updated: 26-Nov-2009
Copan for Windows
Field Data Processing
Contents
Use this module to process most raw field survey data
— horizontal and vertical circle readings, slope distances, and instrument and signal heights —
whether concerning many connected traverses, unconnected total station surveys, or combinations thereof, to calculate new points.
Data can come from data logger files or be manually input.
Traverses can be adjusted for misclosure (but see a Bug note below) and new points may be saved.
Note that, intersections, resections, and redundant observations (other than at the end of a traverse) are not handled here.
(For intersections, use the § COGO Calculations module.
For resections, use the § Field Resections Processing module.)
And this module cannot easily be used for azimuth traverses.
(For such needs, use the § Field Bearings Processing module,
the § Map Traverses module,
or the § Map Checks module.)
Also note that, while there are certain similarities between the Map Traverse and the Field Data modules, there are various operational differences (other than the type of map/survey data involved).
If you are familiar with one and new to the other, please study the appropriate manual and dialog carefully.
1. To Process Field Data
- Calculation | Process Field Data...
- Optionally Load... a field data File.
(See § Field Files.)
- Edit data in the big edit box as required.
NB: To move the text cursor:
Use the arrow, Tab, or Enter keys, or the mouse pointer.
To manually insert a tab, copy and paste an existing one.
To go quickly to the beginning or end of your data in the big edit box — especially useful if you have a huge set of data to peruse — use the Home and End buttons, respectively.
- To enter setups and observations data, use the mini edit boxes and the relevant Insert button.
To enter project, instrument and scales data, use the supplementary dialog via the Project-Instrum-Scales.. button.
- Save the Field file for reuse.
- Optionally Delete comments.
- Optionally change the precision of displayed/listed distances and coordinates via Settings....
- Calculate (or OK) to process the field data, adjusting the traverses if appropriate
(see § Traverse Processing and see also a Bug note below).
- To graphically view the shots:
Close the Info Display window if it is open, and
minimize or move aside — but do not close — the Field Data window.
- Optionally List the field Data, the Calcs, or the Points that have been computed.
- Optionally choose whether to Renumber new points or replace existing points
(see § Point Renumbering or Replacement) and
Save the Points that have been computed.
click for larger view
2. Field Data Entry
Setups and Observations Data Entry
-
For each non-traverse instrument Setup (and backsight) — and for the first setup in a traverse — insert the following:
- At # the station point number,
- Either Ref.# the reference (or backsight) point number,
or Ref. Bng. an assumed reference azimuth (or bearing),
- Hor. Circ. the reference horizontal circle value,
- Ht. Instr. the instrument height — if elevations are required.
They stay in effect until a new Setup is inserted.
After a Setup line, multiple side-shots and one traverse leg can appear in any order.
-
For each traverse Setup (and backsight) — except the first —
insert the At #, Ref.#, Hor. Circ., and Ht. Instr.,
-
For each shot Observation, insert the following:
- To # the target point number,
- Hor. Circle the horizontal circle value,
- Vert. Circle the vertical circle value (or zenith angle),
- Slope Dist. the slope distance,
- Ht. Signal the signal (or pogo) height — if elevations are required,
- Code a point code, if needed,
- Note a point note, if needed.
-
For a remote elevation measurement (REM), insert it as an Observation but without a Slope Distance (or possibly also without a Horizontal Circle).
See Remote Elevation Measurement in § Field Files for details.
-
For the last leg of each traverse, be sure to use one of these buttons:
- end open for an open traverse (i.e., ending on an unknown point), or
- end closed for a closed traverse (i.e., ending on a control point or on its initial setup point).
If the last leg of a traverse has not been identified,
Copan may not report results properly.
-
After the end of a traverse, a closing angle Observation may be inserted:
- Either To # the closing target point number,
or Closing Bng. the assumed closing azimuth (or bearing),
- Hor. Circle the horizontal circle value,
- Code if desired,
- Note if desired.
Copan will correct any angular misclosure prior to traverse adjustment.
Project, Instrument and Scales Data Entry
-
Insert any desired Project data, anywhere. Note however, that, along with Instr. ID, such data are ignored during calculations.
