Previous topic | Next topic 
| Parent topic 
This table contains the following sections:
- A complete task specification file outline with all possible statements and blocks, including:
- File specifications
- Pre-FFT process parameters
- Post-FFT process parameters
- The CompositeFilter Begin - End block
- Compound derivative filters
- The possible filter description blocks for the CompositeFilter Begin - End block
| Statement | Description | Unit | Default | ||
|---|---|---|---|---|---|
| GridFFT task specification (.job) file | |||||
| Process Begin | Task definition | ||||
| Name = gfilt | Specifies GridFFT as the application for this task. | ||||
| Parameters Begin | Start of parameters block | ||||
| File specifications | |||||
| InputGridName = <path> | The input grid, with relative or absolute path if necessary. Can be a spatial or an FFT grid. | oblig | |||
| Band = <ord> | Band of grid to be filtered | 1 | |||
| FilteredGridName = <path> | The filtered output grid, with relative or absolute path if necessary. | calc | |||
| OutputPrecision = <datatype> | Precision of data in filtered output grid. | IEEE4byteReal | |||
| FftGridName = <path> | FFT of the input grid for use in future tasks. | not saved | |||
| ExpandedGridName = <path> | Expanded and filled intermediate grid. INTREPID normally deletes it. Save it if required for debug check. | not saved | |||
| WindowedGridName = <path> | Expanded grid with rolloff applied to edges. INTREPID normally deletes it. Save it if required for debug check. | not saved | |||
| Pre-FFT process | |||||
| DetrendDegree = <0|1|2> | De-trend the spatial grid using a polynomial of degree n (0 is a constant, 1 is a slope, 2 is curved). | 1 | |||
| FillType = <NONE|ARTHUR|MEM|SOURCE_GRID> | Fill type for dummy data in new cells of expanded grid, Arthur is a "plug" fill at various frequencies, Source_Grid uses a larger initial real dataset to sample from, in the immediate area of interest. |
ARTHUR | |||
| RolloffType = <COSINE| LINEAR| NONE> | Roll-off type for the edge of the expanded grid. Use RolloffType OR WindowType, not both. Set RolloffType to NONE if you use WindowType | COSINE | |||
| WindowType = <COSINE_BELL| HANNING|HAMMING| BLACKMAN|TRIANGLE|NONE> | Roll-off method applied across the whole of the grid. Use RolloffType OR WindowType, not both. Set WindowType to NONE if you use RolloffType | NONE | |||
| Post-FFT process | |||||
| ReApplyTrendAfterReverseFft = <YES|NO> | Restore the trend that was removed in pre-FFT grid conditioning . | NO | |||
| ApplyMaskAfterReverseFft = <YES|NO>}} | Use the input grid to restore all nulls in the filtered output grid. | NO | |||
| PowerSpectrumGridName = psgn.ers |
Save off an image of the 2D power spectrum coefficients scaled using a log function |
NONE |
|||
| InputRadialPowerSpectrumReport = magfin_power.rpt | Save an ascii column report of the input grids radially averaged power coefficients, suitable for use in EXCEL |
NONE |
|||
| OutputRadialPowerSpectrumReport = magfin_power.rpt | Save the post-filtered radially averaged power spectrum in an ascii file, comma separated |
NONE |
|||
| Special Filter Operations |
|||||
| InputGridCoordSysType = <ENU|NED|END> |
Field measurement coordinate system,eg EastNorthUp nb "END" must be quoted, as it is already a restricted keyword |
||||
| CalculateTensorIntegration = Yes | The filter operation required is the special operation of tensor integration, requires you start with a tensor grid |
NO |
|||
| ScaleTensorIntegration = Yes | Change the units from Eotvos to mGals | NO |
|||
| InputTensorComponents = <TezTnzTzz_to_Tz|TezTnz_to_Tz|Tzz_to_Tz> | Specification of input channels to produce the one output. Can be up to 3 inputs |
TezTnzTzz_to_Tz | |||
| CalculateAnalyticSignal = 1 |
Calculate an analytical signal grid, ie SQRT(X*X+Y*Y+Z*Z) of the 3 spatial derivatives |
NO |
|||
| CalculateTiltAngle = 1 | Calculate a tilt signal grid, ie atan(SQRT(X*X+Y*Y),Z) of the 3 spatial derivatives | NO |
|||
| ImagePresentation Begin ... ImagePresentation End | GridFFT uses these statements in ArcView, but ignores them here. | ||||
| Subset Begin |
Subset a large grid |
||||
| XLower = 720000 | world coordiantes for clipping left | ||||
| XUpper = 750000 | world coordiantes for clipping right | ||||
| YLower = 8530000 | world coordiantes for clipping bottom | ||||
| YUpper = 8550000 | world coordiantes for clipping top |
||||
| FFTborder = 5000 | extra distance in meters required for the fill boundary on the exterior |
||||
| SubsetGridName = anal_subset | keep a copy of the subsettted grid |
||||
| Subset End | |||||
| Filter definitions | |||||
| CompositeFilter Begin | Composite filter definition Do not use with: CalculateHorizonatlDerivative or CalculateAnalyticSignal | ||||
| ... Begin ... ... End | Filter definition within composite filter (see 'Filter definitions' below) | ||||
| ... | More filter definitions if required | ||||
| CompositeFilter End | |||||
