Closing Angle · Least Squares Traverse Adjustment by Shields Precision

1Upload field data
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The raw file from your data collector. Carlson / SurvCE: export the job’s .raw (or .rw5). Trimble Access: export JobXML (.jxl). Every angle, distance, HI and rod height is read from it; nothing is changed in your file.

Drop a .raw, .rw5 or .jxl file here
or click to choose · Carlson / SurvCE and Trimble JobXML today, Sokkia next

Add GPS / control points (optional) · .csv or .txt, comma delimited. Use this to balance an open traverse to GPS.

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A point file of GPS shots taken on some of your traverse points (point, northing, easting, elevation, description). The GPS points can have their own numbers; put the traverse point in the description, like “GPS ON TRAV 7”, and the tool will match them. You confirm every match in step 2.

Column order

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How the columns in your GPS file are arranged. PNEZD = Point, Northing, Easting, Elevation, Description (the most common). PENZD swaps northing and easting.

2Control
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Control is what ties the traverse to the ground: points with known coordinates. A traverse on its own has the right shape but could sit anywhere and point any direction, so it has to be held to something. More in the guide.

Fit to GPS (trust the traverse) Balance to GPS (trust the GPS) Hold a point and direction

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Fit to GPS: trust the traverse, use GPS only to place and turn it. Pick this when the traverse is tight and the GPS is so-so (trees, buildings).

Balance to GPS: every GPS point pulls the traverse toward it. Pick this only when the GPS is good.

Hold a point and direction: ignore the GPS file and hold the given coordinates from your data collector.

Check which traverse point each GPS point sits on. Suggestions come from the descriptions and distances; change any that are wrong, or pick "not used". Give a weak GPS shot a bigger ± if you know it was poor.

GPS point	Description	Sits on	± ft	Why

Using typical RTK accuracy (±0.03 ft horizontal, ±0.05 ft vertical). Change it under advanced settings.

Default GPS accuracy ± ft: horizontal vertical Typical RTK in the open: 0.03 / 0.05. Used to weight GPS when balancing and to flag points that are off.

Pick the point to hold and a second point that sets the direction (bearing). Every other point with given coordinates is used as a check.

Held point

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This point keeps its given coordinates exactly. Everything else is computed from it. Usually the point you started on.

Direction to

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The bearing from the held point to this point is held, which sets the rotation of the whole traverse. Usually your first backsight. Its coordinates are not held unless you tick the box below, so its distance becomes a check.

Also hold at its given coordinates (fixes distance/scale too, not just direction)

3How it was measured
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Tells the adjustment how good your measurements should be, so it can spread errors fairly and spot shots that are worse than the instrument should allow.

Instrument

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The angle accuracy printed on your total station (1″, 2″, 5″…). If the file includes it, “From data collector” is picked for you. Too tight a setting makes good work look bad; too loose hides mistakes.

Prisms in this file
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A prism constant is a small distance correction (often −30 mm or 0 mm) for where the light reflects inside the prism. A wrong one makes every distance to that prism off by the same amount. Trimble files store distances before it’s applied, so confirm the value matches the prism the crew actually used.

The constant should be applied in one place only: normally the instrument is set to 0 and the prism is picked in the data collector. If the crew set it in the instrument instead, the distances already include it, so enter 0 here. Set in both places, it gets counted twice.

Prism	Shots	Constant (mm)

These constants match the prisms used, and the instrument was set to 0 mm (if the constant was set in the instrument, I entered 0 here)

Elevations

Carried carefully Rough Horizontal only

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Carried carefully: real HIs and rod heights were measured, so elevations are adjusted and checked. Rough: elevations are adjusted but loosely weighted and not flagged hard. Horizontal only: skip elevations.

4Export adjusted coordinates

Basis of these coordinates
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What the coordinates are tied to. Anyone who uses them later needs to know this, so it is written into the notes file too.

Order

PNEZD PENZD

File

.csv .txt

Add "HELD" (or "GPS") to control point descriptions

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Adds HELD (or GPS) to the end of the description for points that were held or tied to GPS, so they stand out in CAD and you can see they didn’t move.

Header row (most CAD imports expect none)

Comma delimited. Keep the notes file with the coordinates so whoever imports them knows what they're tied to.

Closing Angle by Shields Precision

1Upload field data
?
The raw file from your data collector. Carlson / SurvCE: export the job’s .raw (or .rw5). Trimble Access: export JobXML (.jxl). Every angle, distance, HI and rod height is read from it; nothing is changed in your file.

2Control
?
Control is what ties the traverse to the ground: points with known coordinates. A traverse on its own has the right shape but could sit anywhere and point any direction, so it has to be held to something. More in the guide.

3How it was measured
?
Tells the adjustment how good your measurements should be, so it can spread errors fairly and spot shots that are worse than the instrument should allow.

4Export adjusted coordinates

1Benchmarks

2Field book Example — replace with your notes

Get your files

1Upload field data ?The raw file from your data collector. Carlson / SurvCE: export the job’s .raw (or .rw5). Trimble Access: export JobXML (.jxl). Every angle, distance, HI and rod height is read from it; nothing is changed in your file.

2Control ?Control is what ties the traverse to the ground: points with known coordinates. A traverse on its own has the right shape but could sit anywhere and point any direction, so it has to be held to something. More in the guide.

3How it was measured ?Tells the adjustment how good your measurements should be, so it can spread errors fairly and spot shots that are worse than the instrument should allow.

4Export adjusted coordinates

1Benchmarks

2Field book Example — replace with your notes

1Upload field data
?
The raw file from your data collector. Carlson / SurvCE: export the job’s .raw (or .rw5). Trimble Access: export JobXML (.jxl). Every angle, distance, HI and rod height is read from it; nothing is changed in your file.

2Control
?
Control is what ties the traverse to the ground: points with known coordinates. A traverse on its own has the right shape but could sit anywhere and point any direction, so it has to be held to something. More in the guide.

3How it was measured
?
Tells the adjustment how good your measurements should be, so it can spread errors fairly and spot shots that are worse than the instrument should allow.