162e-12	58	2861.70	8.7134e-14
19	233.90	3.5466e-12	59	3056.20	5.6296e-14
20	245.40	3.9471e-12	60	3253.00	8.5563e-14
21	268.40	1.2268e-11	61	3477.10	7.1924e-14
22	280.00	3.2576e-12	62	3704.10	4.6846e-14
23	303.40	2.3336e-12	63	4037.30	5.0787e-14
24	315.20	2.4793e-12	64	4324.20	6.8657e-14
25	339.00	2.3636e-12	65	4696.30	6.9076e-14
26	363.10	2.5875e-12	66	4858.10	5.9693e-14
27	387.40	2.0027e-12	67	5131.10	3.8049e-14
28	412.00	2.4788e-12	68	5464.20	4.5291e-14
29	437.00	1.6639e-12	69	5803.50	4.2108e-14
30	462.20	1.6574e-12	70	6207.30	3.9354e-14
31	500.50	1.8739e-12	71	6620.10	3.6124e-14
32	526.50	1.7124e-12	72	7072.50	4.5620e-14
33	566.00	7.8100e-13	73	7535.90	3.8777e-14
34	606.30	9.6934e-13	74	8042.70	2.5386e-14
35	647.20	7.9098e-13	75	8563.00	3.5099e-14
36	688.90	7.5913e-13	76	9165.10	3.0526e-14
37	731.80	4.7622e-13	77	9750.60	3.2634e-14
38	774.60	4.3711e-13	78	10210.00	4.7480e-14
39	833.60	4.3101e-13	79	11123.00	3.0913e-14
40	878.80	3.7124e-13	80	11844.00	1.8380e-14

Table 10.3.4.1.4 MFR In-Flight EzLo Noise Plot (Antennas Extended)

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	1.3205e-09	41	940.50	1.7463e-13
2	25.80	8.5894e-10	42	1003.70	1.9572e-13
3	28.60	2.6828e-09	43	1068.60	3.1367e-13
4	31.90	1.8139e-09	44	1152.20	1.6479e-13
5	35.80	1.1104e-09	45	1221.20	1.5071e-13
6	40.90	6.1224e-10	46	1310.10	1.3314e-13
7	46.00	4.5507e-10	47	1383.40	1.3988e-13
8	52.30	5.2392e-10	48	1478.10	1.2315e-13
9	59.90	1.9753e-10	49	1581.90	2.9194e-13
10	69.00	1.5389e-10	50	1716.80	1.2008e-13
11	79.50	1.5702e-10	51	1830.10	1.8700e-13
12	91.80	4.8643e-11	52	1944.20	1.8434e-13
13	106.70	3.9302e-11	53	2128.30	2.2221e-13
14	123.90	1.5432e-11	54	2314.60	1.4127e-13
15	144.40	1.3529e-11	55	2361.40	1.2469e-13
16	168.50	5.9709e-12	56	2526.60	7.6628e-14
17	200.10	6.3376e-12	57	2693.30	6.8599e-14
18	222.60	5.9162e-12	58	2861.70	7.3605e-14
19	233.90	6.4063e-12	59	3056.20	8.2629e-14
20	245.40	6.0294e-12	60	3253.00	9.6107e-14
21	268.40	4.1584e-12	61	3477.10	1.0198e-13
22	280.00	4.1539e-12	62	3704.10	4.1646e-14
23	303.40	4.8131e-12	63	4037.30	5.0787e-14
24	315.20	2.0596e-12	64	4324.20	7.6183e-14
25	339.00	1.9877e-12	65	4696.30	8.0039e-14
26	363.10	2.0570e-12	66	4858.10	6.3150e-14
27	387.40	2.7209e-12	67	5131.10	6.8368e-14
28	412.00	1.3039e-12	68	5464.20	3.1860e-14
29	437.00	2.1406e-12	69	5803.50	5.6788e-14
30	462.20	1.1709e-12	70	6207.30	3.9354e-14
31	500.50	1.0805e-12	71	6620.10	5.1463e-14
32	526.50	7.8642e-13	72	7072.50	5.1694e-14
33	566.00	8.5808e-13	73	7535.90	4.4314e-14
34	606.30	3.9693e-13	74	8042.70	2.1763e-14
35	647.20	4.9760e-13	75	8563.00	5.5658e-14
36	688.90	6.3583e-13	76	9165.10	2.4120e-14
37	731.80	4.0019e-13	77	9750.60	4.8754e-14
38	774.60	4.3711e-13	78	10210.00	4.4467e-14
39	833.60	4.3101e-13	79	11123.00	2.8488e-14
40	878.80	2.1118e-13	80	11844.00	2.0092e-14

