Importing Raw Field Data

Converting raw field data from survey to an Arc/Info coverage

This is a description of how to convert files from the RC Survey department to Arc/Info coverages.

First, you get a 3.5" floppy disk of field data from the Survey department. The PC floppy disk will contain a series of files that end in the extensions .dat (data files) and .con (control points).

Put the floppy into the floppy drive and either use the File Manager under the File pulldown menu to select Check For Floppy, or type at the prompt:

	Landinfo1%  volcheck

Create a directory with mkdir (with the name survey if it doesn't already exist) and copy all the the files from the floppy to that directory. For example:

	Landinfo1%  cd
	Landinfo1%  mkdir survey

	Landinfo1%  cd survey
	Landinfo1%  cp /floppy/floppy0/*.* .

You can eject the disk either by pressing Eject Disk in the Floppy window or:

	Landinfo1%  eject

Then use the dos2unix command to get rid of the DOS ctrl-M's (linefeed) and ctrl-Z's (End-Of-File Marker) which are unnecessary in UNIX.

	Landinfo1%  dos2unix 247958.dat data
	Landinfo1%  dos2unix 247958.con control

(we execute dos2unix using the file 247958.dat as input and output the results to a new file called data)

After converting the files into UNIX format, create a new file raw using cat to concatonate the file control with the file data and put the results into the new file raw.

	Landinfo1%  cat control data > raw
	Landinfo1%  vi raw

We need to add in the Northing (26) and Easting (38).

	:1,$s/37=/37=26/g
	:1,$s/38=/38=38/g

Next, we change from the condensed format by converting the spaces to newlines with the command:

	:1,$s/ /{control-v}{control-m}/g

(note: the bracketed {control-v} means press both control and v. The space is necessary. This takes lines 1 to the end of file and swaps each space with ^M globally in each line.)

The resulting screen should show only one item per line. Save the file and quit vi with:

:wq

Start Arc, set the precision to double, and show the usage of the fdconvert command.

	Arc:  precision double

	Arc:  fdconvert                (fdc is abbreviation)
	Usage: FDCONVERT <in_observation_file> <out_fielddata_file>
			 <SOID | GEODIMETER | LIETZ | WILD>
			 {in_coordinate_file | in_lookup_table}

For example:

	Arc:  fdconvert raw gff GEODIMETER

	Converting Geodimeter Geodat 400 format to ESRI Generic
	 Fielddata Format...
	Input observation file :  raw
	Output fielddata file  :  gff

This process returns a new file (gff) in ESRI's Generic Fielddata Format.

Now, run the command fielddata with your AML if you made one or enter the values below by hand to set up your coverage files and attribute values used as parameters by the fielddata command.

	Arc:  fielddata                (fd is abbreviation)
or
	Arc:  fielddata gff.aml        (if gff.aml already exists)

You can make an AML file (example was gff.aml) containing fielddata commands:

	ERRoraction IGNORE
	ZITEM z
	PointITEM pointid ALPHA 10
	DescriptionITEM descrip 4
	CoordinateForMaT xyz
	AVeraging OFF
	AngleUNIT DMS
	PointCOVerage pnt
	File gff
	Quit

There should be a series of messages on the screen about creating coverages and checking the data. The result will be the point coverage pnt listed in the AML script above.

Note: if the aml is used, the FILE gff should match the one used in the fdconvert command prior.

Now you should have an arc coverage called pnt You create the arc coverage lin using the extents of pnt with:

	Arc:  createcogo arc lin pnt

Now add the Location Identification Code Number (licn) to the COGO point (pnt.pat) and COGO arc (lin.aat) coverages. The licn item will be a double float with no decimal places.

	Arc:  additem pnt.pat pnt.pat licn 8 13 f 0
	Arc:  additem lin.aat lin.aat licn 8 13 f 0

Then start Arcedit, open a display and start with either cogomenu or cogoenv

	Arc:  ae
	Arcedit:  cogomenu
or
	Arcedit:  cogoenv lin pnt

You will want to set-up your cogo environment to azimuth and display pointid.
You may wish to set the cogopointnumber to 100 as well (cpn 100) before starting.
This may be unnecessary, as lcd build AML (blcd.aml) will deal with the inbetween points of its own.

Additional LCD creation notes (per Rodrigo Santos)

The order of precedence to follow when generating lines for a LCD are:

Distance measurments from the surveyor's field notes
An outside building corner
An inside building corner or wall point

The maxmum wall width is 30 cm and minimum is 15 cm.
Use the minimum width of a wall, (.15 or .16) so the middle is .075 (or .8)
The error standard used for distance between actual and LCD is 0.02 m.
The error standard used for lot area between actual and LCD is 0.25 sq m.

Author: Paul Bailey
Modification: CH, 9 Nov 96
Chris Hanson (html 14/11/96)