Applied Geophysics : Seismics

Seismometer-Galvanometer Coupling

Applet ( in separate window, approx. 320 x 460 Pixel )

The applet shows in separate windows
  a schematic diagram of the coupling network, and
  an interactive graphic display of normalized coupling parameters,
and allows
  to set relevant seismometer and galvanometer parameters in a dialogue area
  and
  to adjust the coupling network in the graphic display.

( Background : see Seismometer-Galvanometer Documentaion, in separate window )

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Applet Dialogue :
( Screenshot )

COUPLING DIAGRAM SHOW
  shows / hides a schematic diagram of the coupling network.

ADJUST RESISTANCE - T SHOW
  shows / hides a graphic display of normalized coupling parameters.

NO INSTR / USER PAR / KIRNOS
  controls the parameter dialogue and
  the parameter adjustment in the graphic display window.

  NO INSTR disables the parameter dialogue and allows the adjustment of all normalized parameters in the graphic display.

  USER PAR and KIRNOS enable the parameter dialogue and inhibit the adjustment of the normalized parameters in the graphic display ( q_σ only is adjustable ).

INF and HLP display
  informations to the actual cursor position ( INF )
and / or
  hints to actually possible mouse actions ( HLP )
in the graphic display window.

Parameter Dialogue :
( Screenshots )

Example USER PAR

The screeshot shows the min. set of parameters, i.e.
  coil and damping resistances of both instruments, Rc_s / g and Rd_s / g,
  while the instrument parameters CDR, α0 and α are unused.

If CDR, α0 and α are set to compatible values,
  α_max ( max. possible damping ) and Rd ( damping resistance ) are calculated and displayed.
  ( Incompatible prameter values result in error messages in the field ERR: )

If the parameters of both instruments ( seismometer and galvanometer ) are set
  σ_max ( max. possible coupling coefficient ) is calculated and displayed ( σ_m, > 0, < 1 ).

Example KIRNOS

The instrument parameters are preset with
  values of a Kirnos seismograph system,
leading to
  values α_max and Rd for both instruments and the value σ_max.

The values Re_s, Re_g, Re_0 and σ^2
  depend on q_σ ( adjustable in the graphic parameter display, see below ).

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- Screenshots -

Circuit Diagram
( see Seismometer-Galvanometer Documentation, in seperate window. )

Graphical Display
( Parameter values see dialogue examples above )

Color code :
red = seismometer, blue = galvanometer, magenta = Rd_g/Rd_s or Rd_s/Rd_g, cyan = q_&sigma

For given normalized parameters Rd_g/Rd_s, Rc_s/Rds and Rc_g/Rd_g the quotients
  R_s / Rd_s = (Rc_s+Re_s) / Rd_s and R_g / Rd_g = (Rc_g+Re_g) / Rd_g
are displayed as functions of
  q_σ = σ / σ_max
in the range 0 ... 1 for q_σ and both functions.

Values of q_σ and of both functions outside this range are meaningless for the coupling problem.
( Details see Seismometer-Galvanometer Documentation )

The normalized coil resistances Rc_s/Rd_s and Rc_g/Rd_g
  are displayed as horizontal lines :
red / blue, where the distance to the resp. functions,
i.e. the normalized external resistances
  Re_s/Rd_s resp. Re_g/Rd_g, are ≥ 0.

The range of q_σ, where both resistances
  Re_s and Re_g are ≥ 0
is marked green,
  denoting the range of q_σ, compatible with the given dampings, i.e. damping resistances.

In mode NO INSTR the normalized parameters can be adjusted at scales :
  Rd_g/Rd_s or Rd_s/Rd_g below ( magenta, 0.01 ... 1 ),
  Rc_s/Rd_s left ( red, 0.01 ... 0.95 ) und
  Rc_g/Rd_g right to the display ( blue, 0.01 ... 0.95 ).
For USER PAR and KIRNOS these paramters
  are set in the parameter dialogue of the applet.

The value of q_σ can be adjusted in all three modes at the scale above the display.

Parameter scales :
  left mouse button -> drag,
  right button -> set value,
lower left edge :
  left mouse button -> scale = Rd_g/Rd_s,
  right button -> scale = Rd_s/Rd_g.

In a text area at the upper edge of the display window
  the first line lists the values of the normalized parameters,
and below
  the actual value of q_σ and the resulting normalized coupling resistances are displayed.

Example NO INSTR
( Parameter values : preset at start of the applet )

Example USER PAR
( Parameter values : preset at start of the applet )

Example KIRNOS
( Parameter values : preset selecting KIRNOS )

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Class and html files for a local installation of the applet are available as a zip file and as a tar.gz file.

More applets at : Geophysics Department TU Clausthal

Rev. 12-nov-2012

Comments to Fritz Keller
( ned gschempfd isch globd gnueg )

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