| CalculateHorizontalDerivative = <YES|NO> | Total horizontal derivative Do not use with CompositeFilter or CalculateAnalyticSignal | NO | |||
| CalculateAnalyticSignal = <YES|NO> | Analytic signal Do not use with: CompositeFilter CalculateHorizonatlDerivative | NO | |||
| DiskUsageRule=<AUTO|FORCE_MEMORY|FORCE_DISK> | Override the internal logic if possible, to favour disk based, memory based data buffering |
AUTO |
|||
| UseSymmetry=YES |
exploit any symmetry in the FFT grid space to save memory and disk space, nb some filters cannot make use of this, as they are inherently asymmetric |
YES |
|||
| Parameters End | |||||
| Process End | |||||
| Filter definitions within CompositeFilter block | |||||
| HorizontalDerivative2D Begin | Generalised horizontal derivative definition | ||||
| Azimuth = <number> | Direction for horizontal derivative. 0 = grid Y 90 = grid X | ° | 0 | ||
| Degree = <number> | The degree of the derivative. (1 = first derivative) | 1 | |||
| HorizontalDerivative2D End | |||||
| VerticalDerivative2D Begin | Vertical derivative definition | ||||
| Degree = 1 | The degree of the derivative. (1 = first derivative) | 1 | |||
| VerticalDerivative2D End | |||||
| Continuation2D Begin | Continuation filter definition | ||||
| Distance = <number> | Continuation distance | m or ° | oblig | ||
| UseDamping = <YES|NO> | Apply roll-off to higher frequencies? (downward continuation only) | NO | |||
| DampingDegree = <0..15> | Degree of damping roll-off | 10 | |||
| DampingFrequency = <number> | Median frequency for damping rolloff | cyc/m or cyc/° | calc | ||
| Continuation2D End | |||||
| LowPass2D Begin | Low pass filter definition | ||||
| Cutoff = <number> | Cutoff frequency for low pass filter | cyc/m or cyc/° | oblig | ||
| Rolloff = <number> | Frequency for start of rolloff. If this statement is present, it sets AutoRolloff = NO | cyc/m or cyc/° | oblig* | ||
| AutoRolloff = <YES|NO> | NO Rolloff = statement is required YES Automatic rolloff at 0.5 x Cutoff value | YES | |||
| LowPass2D End | |||||
| HighPass2D Begin | High pass filter definition | ||||
| Cutoff = 0.001 | Cutoff frequency for high pass filter | cyc/m or cyc/° | oblig | ||
| Rolloff = <number> | Frequency for start of rolloff. If this statement is present, it sets AutoRolloff = NO | cyc/m or cyc/° | oblig 1 | ||
| AutoRolloff = <YES|NO> | NO Rolloff = statement is required YES Automatic rolloff at 0.5 x Cutoff value | YES | |||
| HighPass2D End | |||||
| BandPass2D Begin | Band pass filter definition | ||||
| Low = <number> | Cutoff frequency for low pass filter | cyc/m or cyc/° | oblig | ||
| High = <number> | Cutoff frequency for high pass filter | cyc/m or cyc/° | oblig | ||
| LowRolloff = <number> | Frequency for start of low end rolloff. If this statement is present, it sets AutoRolloff = NO | cyc/m or cyc/° | oblig* | ||
| HighRolloff = <number> | Frequency for start of high end rolloff. If this statement is present, it sets AutoRolloff = NO | cyc/m or cyc/° | oblig* | ||
| AutoRolloff = <YES|NO> | NO LowRolloff = and HighRolloff = statements are required YES Automatic rolloff at 0.5 x Low and 0.5 x High values respectively | YES | |||
| BandPass2D End | |||||
| Reduction2D Begin | Reduction filter definition | ||||
| FromInclination = <number> | Inclination of source data. INTREPID calcluates default from middling latitude and longitude, using IGRF model | ° | calc | ||
| FromDeclination = <number> | Declination of source data. INTREPID calcluates default from middling latitude and longitude, using IGRF model | ° | calc | ||
| Date | Date of source data in format DD/MM/YYYY | Epoch 2000 | |||
| Elevation | Elevation of source data | m | 0 | ||
| ToInclination = <number> | Inclination of output data | ° | 90 (pole) | ||
| ToDeclination= 0 | Declination of output data | ° | 0 | ||
| AmplitudeLimit= 20.0 | Latitude for amplitude limiting | ° | 20 | ||
| LowLatitude = <YES|NO> | Turn on/off directional cosine filter | ||||
| Reduction2D End |
1 If Auto Rolloff = NO, then this statement is required and you must assign a value.
| Version | Date | Comment |
|---|---|---|
| Current Version (v. 12) | Feb 10, 2012 10:50 | Laurie (loz) |
| v. 11 | Jun 10, 2010 14:04 | David Stephensen |
| v. 10 | Apr 07, 2010 15:20 |
David Stephensen:
This is a comment describing a change that I made, just like in CVS. I fixed an intermediate header row |
| v. 9 | Apr 07, 2010 15:02 | David Stephensen |
| v. 8 | Apr 07, 2010 15:00 | David Stephensen |
| v. 7 | Apr 07, 2010 14:44 | David Stephensen |
| v. 6 | Apr 07, 2010 14:42 | David Stephensen |
| v. 5 | Apr 07, 2010 14:38 | David Stephensen |
| v. 4 | Apr 05, 2010 02:51 | Des |
| v. 3 | Apr 05, 2010 02:37 | Des |
| v. 2 | Apr 05, 2010 02:18 | Des |
| v. 1 | Apr 01, 2010 16:52 | David Stephensen |
Labels:
None
1 Comment
comments.show.hide-
-
Permalink
Add CommentApr 02, 2010
Des
the option to also allow subsetting and filling from real data does not appear in the documentation
arthur/mem/subset
for this you also need to keep track of the original larger dataset grid