updated: 24-Mar-2011

Copan for Windows

Field Data Processing

Contents

Process Field Data
Field Data Entry
Field Files

Field Data File Examples
Notes

Use this module to process raw field data from survey instruments such as total station, or theodolite and EDM. Copan can process the data — horizontal and vertical circle readings, slope distances, and instrument and signal (or target) heights — whether concerning 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 with redundant angles will have angles balanced. Closed traverses may have their coordinates adjusted for misclosure and new points may be saved.

Note that intersections, resections, freestations, and redundant observations (other than at the end of a traverse) are not handled here. (For intersections, use the § COGO Calculations module. For freestations, use the § Field FreeStations Processing module.) And this module cannot easily be used for map traverses. (For such needs, use the § Field Bearings Processing, § 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 Data

From the Calculation menu, choose 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.
Optionally Export.. the Field data file in (the BitWise Ideas survey network least-squares adjustment program) GeoLab IOB format.
Save the Field data file for reuse.
Optionally Delete comments.
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 Data Entry

Setups and Observations Data Entry

For the first instrument Setup (and backsight) in a traverse — and for each non-traverse setup — 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 (or ties) and one traverse leg shot can appear in any order.
For each traverse Setup (and backsight) — except the first — insert
- At # the station point number,
- Ref.# the reference (or backsight) point number,
- Hor. Circ. the reference horizontal circle value,
- Ht. Instr. the instrument height — if elevations are required.
For each conventional shot Observation (whether a traverse leg or a radial point), 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 (target, prism, reflector, 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:
- 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).
If the last leg shot of a traverse has not been so 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), and
- Hor. Circle the horizontal circle value.
- While you may include a Code, Note or Name here, they will be ignored.
Copan will correct any angular misclosure, by distributing the error equally among the setups, prior to traverse adjustment.

Enter Project, Instrument, or Scales data and click Insert.

Project, Instrument and Scales Data Entry

Keep these three types of data on separate lines:

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)
- Instr. ID () ignored during calculation,
- 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),
and they stay in effect until new ones are inserted.
Insert any Scales, whenever they differ from their previous values. These are
- 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),
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.

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 Scale 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 Data File Examples

In all these examples, codes, notes and names 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 (i.e., an open traverse).

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 (i.e., a connecting traverse).

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 (or ties) 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 topographic survey with REM points.

Notice that a REM (remote elevation measured) 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

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 note 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.

updated: 24-Mar-2011