Venkatesh,
The OM 1d_fft tools menu can be used to do a power spectrum on a single line of
data the menu paths when the tools menu is loaded is FFT1D -> and a channel of
input and output are specified as seen below-
--------------------------------------------------------------------------------------------------------------------------
Power Spectrum
Use the Power Spectrum menu option (FFTPSPEC GX) to calculate the log power
spectrum of a channel.
Log Power Spectrum dialog options
| Channel | Name of the Input Channel.Script Parameter: FFTPSPEC.IN |
| Power spectrum output channel | Name of Power Spectrum output channel.Script
Parameter: FFTPSPEC.OUT |
Application Notes
The power spectrum will be a natural log of the power.The fiducial increment
will be cycles per original fiducial. The profile is extended to a power of 2
times the length and the wavenumber increment will be 1/(length *
fid_increment).----------------------------------------------------------------------------------------------------------------------------
If just one line is desired, switch off all other lines and run the routine on
the one selected line.
Geosoft's Magmap will do gridded data power spectra it's believed but I don't
have this menu activated at present on my OM copy. That may be another tool to
look at.
An alternative grid power spectra utility is the Grid Matched Filtering Power
Spectra routine in the USGS GX's for Geosoft OM where the power spectra of the
grid is presented as a curve and the user can then fit the power spectra
graphically on-screen using a sequence of linear segments. This matched
filtering tool is very handy for producing frequency/wavelength based grids
from various inferred depths and the highest frequency/shortest wavelength grid
is often useful for flight line noise removal from TMI and gravity gradiometer
datasets. Jeff Phillips at the USGS is the author of these routines.
Regards,
Ed
Red Rocks Geophysical ConsultingLakewood, Colorado80228 USAmobile voice/text
720-300-3641
On Wednesday, August 10, 2016 7:39 AM, "solomonjanjaro
<[email protected]>" <[email protected]> wrote:
Venkatesh
If i understand what you mean... You need to window smaller blocks of your grid
so that you can calculate their power spectrum one by one
Solomon Nehemiah Yusuf.
UnimaidOn 10 Aug 2016 5:50 am, "venkatesh <[email protected]>"
<[email protected]> wrote:
Hi,
i need help on to how to calculate power spectrum for different profiles for
same grid .because i know for grid to power spectrum calculation. can any body
help on this topic
VenkateshGeophy
--
With Warm Regards.S.Venkateswar Rao------------------------------
-----S.Venkateswara RaoSr.Geophysicist,Gravity & Magnetic LabInstitute of
Seismological Research(ISR),Next to PDPU,
Raisan,Gandhinagar,Gujarat-382009,INDIA.Phone 079-66739011(O), Mobile:
+91-9824496343e mail: [email protected] & [email protected] --- Forum
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