Survey Grade GPS Resources

CSV to DXF converter

Sep 15, 2012 by daikini

A csv2dxf commandline tool allows you to convert csv file into a simple DXF sketch.

Trimble online file conversion

Feb 10, 2012 by daikini

For some time Trimble shares online conversion service which allows you to convert *.job and *.sty files between different versions of Survey Controller software.

Service is written with MS Silverlight framework so you need to install plugin for your internet browser.

Ashtech geoid models support

Feb 7, 2012 by daikini

Ashtech released user friendly google maps based geoid model support. You can download available models just by clicking on the world map and choose from among several models made for individual countries or from the fragments of global model EGM 2008. With GEOID EXTRACT TOOL you can easily crop a geoid separation file to the sole area.

Models may be used not only with Fast Survey but also with Carslon SurvCE and it's free alternative for paid and not quite competent Carlson XPort software.

Here's EGM2008 geoid separation file for area of Poland, compatible with Carlson Survce field software.

EGM2008 undulations calculation

Feb 4, 2012 by daikini

Allsat released AllTrans EGM2008 Calculator. This utility calculates EGM2008 geoid undulations for given coordinates using four methods of interpolation:

  • BiQuadratic
  • Bi_linear
  • Triangualtion
  • Nearest Neighbour

By default software uses internal model based on a 10'x10' grid. For better accuracy 1' x 1' model can be downloaded from U.S. National Geospatial-Intelligence Agency site.

Dilution of precision

Feb 1, 2012 by daikini

Requires Java 1.02 or better. Use this applet to learn how the geometry of the visible GPS satellites effect the accuracy of your GPS, as indicated by the DOP values. This demonstration allows you to put satellites anywhere, even in positions where you would never see them at your location, even in geometries which can not occur with the current GPS satellite constellation. The EPE value given after the DOP values is the DOP value times 32 meters.

Your browser is not Java enabled.

Credits: The MIT matrix routines are used in this program. Please report bugs, quirks, errors and omissions to