TF Values not in agreement between SPUD and Aurora

[kkappler]

For CAS04 we get good agreement, e.g.

But for ORF08 we do not, it looks like this:

Need to know more about the systems, but the calibration functions appear different; Consider: ORF08 Ex has a Total response amplitude on the order of 1e10: But CAS04 Ex has as response around 1e5:

ORF Hx around 1e11 But CAS04 Hx has as response around 1e2:

So we have a nominal E/H at ORF08 around 0.1, but at CAS04 around 1e3, 4 orders of magnitude difference in ratio, which FWIW is not easily explained by mV/km to V/m

[kkappler]

Issues include:

• [x] Calibration data are inconsistent
• [x] Aurora seems to be treating the data at incorrect sample rate (data should be 8Hz)

[kkappler]

The ex filters for ORF08, pasted below, use a single stage to convert from counts to volts, and then a second stage to convert to V/m. The hx filter is a single stage going from counts to Tesla.

ORF08 Electric Filters Example:

Filters Included:

pole_zero_filter: calibration_date = 1980-01-01 gain = 99.9996 name = zpk_01 normalization_factor = 1.0 poles = [-0.00016667+0.j] type = zpk units_in = V/m units_out = V zeros = [0.+0.j]

pole_zero_filter: calibration_date = 1980-01-01 gain = 409600000.0 name = zpk_02 normalization_factor = 313384.0 poles = [ -3.88301+11.9519j -3.88301-11.9519j -10.1662 +7.38651j -10.1662 -7.38651j -12.5664 +0.j ] type = zpk units_in = V units_out = count zeros = []

ORF08 Magnetic Filter Example:

Filters Included:

pole_zero_filter: calibration_date = 1980-01-01 gain = 100000000000.0 name = zpk_00 normalization_factor = 1984.31 poles = [ -6.28319+10.8825j -6.28319-10.8825j -12.5664 +0.j ] type = zpk units_in = T units_out = count zeros = []

[kkappler]

The ex filters for CAS04, pasted below, use a six stages, but most importantly have a 1e6 gain stage to go to mV/km from V/m. The magnetic has three stages, and outputs to nT.

CAS04 Electric Filters Example

Filters Included:
=========================
coefficient_filter:
    calibration_date = 1980-01-01
    comments = practical to SI unit conversion
    gain = 1e-06
    name = electric_si_units
    type = coefficient
    units_in = mV/km
    units_out = V/m
--------------------
coefficient_filter:
    calibration_date = 1980-01-01
    comments = electric dipole for electric field
    gain = 92.0
    name = electric_dipole_92.000
    type = coefficient
    units_in = V/m
    units_out = V
--------------------
pole_zero_filter:
    calibration_date = 1980-01-01
    comments = NIMS electric field 5 pole Butterworth 0.5 low pass (analog)
    gain = 1.0
    name = electric_butterworth_low_pass
    normalization_factor = 313383.493219835
    poles = [ -3.883009+11.951875j  -3.883009-11.951875j -10.166194 +7.386513j
 -10.166194 -7.386513j -12.566371 +0.j      ]
    type = zpk
    units_in = V
    units_out = V
    zeros = []
--------------------
pole_zero_filter:
    calibration_date = 1980-01-01
    comments = NIMS electric field 1 pole Butterworth high pass (analog)
    gain = 1.0
    name = electric_butterworth_high_pass
    normalization_factor = 1.00000000378188
    poles = [-0.000167+0.j]
    type = zpk
    units_in = V
    units_out = V
    zeros = [0.+0.j]
--------------------
coefficient_filter:
    calibration_date = 1980-01-01
    comments = analog to digital conversion (electric)
    gain = 409600000.0
    name = electric_analog_to_digital
    type = coefficient
    units_in = V
    units_out = count
--------------------
time_delay_filter:
    calibration_date = 1980-01-01
    comments = time offset in seconds (digital)
    delay = -0.285
    gain = 1.0
    name = electric_time_offset
    type = time delay
    units_in = count
    units_out = count
--------------------

CAS04 Magnetic Filters Example

Filters Included:
=========================
pole_zero_filter:
    calibration_date = 1980-01-01
    comments = NIMS magnetic field 3 pole Butterworth 0.5 low pass (analog)
    gain = 1.0
    name = magnetic_butterworth_low_pass
    normalization_factor = 2002.26936395594
    poles = [ -6.283185+10.882477j  -6.283185-10.882477j -12.566371 +0.j      ]
    type = zpk
    units_in = nT
    units_out = V
    zeros = []
--------------------
coefficient_filter:
    calibration_date = 1980-01-01
    comments = analog to digital conversion (magnetic)
    gain = 100.0
    name = magnetic_analog_to_digital
    type = coefficient
    units_in = V
    units_out = count
--------------------
time_delay_filter:
    calibration_date = 1980-01-01
    comments = time offset in seconds (digital)
    delay = -0.192
    gain = 1.0
    name = hx_time_offset
    type = time delay
    units_in = count
    units_out = count
--------------------

[kkappler]

After "cheating" si unit conversion filters into ORF08 and ORG08(the RR) we get:

Which has no ryx.

I had to replicate not only the filters, but the entire channel metadata (but then overwrite with the correct time period). Then I get:

[kkappler]

Results are now in good agreement where processing bands overlap.