-
Insert any Scales or Instrument constants, whenever they differ from their previous values. These are (along with their default values)
- Projection SF (1.0) for map projection distortion — applies only to horizontal distances,
- Units Factor (1.0) for height and distance unit conversion (e.g., feet to metres),
- Dist. Factor (1.0) for slope distance multiplicative correction (e.g., due to extreme temperature),
- Dist. Corr. (0.0) for slope distance additive correction (e.g., prism constant),
- VC Corr. (0.0) for adding to vertical circle values,
and they stay in effect until new ones are inserted.
Be sure to use the proper correction!
In most cases, the default values are appropriate.
A units factor of 3.2808399 is needed if measurements are in metres and coordinates are in feet.
3. Field Files
Copan can read field data in different industry formats as well as its own.
A native Copan field file consists of numerous Setup and Observation data lines and may contain comment lines, as well as Project, Scale, or Instrument data lines, if required.
Each data line consists of various tab-separated attribute = value pairs.
See § Field Files for a description of different raw field file types and Copan's field file format.
4. Field File Examples
In all these examples, codes and notes have been omitted for brevity.
Example 1: 2D closed loop traverse.
A looping traverse can be oriented via an assumed bearing or via an assumed control point.
Here's a traverse, oriented with an assumed azimuth of 180.
at= 509 az= 180.0000 HC= 0.0000
to= 508 HC= 270.2051 VC= 90.0000 SD= 244.260
at= 508 ref= 509 HC= 0.0000
to= 507 HC= 284.3940 VC= 90.0000 SD= 189.115
at= 507 ref= 50 HC= 0.0000
to= 506 HC= 164.5417 VC= 90.0000 SD= 179.562
at= 506 ref= 507 HC= 0.0000
to= 505 HC= 270.3249 VC= 90.0000 SD= 195.591
at= 505 ref= 506 HC= 0.0000
to= 509 HC= 269.3231 VC= 90.0000 SD= 362.140
end= closed
at= 509 ref= 505 HC= 0.0000
az= 180.0000 HC= 360.0000
Here's the same traverse, oriented with reference to a dummy point 999, which has been placed due south of the start.
at= 509 ref= 999 HC= 0.0000
to= 508 HC= 270.2051 VC= 90.0000 SD= 244.260
at= 508 ref= 509 HC= 0.0000
to= 507 HC= 284.3940 VC= 90.0000 SD= 189.115
at= 507 ref= 50 HC= 0.0000
to= 506 HC= 164.5417 VC= 90.0000 SD= 179.562
at= 506 ref= 507 HC= 0.0000
to= 505 HC= 270.3249 VC= 90.0000 SD= 195.591
at= 505 ref= 506 HC= 0.0000
to= 509 HC= 269.3231 VC= 90.0000 SD= 362.140
end= closed
at= 509 ref= 505 HC= 0.0000
to= 508 HC= 270.2051
Example 2: 3D linear traverse.
Here's a linear traverse, with the end point as an unknown.
at= 144 ref= 519 HC= 0.0000 HI= 1.648
to= 38 HC= 59.3848 VC= 89.1506 SD= 190.160 HS= 1.583
at= 38 ref= 144 HC= 0.0000 HI= 1.583
to= 39 HC= 152.1009 VC= 83.1043 SD= 90.118 HS= 1.553
at= 39 ref= 38 HC= 0.0000 HI= 1.553
to= 36 HC= 192.5206 VC= 86.0415 SD= 84.178 HS= 1.483
at= 36 ref= 39 HC= 0.0000 HI= 1.483
to= 198 HC= 232.5554 VC= 86.2758 SD= 111.153 HS= 1.510
end= open
Here's the same traverse, with the end point as control.
at= 144 ref= 519 HC= 0.0000 HI= 1.648
to= 38 HC= 59.3848 VC= 89.1506 SD= 190.160 HS= 1.583
at= 38 ref= 144 HC= 0.0000 HI= 1.583
to= 39 HC= 152.1009 VC= 83.1043 SD= 90.118 HS= 1.553
at= 39 ref= 38 HC= 0.0000 HI= 1.553
to= 36 HC= 192.5206 VC= 86.0415 SD= 84.178 HS= 1.483
at= 36 ref= 39 HC= 0.0000 HI= 1.483
to= 198 HC= 232.5554 VC= 86.2758 SD= 111.153 HS= 1.510
end= closed
Here's the same closed traverse, with a closing angle.