Table10.3.4.1.5 MFR In-Flight Bx Noise Plot

Channel	Frequency

(Hz)	nT2/Hz	Channel	Frequency

(Hz)	nT2/Hz
1	23.40	1.1523e-06	41	940.50	1.1378e-09
2	25.80	3.7454e-07	42	1003.70	9.4126e-10
3	28.60	3.1279e-07	43	1068.60	7.4746e-10
4	31.90	1.6671e-07	44	1152.20	6.8548e-10
5	35.80	3.0351e-07	45	1221.20	8.3044e-10
6	40.90	2.4326e-07	46	1310.10	6.9529e-10
7	46.00	1.0187e-07	47	1383.40	6.9429e-10
8	52.30	1.0431e-07	48	1478.10	6.2471e-10
9	59.90	5.6566e-08	49	1581.90	4.2049e-09
10	69.00	4.6870e-08	50	1716.80	1.0582e-09
11	79.50	2.3761e-08	51	1830.10	1.6004e-09
12	91.80	4.4587e-08	52	1944.20	1.9488e-09
13	106.70	4.0754e-08	53	2128.30	7.7664e-09
14	123.90	1.7959e-08	54	2314.60	2.6058e-09
15	144.40	1.7385e-08	55	2361.40	1.2799e-09
16	168.50	1.1700e-08	56	2526.60	1.3926e-09
17	200.10	4.7096e-09	57	2693.30	8.5861e-10
18	222.60	3.1502e-09	58	2861.70	1.4835e-09
19	233.90	1.6969e-09	59	3056.20	1.2182e-09
20	245.40	2.8536e-09	60	3253.00	1.8366e-09
21	268.40	3.0461e-09	61	3477.10	1.5443e-09
22	280.00	1.5111e-09	62	3704.10	1.0244e-09
23	303.40	1.5013e-09	63	4037.30	1.1157e-09
24	315.20	2.7097e-09	64	4324.20	2.1414e-09
25	339.00	1.8803e-09	65	4696.30	1.9501e-09
26	363.10	1.7432e-09	66	4858.10	1.6882e-09
27	387.40	1.3940e-09	67	5131.10	1.3772e-09
28	412.00	2.9860e-09	68	5464.20	1.6506e-09
29	437.00	1.0266e-09	69	5803.50	1.5448e-09
30	462.20	9.0919e-10	70	6207.30	1.8802e-09
31	500.50	1.2365e-09	71	6620.10	1.5853e-09
32	526.50	7.8362e-10	72	7072.50	2.2740e-09
33	566.00	1.2749e-09	73	7535.90	2.2504e-09
34	606.30	1.2549e-09	74	8042.70	1.7064e-09
35	647.20	8.5323e-10	75	8563.00	2.7488e-09
36	688.90	1.6440e-09	76	9165.10	2.5965e-09
37	731.80	2.7861e-09	77	9750.60	2.7908e-09
38	774.60	7.1390e-10	78	10210.00	3.4846e-09
39	833.60	8.7139e-10	79	11123.00	4.4883e-09
40	878.80	7.3234e-10	80	11844.00	4.3636e-09

