ArchaeoSignal | Archaeological Magnetometry Processing

＋Your magnetic survey will appear hereLoad survey files or open the demonstration dataset

Load one or more survey filesX · Y · nT

Tile controls

Select a tile on the canvas or in the list

Display & paletteselected tile

Tile display range, nT

Palette Invert paletteThe range changes only the selected tile view; magnetic values remain unchanged.

Manual processingComplete standard toolset for the selected tile

changes apply immediately

Select a tileUndo is always available

Processed range—2nd–98th percentile, nT

σ—standard deviation

Acquisition line correctionscorrect paired sensors and forward/reverse traverse timing before resampling

Paired sensor / traverse correctionThis acts on imported acquisition lines before crop and resampling—not on output pixels. An unavailable direction has no stable repeated line coordinates in the file.

Destaggerforward / reverse traverse lag

Shift direction

Lines / traverseShift, cells

Aligns repeated anomaly edges between alternating traverses. It does not change magnetic amplitudes.

Survey extent & resamplingset the exact active bounds and create the output raster lattice

Tile cropfull imported extent

X min

X max

Y min

Y max

Width, m

Height, m

Crop rule

Creates a new raster lattice on the cropped coordinates: −0.25…40.25 becomes nodes spanning exactly 0…40 m. Processing, outlines, snapping, the unified survey and exports all use this recalculated grid.

Orientation & placementrotate or position the cropped tile without changing source coordinates

Shift X, m

Shift Y, m

Rotation, °

Quick rotate

Keyboard nudge, m

Snap tolerance, m

Tile opacity 100%

You can still drag the tile directly on the map. Rotation and shifts are reversible with Undo.

Level & line noiseremove offsets, spikes and axis-aligned acquisition stripes

Zero-level correction

Robust line leveling

Despike threshold, MAD

Local despike replaces only isolated unsupported cells. Connected positive or negative anomalies are preserved. Set 0 to switch it off; 5 MAD is conservative.

Directional destriping — advancedonly for oblique acquisition stripes that row/column leveling cannot follow

Line angle, °

Strength

This raster-based filter is deliberately conservative: weak detections are rejected and automatic strength is 0.4. Set strength to 0 to switch it off; verify long linear anomalies before using a stronger value.

Spatial filtersoptional; use after geometry and line corrections

Low-pass radius, cells

High-pass radius, cells

Fractional radii are supported. Low-pass smooths fine noise; high-pass subtracts a broad local background. Using both produces a band-pass result. A value of 0 keeps that filter off.

Amplitude calibrationapply a linear gain and constant field offset

Gain ×

Offset, nT

Output = processed field × gain + offset. Arrow steps are 0.01× and 0.1 nT; Shift is 10× coarser and Alt 10× finer. AI values are rounded here only for display.

Recommended order: paired sensor correction → destagger → crop and resample → orientation → local despike → zero level → line leveling → optional directional destriping → optional spatial filters → gain and offset. Gridding and small-gap interpolation remain automatic.

Survey frame & export

Survey frame & griddefines the exact PNG map area

PNG map layoutIncludes a structured survey metadata block below the map.

Map details

Site / object nameSurvey area / sectorSurvey year or dateAuthors

Enter a site or object name to include it in the exported map title. Enter a year (for example 2026) or a full date (2026-08-26).

Professional survey metadata

Survey methodInstrument / modelSensor configurationOrganisation / projectTraverse spacing, mSample spacing, mCoordinate reference / EPSGFigure / map IDNorth referenceProcessing summary

Only choose a north reference when the map's upward Y direction is known. These fields are stored in the project; the full block is printed by the professional layout.

Custom survey frame

X min, m

Y min, m

Width, m

Height, m

X and Y may be negative. Type any value and press Enter or leave the field. Arrow keys use the shown parameter step; Shift makes it 10× larger and Alt 10× finer.

Show survey grid

Cell width, m

Cell height, m

Snap cropped tile edges to tiles, frame and gridDragging now locks to exact grid coordinates, not fractional fitted-frame edges. Use Align all tiles once to remove existing residuals such as 80.125 m; Fit frame then rounds the map boundary to the same lattice.

Data export scopeData export format

The scope selector applies to data export; PNG always uses the visible survey and optional survey frame. GeoTIFF stores Float32 nT values, NoData, pixel size, origin and the chosen EPSG code. GRD and ASC remain available for Surfer and GIS workflows.