-->
header image

Collection of AutoLisp for Survey Utilities - Lisp Help

Under Survey Utilities, draw grid, snap text to nearest point the grid, find lat long of selected text, do traverse correction, and represent sea-leavel type elevation representation.

SURVEY UTILITIES COMMANDS

 

Sl. No.

Command

Description

1 DGRID To draw grid with given grid interval
2 SNP To snap text to nearest point on the grid with given grid spacing
3 FLL To show the lat long of a selected point
4 BXT To put box around text
5 TC To traverse correction
6 PCT To paste clean text
7 SEA To set sea-level type elevation representation for text and block
1. DRAW GRID WITH GIVEN GRID INTERVAL (DGRID)

Menu: Draw grid with given grid interval (DGRID).

Functionality: To draw the grid with given grid interval.

Description: A grid is a pattern of parallel lines intersecting at right angles and forming squares or rectangles. It is used to identify precise positions, to help you locate a position accurately on the surface of the earth or map sheet. Using ‘DGRID’ command, grid lines can be drawn easily at any required interval. ‘DGRID’ will also annotate all the grid lines with respect to its Easting and northing.

Procedure:
  • Type ‘DGRID’ at the command prompt
  • Lower Left corner: Select the lower left corner to draw the grid.
  • Top Right corner: Select the top right corner of the grid to be imported.
  • Type the Interval: Enter the grid line spacing between two successive grid lines.
Survey Utilities DGRID Lisp
                                               Draw grid with given grid interval (DGRID)

2. SNAP TEXT TO NEAREST POINT ON THE GRID WITH THE GIVEN GRID SPACING (SNP)

Menu: Snap text to nearest point on the grid with the given grid spacing (SNP)

Functionality: To snap the selected point to the nearest point on a line or a grid falling within the specified snap value.

Description: Using ‘SNP’, the selected texts are moved to grid point of a given grid interval value. Let us say there is a text at easting 100.234 (X) and northing 94.987 (Y), the nearest grid point for interval value of 5 is easting 100 and northing 95. By using ‘SNP’ command all the selected texts can be snapped to their respective nearest grid points.

Procedure:
  • Type ‘SNP’ at the command prompt
  • Type the Snap Value: Enter the value (distance) for which the text is to be snapped to the nearest grid/ line.
  • Select Objects: Select all the text objects that are to be snapped.
Survey Utilities SNP Lisp
                            Snap text to nearest point on the grid with the given grid spacing (SNP)

3. LAT LONG OF A SELECTED POINT (FLL)

Menu: Lat Long of a selected Point (FLL)

Functionality: To show the Lat Long of a selected Point. You need to set the datum, hemisphere and zone before selecting the point.

Description: Survey drawings are represented with coordinate system. Our globe is spherical and it is more precise when represented with Latitude and Longitude. To find out the Lat / Long of a given co-ordinate ‘FLL’ command can be used. You need to set Datum, hemisphere and Zone of the drawing to find the Lat / Long.

Procedure:
  • Type ‘FLL’ at the command prompt
[Note: When you run the application for the first time, it will open up a window where you need to specify the Datum, Hemisphere and Zone and then click on set button. If you further wish to change the Datum or Hemisphere or Zone, use SDS Command]
  • Pick  a point for Lat Long Values: Click a point where you wish to find out Lat / Long Value.
Survey Utilities FLL Lisp
                                                     Lat Long of a selected Point (FLL)

4. PUT BOX AROUND TEXT (BXT)

Menu: Put Box around Text (BXT)

Functionality: To put box around text.

Description: This option is used to put box around selected texts.

Procedure:
  • Type ‘BXT’ at the command prompt.
  • Select entities: Select text entities to draw the box around them.
 Survey Utilities BXT Lisp
                                                              Put Box around Text (BXT)

5. TRAVERSE CORRECTION (TC)

Menu: Traverse Correction (TC)

Functionality: To correct the traverse and give details of calculation.

Description: Description about traverse correction can be found in Interface chapter

Procedure:
  • Type ‘TC’ at the command prompt
  • Type of traverse - Open / <Closed>: Mention Open or Closed Traverse
  • Select the Polyline: Pick the Polyline for which traverse correction has to be done
  • Transit / Bowditch / <Crandall>: Specify the calculation method to be used
  • Pick a Point: Click a point to create the calculation details table.
Survey Utilities TC Lisp
                                                              Traverse Correction (TC)

6. PASTE CLEAN TEXT (PCT)

Menu: Paste Clean Text (PCT)

Functionality: To create new set of elevations ensuring maximum of only one level at a given point.

Description: When point data is collected from various total stations, it may so happen that at same easting and northing there may be two or more elevations. Using such overlapping data if you try to triangulate or generate contours then triangulation may not be possible as there will be multiple levels in same easting and northing and the program will not be able to make out which data to be used. For that reason, you  need to process the data and clear extra point at a specific x, y. Using PCT command you can clear extra points and paste clean text.

Procedure:
  • Type ‘PCT’ at the command prompt.
  • Select entities: Select text which has to be cleaned.

7. SEA-LEVEL TYPE ELEVATION REPRESENTATION OF TEXT AND BLOCK (SEA)

Menu: Sea-level type Elevation Representation of Text and Block (SEA)

Functionality: To represent Sea-level type Elevation representation for Text and Block.

Description: Representation of Survey data on ground and in Sea differs. We represent elevations as 134.56 in ground where as same data say -3.45 (Elevation in Sea) then it is represented as -3 and 45 as two different text. Using ‘SEA’ command normal elevations can be converted as labels which represent sea level.

Procedure:
  • Type ‘SEA’ at the command prompt.
  • Type of entity to be created Text (<T>) or Attribute (A): Specify if text or attribute.
  • Select entities: Select the text or attributes for the operation.
Survey Utilities SEA Lisp
                                Sea-level type Elevation Representation of Text and Block (SEA)