Table 10.3.4.1.6 MFR In-Flight Bz Noise Plot

Channel	Frequency

(Hz)	nT2/Hz	Channel	Frequency

(Hz)	nT2/Hz
1	23.40	9.1277e-07	41	940.50	3.3804e-10
2	25.80	3.0419e-07	42	1003.70	5.9347e-10
3	28.60	4.6934e-07	43	1068.60	2.5353e-10
4	31.90	1.5834e-07	44	1152.20	6.9404e-10
5	35.80	9.8221e-08	45	1221.20	4.5673e-10
6	40.90	7.8757e-08	46	1310.10	2.3619e-10
7	46.00	2.1677e-08	47	1383.40	4.3871e-10
8	52.30	3.0336e-08	48	1478.10	3.4071e-10
9	59.90	2.2778e-08	49	1581.90	3.9897e-09
10	69.00	2.3534e-08	50	1716.80	9.8639e-10
11	79.50	8.0765e-09	51	1830.10	1.5070e-09
12	91.80	9.4981e-09	52	1944.20	1.5019e-09
13	106.70	1.0332e-08	53	2128.30	4.5017e-09
14	123.90	6.1034e-09	54	2314.60	1.3527e-09
15	144.40	5.9092e-09	55	2361.40	1.0469e-09
16	168.50	1.1862e-08	56	2526.60	9.9770e-10
17	200.10	3.7693e-09	57	2693.30	7.5012e-10
18	222.60	1.7545e-09	58	2861.70	1.2342e-09
19	233.90	1.3059e-09	59	3056.20	9.4287e-10
20	245.40	1.4832e-09	60	3253.00	1.3190e-09
21	268.40	1.8473e-09	61	3477.10	1.5776e-09
22	280.00	1.5335e-09	62	3704.10	9.8083e-10
23	303.40	9.2171e-10	63	4037.30	1.2936e-09
24	315.20	1.2534e-09	64	4324.20	2.0814e-09
25	339.00	9.4531e-10	65	4696.30	2.3160e-09
26	363.10	1.1752e-09	66	4858.10	1.7309e-09
27	387.40	1.3002e-09	67	5131.10	1.1086e-09
28	412.00	6.9871e-10	68	5464.20	1.5092e-09
29	437.00	1.6640e-09	69	5803.50	1.8866e-09
30	462.20	8.2904e-10	70	6207.30	1.9420e-09
31	500.50	9.6200e-10	71	6620.10	1.5559e-09
32	526.50	7.9638e-10	72	7072.50	2.1010e-09
33	566.00	4.4088e-10	73	7535.90	1.9805e-09
34	606.30	4.3394e-10	74	8042.70	1.9164e-09
35	647.20	6.9412e-10	75	8563.00	2.6711e-09
36	688.90	3.8728e-10	76	9165.10	2.2083e-09
37	731.80	6.5521e-10	77	9750.60	2.8832e-09
38	774.60	2.4288e-10	78	10210.00	3.8164e-09
39	833.60	5.5078e-10	79	11123.00	4.8872e-09
40	878.80	2.4876e-10	80	11844.00	6.0993e-09

Table 10.3.4.2.1 MFR ExLo Bench Noise Plot (220 pF || 10 M )