at= 144 ref= 519 HC= 0.0000 HI= 1.648
to= 38 HC= 59.3848 VC= 89.1506 SD= 190.160 HS= 1.583
at= 38 ref= 144 HC= 0.0000 HI= 1.583
to= 39 HC= 152.1009 VC= 83.1043 SD= 90.118 HS= 1.553
at= 39 ref= 38 HC= 0.0000 HI= 1.553
to= 36 HC= 192.5206 VC= 86.0415 SD= 84.178 HS= 1.483
at= 36 ref= 39 HC= 0.0000 HI= 1.483
to= 198 HC= 232.5554 VC= 86.2758 SD= 111.153 HS= 1.510
end= closed
at= 198 ref= 36 HC= 0.0000
to= 265 HC= 127.4300
Example 3: 3D closed loop traverse with side-shots.
Notice that side-shots may precede leg-shots (e.g., 3 and 8)
or they may follow leg-shots (e.g., 6 and 8).
at= 1 az= 351.3825 HC= 0.0000 HI= 1.515
to= 3 HC= 173.5504 VC= 88.1644 SD= 28.010 HS= 1.280
to= 5 HC= 100.2213 VC= 94.3117 SD= 62.271 HS= 1.280
at= 5 ref= 1 HC= 0.0000 HI= 1.510
to= 7 HC= 77.0519 VC= 88.5648 SD= 61.888 HS= 1.280
to= 6 HC= 94.0147 VC= 93.4530 SD= 17.208 HS= 1.280
at= 7 ref= 5 HC= 0.0000 HI= 1.567
to= 8 HC= 226.5026 VC= 107.5427 SD= 20.437 HS= 1.280
to= 2 HC= 96.1240 VC= 90.1123 SD= 58.458 HS= 1.660
at= 2 ref= 7 HC= 0.0000 HI= 1.660
to= 1 HC= 86.1954 VC= 86.2230 SD= 54.495 HS= 1.515
end= closed
to= 9 HC= 73.5238 VC= 92.4451 SD= 19.872 HS= 1.510
at= 1 ref= 2 HC= 0.0000 HI= 1.515
az= 351.3825 HC= 360.0000
Example 4: 3D topo survey with REM points.
Notice that a REM point may be before (515) or after (507) its base point.
at= 1 ref= 5 HC= 00.0000 HI= 1.614
to= 506 HC= 60.2550 VC= 79.4345 SD= 7.048 HS= 1.418
to= 507 VC= 64.3500 bas= 506
to= 515 VC= 70.4040 bas= 516
to= 516 HC= 25.1415 VC= 86.1720 SD= 11.581 HS= 1.418
5. Notes
- If you need to manually insert a tab, such as when you wish to add a code or remark to an observation line, copy and paste an existing tab — there will always be one between two auto-inserted attribute=value pairs.
- Currently, heights are carried forward, from the known setup to a target, not from a known reference to the setup. To do the latter, you need to trick Copan by manually converting the trigonometric height observation from a backward to a forward form (i.e., switch the HI and HS, and suplement the VC).
- Both negative and zero values for HI or HS are correctly interpreted.
- When a setup point's elevation value is missing (or null), Copan does not use any rises to targets (i.e., target elevations will be null).
- Also, a missing HI or HS yields a null rise and a null target elevation.
6. Bug
Although Copan can process multiple traverses in a single field data file, there is a bug in how it adjusts dependent traverses,
i.e., any traverse that begins on an intermediate station of an earlier traverse in the file.
Suppose, for example, you have two traverses in a field file.
The first (the primary traverse) is a closed connecting traverse, and the (secondary) traverse starts on an intermediate point along the first traverse.
If you adjust the primary traverse, the secondary traverse will be computed as if the first were not adjusted —
even though the second traverse is reported to begin from its adjusted position.
The proper work-around, until this bug is fixed, is to split the field file into primary and secondary field files, run and adjust the primary traverse in one field file, then run the secondary traverses in a separate field file.
If you have multiple independent traverses, i.e., no traverse starts from an intermediate traverse point, then there is no problem — they can all be run and adjusted from the same field file.
updated: 26-Nov-2009