Copan for Windows
Field Bearings Processing
Use this module to process raw field data from hand-held survey instruments such as compass, inclinometer and rangefinder.
Copan can process the data — azimuths (or bearings), vertical angles, slope distances, and instrument and signal (or target) heights —
whether concerning one or more connected traverses, independent radial surveys, or combinations thereof, to calculate new points.
Data may come from data logger files or be manually input from field books.
Traverses may be adjusted for coordinate misclosure and new points may be saved.
Note that ordinary total station data, intersections, resections, and redundant observations (other than at the end of a traverse) are not handled here.
(For ordinary field data, use the § Field Data Processing module.
For intersections, use the § COGO Calculations module.
For resections, use the § Field Resections Processing module.)
And this module is best for raw, field traverses with slope distances, not for reduced, map traverses with horizontal distances.
(For such needs, use the § Map Traverses or § Map Checks modules.)
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 Bearings
Calculation | Process Field Bearings...
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 enter setups and observations data, use the mini edit boxes and the relevant Insert button.
To enter project, instrument and scales data (such as magnetic-grid north correction), use the supplementary dialog via the More data button.
Optionally Export.. the Field data file in (the BitWise Ideas survey network least-squares adjustment program) GeoLab IOB format.
Save the Field file for reuse.
Optionally change the precision of displayed/listed distances and coordinates via Settings....
Optionally Scale extended-code sizes. This will scale any observation P-codes that are sized according to the rules in § Point Codes by a Units Factor you have set.
Calculate (or OK) to process the field data, adjusting the traverses if appropriate
(see § Traverse Processing).
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 Bearings Entry
Setups and Observations Data Entry
For each instrument Setup insert only the following:
They stay in effect until a new Setup is inserted.
After a Setup line, multiple side-shots (or ties) and one traverse leg can appear in any order.
- At # the station point number,
- Ht. Instr. the instrument height — if elevations are required.
For each shot Observation (whether a traverse leg or a radial point), insert the following:
- To # the target point number,
- Bearing the bearing value (or a bearing expression),
- Vert. Circle the vertical circle value (or zenith distance),
- 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,
- Name a point name, 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 shot of each traverse, be sure to use one of these buttons:
If the last leg shot of a traverse has not been so identified,
Copan may not report results properly.
- 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 the traverse's initial setup point).
Project, Instrument and Scales Data Entry
Keep these three types of data on separate lines:
Be sure to use the proper correction.
In most cases, the default values are appropriate.
Insert any desired Project data (Job, Date, Time, Surveyor, Field book, or Pages) wherever convenient.
Note, however, that such data are ignored during calculations.
Insert any Instrument constants, whenever they differ from their previous values. These are (along with their default values)
and they stay in effect until new ones are inserted.
- Instr. ID () ignored during calculation,
- Azim. Corr. (0.0) for adding to azimuth (bearing) values (e.g., magnetic to grid),
- VC Corr. (0.0) for adding to vertical circle values,
- Dist. Corr. (0.0) for slope distance additive correction (e.g., prism constant),
- Dist. Factor (1.0) for slope distance multiplicative correction (e.g., due to extreme temperature),
Insert any Scales, whenever they differ from their previous values. These are
and they stay in effect until new ones are inserted.
- Scale Factor (1.0) for combined map projection and sea-level (or elevation) distortions — applies only to horizontal distances,
- Units Factor (1.0) for height and distance unit conversion (e.g., feet to metres),
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, Instrument or Scales data lines, if required.
Each data line consists of various tab-separated attribute = value pairs.
See § Field Files for a more detailed description of different raw field file types and Copan's field file format.
4. Field Bearings File Example
In this example, a two-leg, closed traverse with side-shots is preceded by an azimuth correction, and codes and notes have been omitted for brevity.
at= 382 HI= 1.55
to= 800 az= 235.42 VC= 90.18 SD= 4.6 HS= 1.58
to= 801 az= 226.06 VC= 90.24 SD= 22.2 HS= 1.58
to= 802 az= 219.54 VC= 90.48 SD= 25.6 HS= 1.58
to= 804 az= 229.30 VC= 90.36 SD= 24.6 HS= 1.58
at= 804 HI= 1.55
to= 805 az= 194.00 VC= 90.36 SD= 35.0 HS= 1.58
to= 806 az= 134.18 VC= 90.06 SD= 7.8 HS= 1.58
to= 807 az= 129.54 VC= 90.18 SD= 17.8 HS= 1.58
to= 387 az= 133.00 VC= 89.36 SD= 31.0 HS= 1.58
While repetition and redundancy are common in field surveying, Copan can only process simple traverses consisting of reduced observations. Multiple sets of observations of the same quantities and cross-ties cannot be processed without some manual editing.
For example, prior to processing, repeated sets of angles and distances must be averaged and check shots to the same points from different setups must be renumbered.
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.
When you Calculate, Copan always checks and computes the field data currently in the big edit box.
Changes to field data in the big edit box are only saved (to disk) when you Save Data.
Elevations 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.
Newly calculated points are not saved to the coordfile until you click Save Points.
When you Save Points, Copan first creates an automatic backup copy of the coordfile.