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	3.8826e-11	41	940.50	4.0367e-15
2	25.80	1.0598e-11	42	1003.70	1.8801e-15
3	28.60	9.5246e-12	43	1068.60	8.5983e-15
4	31.90	1.5304e-11	44	1152.20	5.0360e-15
5	35.80	1.7657e-11	45	1221.20	4.6635e-15
6	40.90	4.4648e-12	46	1310.10	7.9548e-15
7	46.00	4.9808e-12	47	1383.40	5.0760e-15
8	52.30	1.7952e-11	48	1478.10	4.1985e-15
9	59.90	9.6492e-11	49	1581.90	3.5152e-13
10	69.00	1.9065e-12	50	1716.80	1.8381e-14
11	79.50	2.4007e-13	51	1830.10	8.4549e-15
12	91.80	3.6885e-13	52	1944.20	1.0964e-13
13	106.70	3.4145e-13	53	2128.30	2.5231e-14
14	123.90	4.9362e-13	54	2314.60	2.7978e-14
15	144.40	2.7084e-13	55	2361.40	5.5457e-15
16	168.50	6.6306e-13	56	2526.60	1.3224e-14
17	200.10	6.1263e-14	57	2693.30	5.4647e-15
18	222.60	2.5308e-14	58	2861.70	1.7627e-14
19	233.90	2.4801e-14	59	3056.20	1.1679e-14
20	245.40	1.9852e-14	60	3253.00	6.2201e-15
21	268.40	2.1159e-14	61	3477.10	4.8378e-15
22	280.00	2.5866e-14	62	3704.10	4.5950e-15
23	303.40	5.1135e-14	63	4037.30	8.8737e-15
24	315.20	1.3298e-14	64	4324.20	2.9541e-14
25	339.00	5.3696e-14	65	4696.30	5.2517e-14
26	363.10	1.4792e-14	66	4858.10	7.0365e-14
27	387.40	1.7545e-14	67	5131.10	1.4193e-14
28	412.00	1.2339e-14	68	5464.20	5.7480e-15
29	437.00	1.7521e-14	69	5803.50	1.7403e-14
30	462.20	1.0763e-14	70	6207.30	4.9639e-15
31	500.50	1.5479e-14	71	6620.10	5.3756e-15
32	526.50	4.5320e-15	72	7072.50	7.3359e-15
33	566.00	1.3545e-14	73	7535.90	3.9658e-15
34	606.30	1.8104e-14	74	8042.70	4.1861e-15
35	647.20	3.5986e-15	75	8563.00	4.8568e-15
36	688.90	1.1516e-14	76	9165.10	5.0310e-15
37	731.80	7.1553e-15	77	9750.60	4.6990e-15
38	774.60	6.7307e-15	78	10210.00	7.5990e-15
39	833.60	8.1921e-15	79	11123.00	7.0746e-15
40	878.80	4.1560e-15	80	11844.00	4.5642e-15

Table 10.3.4.2.2 MFR In-Flight ExLo Noise Plot (220pf)

Channel	Frequency

(Hz)	V2/Hz	Channel	Frequency

(Hz)	V2/Hz
1	23.40	1.2353e-11	41	940.50	8.2379e-15
2	25.80	9.2171e-12	42	1003.70	7.5204e-15
3	28.60	4.3857e-12	43	1068.60	8.5983e-15
4	31.90	4.4753e-12	44	1152.20	6.3738e-15
5	35.80	4.8878e-12	45	1221.20	2.7507e-14
6	40.90	1.8450e-12	46	1310.10	3.8980e-15
7	46.00	1.3824e-12	47	1383.40	3.8858e-15
8	52.30	2.8241e-12	48	1478.10	2.1423e-15
9	59.90	1.0326e-12	49	1581.90	3.2676e-13
10	69.00	5.8028e-13	50	1716.80	1.1118e-14
11	79.50	4.7054e-13	51	1830.10	1.1510e-14
12	91.80	4.9113e-13	52	1944.20	2.4736e-14
13	106.70	2.4447e-13	53	2128.30	1.9642e-14
14	123.90	1.2341e-13	54	2314.60	1.4802e-14
15	144.40	1.5236e-13	55	2361.40	7.7457e-15
16	168.50	2.9466e-13	56	2526.60	6.2499e-15
17	200.10	4.7442e-14	57	2693.30	2.6021e-14
18	222.60	1.7574e-14	58	2861.70	8.6379e-15
19	233.90	1.5003e-14	59	3056.20	1.3186e-14
20	245.40	7.3837e-14	60	3253.00	1.5596e-14
21	268.40	2.4289e-14	61	3477.10	3.9982e-15
22	280.00	2.8998e-14	62	3704.10	7.4435e-15
23	303.40	1.0742e-14	63	4037.30	6.6655e-15
24	315.20	2.0780e-14	64	4324.20	1.5312e-14
25	339.00	2.4962e-14	65	4696.30	3.3612e-14
26	363.10	2.3113e-14	66	4858.10	3.6703e-14
27	387.40	2.6575e-14	67	5131.10	1.1362e-14
28	412.00	1.2339e-14	68	5464.20	4.8976e-15
29	437.00	3.1150e-14	69	5803.50	1.2575e-14
30	462.20	8.7180e-15	70	6207.30	4.1712e-15
31	500.50	1.0002e-13	71	6620.10	3.7333e-15
32	526.50	1.1191e-14	72	7072.50	3.5160e-15
33	566.00	9.4059e-15	73	7535.90	9.4714e-15
34	606.30	7.4816e-15	74	8042.70	3.4601e-15
35	647.20	8.0974e-15	75	8563.00	5.7002e-15
36	688.90	6.0920e-15	76	9165.10	5.0310e-15
37	731.80	5.6536e-15	77	9750.60	3.9485e-15
38	774.60	8.3094e-15	78	10210.00	1.0118e-14
39	833.60	6.4728e-15	79	11123.00	5.1976e-15
40	878.80	5.4283e-15	80	11844.00	5.4316e-15

