IMAGIS Education

IMAGIS Classic

QuickStart and Input & Output Formats

The following instructions are aimed at quickly familiarizing the experienced ArcInfo user with DEMix.

Start ArcInfo (Windows 98 or NT versions only) and type the following at the Arc command prompt. There are two cases to be discussed: 

1. For a single coverage map: 

      Arc> path\DEMix Genpt <ArcInfo terrain coverage pathname> <contour interval>
      <DEM Interval X> <DEM Interval Y> <product directory>
      <waterbody shoreline coverage pathname>

      Explanation, comments and examples about the above command line:

• Genpt: Generate structure line points from the input data from one map sheet. 
• ArcInfo Terrain Coverage path: Include the full path with directories separated with a backslash (\).
  If your map includes several coverages, separate them using a comma (,).
  For example: If your coverage is located in d:\maps\terlk0
  You must type in the command: 
  DEMix genpt d:\maps\terlk0
  If your coverages are located in d:\maps\terlk0 and d:\maps\terlk1 , you must type in the command:
  DEMix genpt d:\maps\terlk0, d:\maps\terlk1
• Contour interval (float): Input the contour interval: if none is provided, the default value is 1.0m
• Dem Interval X (float): Input the DEM interval in the X direction: if none is provided, the default value is 10.0m
• Dem Interval Y (float): Input the DEM interval in the Y direction: if none is provided, the default value is 10.0m
• Product Directory: Type in the name of the directory into which the output DEM will be placed. The default directory is the same as for the input coverage and the product name will be "DEMix".
  Example:
  If your coverage is d:\maps\terrain
  Then the default product directory will be d:\maps\DEMix
• Waterbody shoreline coverage name: Within this area the terrain height is the same. If there is no such coverage, simply hit <Enter>

2. For batch processing a number of multiple coverage maps: 

      Arc> path\DEMix Batch <batch par file>

• Batch: Batch processing your multiple coverage maps.
• batch par file: Your multiple coverage map sheets file.

      In this case, the user has to create a batch par file (*.txt) with two header lines followed by the parameters of the individual map definition:
      First header line: the file flag for batch processing: 
      DEMIX_GENCN_BATCH
      Second header line: Total number of maps to be processed, e.g. 

3.Thereafter follows 5 lines for each map definition:

• Line 1: Terrain coverage pathname
• Line 2: Contour interval, DEM X, DEM Y,
• Line 3: Product path 
• Line 4: Waterbody shoreline coverage pathname or "Enter".
• Line 5: Flag for the automatic deletion of the temporary directory storing the iteration results. The flag must be either "0" - not deleted, or "1" - deleted automatically (without the quotes).

Note: The format of the batch processing file must be strictly adhered to. 

Example: (In the third map, because the water system doesn't exist, in this line there is only an "Enter"). 

DEMIX_GENCN_BATCH 
      3 
      d:\Maps\ K516800\Terlk. 
      10 20 20 
      d:\Maps\ K516800\Wtlnt 
      d:\Prods\K516800 
      1 
      d:\Maps\ K516801\Terlk 
      5 10 10 
      d:\Maps\ K516801\Wtlnt 
      d:\Prods\K516801 
      1 
      d:\Maps\ K516802\Terlk 
      1 10 10 
      "Enter" key 
      d:\Prods\K516802 
      1 

Comments:

• When using Batch mode, there is no interface/dialog
• Your coverage must contain all the appropriate files, e.g. "pat.dbf", "arc.dbf", "tic.dbf", etc. If these files do not exist in your coverage, the system produce an error. You can create a batch command using ArcInfo's AML to generate these files if necessary.

Output: The software will produce the following products: 

1. The structure points data files ("StructPt.txt" and "Structln.txt"). The structure points file is nothing more than a coordinate list in ArcInfo's Generate ASCII Format. The first column is the Z value followed by X and Y. 
   Comments: 

• The Z value has been multiplied by 100 (no float for Z in ArcInfo);
• The file "Structln.txt" contains the X and Y structure line coordinate information and can be directly read by ArcInfo. The Z values are assigned as "-9999". This file is important for checking the quality of the input data. In general, if errors exist in the input data, they will be able to be identified using "Structln.txt".

2. DEM (DemGrid.txt): The format of the DEM file is ArcInfo Grid ASCII. It can be imported into ArcInfo using the command "ASCIIGrid "
3. Quality control report (report.txt):

• Root mean square errors (float, in meters)
• Z_error's distribution (Z_error = Z value of contour points interpolated from the DEM from DEMix - the Z value known from the input data)
• The position table depicting which values of Z_error are larger than one third of a contour interval

4. Error File (errorpos.txt): This file contains the Z, X and Y coordinates of all the points whose displacements are larger than 10m. It is used to describe the displacement of the input contour lines from the "new" contour lines generated from the DEM from DEMix. 

DEMix Input Data Formats

      At this stage, DEMix can only read ArcInfo coverages in dBase format. If your ArcInfo coverage has not been saved in dBase format, it can be converted using the command "Infodbase". DEMix reads the Lab and Arc data from the coverage so ensure that these files exist before invoking DEMix. 

      DEMix also reads the following files: 

• ARC.ADF, ARX.ADF
• PAX.ADF, PAL.ADF
• LAB.ADF
• AAT.DBF
• PAT.DBF

      If you receive a system error such as "File open error" you should check your coverage to ensure that these files exist or that the disk is not full. 

      How to Export DEMix Data to ArcInfo: The output format of the DEMix files like "structpt.txt" , "errorpos.txt" is in points format of ArcInfo and the file "structln.txt" is in lines format of ArcInfo, you can output it into ArcInfo by command "generate" . 

Examples:

      Consider a coverage called "ter" and stored in "c:\ter". Save the coverage in dBase format: 

      Arc: INFODBASE ter.AAT c:\ter\AAT.DBF
      Arc: INFODBASE ter.PAT c:\ter\PAT.DBF
      Arc: INFODBASE ter.TIC c:\ter\TIC.DBF

      Input the result from DEMix to ArcInfo (if the DEMix output is " c:\ret\structpt.txt ", it will generate the "str_pts" coverage):

      Arc: generate str_pts
      generate : input c:\ret\structpt.txt
      generate : points
      generate : q
      Arc: build str_pts point
      Arc: additem str_pts.pat
      Arc: str_pts.pat altitude 8 12 n 2
      Arc: tables
      Enter Command: select str_pts.pat
      Enter Command: calculate altitude = str_pts-id / 100
      Enter Command: calculate str_pts-id = 0
      Enter Command: q
      Arc: idedit str_pts point