Table 10.3.4.2.3 MFR Bx Bench Noise Plot

Channel	Frequency

(Hz)	nT2/Hz	Channel	Frequency

(Hz)	nT2/Hz
1	23.40	8.7224e-07	41	940.50	4.9002e-10
2	25.80	3.0116e-07	42	1003.70	7.1969e-10
3	28.60	1.3429e-07	43	1068.60	3.8582e-10
4	31.90	1.0627e-07	44	1152.20	6.0502e-10
5	35.80	8.3312e-08	45	1221.20	5.7067e-10
6	40.90	1.9907e-07	46	1310.10	6.1370e-10
7	46.00	8.4046e-07	47	1383.40	6.1284e-10
8	52.30	4.0902e-06	48	1478.10	3.8782e-10
9	59.90	3.0581e-05	49	1581.90	3.0074e-09
10	69.00	1.3217e-06	50	1716.80	9.5305e-10
11	79.50	5.1971e-08	51	1830.10	1.2400e-09
12	91.80	1.4943e-08	52	1944.20	1.3470e-09
13	106.70	2.3355e-07	53	2128.30	1.4771e-09
14	123.90	5.3205e-07	54	2314.60	1.5098e-09
15	144.40	1.7509e-08	55	2361.40	1.1225e-09
16	168.50	4.3995e-07	56	2526.60	1.2696e-09
17	200.10	3.1684e-06	57	2693.30	9.0248e-10
18	222.60	2.3264e-08	58	2861.70	1.0188e-09
19	233.90	4.1438e-09	59	3056.20	1.1329e-09
20	245.40	7.7991e-09	60	3253.00	1.3824e-09
21	268.40	9.9422e-10	61	3477.10	1.2838e-09
22	280.00	7.9735e-09	62	3704.10	1.2967e-09
23	303.40	9.1908e-08	63	4037.30	1.2768e-09
24	315.20	1.5470e-07	64	4324.20	1.7217e-09
25	339.00	2.2296e-09	65	4696.30	2.0345e-09
26	363.10	2.0669e-09	66	4858.10	2.9729e-09
27	387.40	7.7112e-10	67	5131.10	1.2157e-09
28	412.00	1.1662e-08	68	5464.20	1.2602e-09
29	437.00	6.5289e-08	69	5803.50	1.7143e-09
30	462.20	1.3440e-09	70	6207.30	1.4432e-09
31	500.50	1.5999e-09	71	6620.10	1.2603e-09
32	526.50	7.7544e-10	72	7072.50	2.0443e-09
33	566.00	2.1965e-09	73	7535.90	1.4152e-09
34	606.30	6.9421e-10	74	8042.70	1.5176e-09
35	647.20	4.8049e-09	75	8563.00	1.8376e-09
36	688.90	8.0556e-10	76	9165.10	2.5294e-09
37	731.80	6.6836e-10	77	9750.60	1.7510e-09
38	774.60	2.0952e-09	78	10210.00	2.4805e-09
39	833.60	8.6228e-10	79	11123.00	6.4390e-09
40	878.80	3.7801e-10	80	11844.00	4.6106e-09