How to remove date, time and speed from GPS track ?

EricGagneEricGagne Global Mapper UserPosts: 129Trusted User
edited July 2015 in Technical Support
Using GM 14.2.

I have nearly 5000 km of GPS Tracks and I need to remove the date, time and speed from them. Is there a way to remove these or convert those line to "normal" line features ?


  • EricGagneEricGagne Global Mapper User Posts: 129Trusted User
    My question has not been answered in 5 days and I see many topics started in the last 2 or 3 weeks that are still unanswered as well ?

    Is the forum still monitored by GM people ? Should I contact support directly instead ?
  • PhilRatcliffePhilRatcliffe Global Mapper User Posts: 27Trusted User
    Hi Eric, try either opening the file as an ASCII Text & deleting unwanted columns, or export from GM to ASCII & do the same. Hope that helps
  • EricGagneEricGagne Global Mapper User Posts: 129Trusted User
    Phil thanks for the idea. GPX files are actually xml data so it is not easy to remove a column and GM's export to CSV only exports points.

    But your sugestion gave me an idea. In GM I exported my tracks to KMZ, opened the file I just created and that's all there was to it. All timestamps are gone :smiley:

    Thx again !
  • PaulTocknellPaulTocknell Forum Administrator Posts: 307
    edited July 2015
    The forum is still monitored by GM people (frequently) but they do not always have the bandwidth to address each question and discussion. The idea, hopefully, is that as a GM community, we are able to support each other. That is my goal as the admin of the community is to create a culture of community support. Thank you @PhilRatcliffe for your contribution and assistance.

    As a sidenote, Blue Marble has pledged to offer some tangible rewards to those who contribute to the Global Mapper community. Those rewards are still be negotiated and discussed internally but hopefully I can announce something publicly shortly.
  • EricGagneEricGagne Global Mapper User Posts: 129Trusted User
    Thanks Paul,

    I was wondering because we used to get answers within hours. I guess Mike spoiled us a bit :smile:
  • EricGagneEricGagne Global Mapper User Posts: 129Trusted User
    Still a problem with this. My lines have been edited a few times, the feature types were changed to custom ones and they were also moved from layers to layers.

    As a result, some of them have the name of a previous feature type in the Feature Description. The problem is that this description is what is exported to KMZ and is used as the feature type when I open that KML.

    So the exporing to KMZ and opening that file does get rid of the timetamps but many of my lines no longer have the correct type.

    How do I change the feature description in GM ? I see it as a column in the results window when I searched features but I find no place where I can edit or empty it.
  • EricGagneEricGagne Global Mapper User Posts: 129Trusted User
    edited July 2015
    Problem fixed. When exporting to KMZ I selected the Custom option in Feature Descriptions and put %<Feature Type>% in the text box.

    That forced the feature type to be used as feature description in KML and when reopening the file, all my lines are good and the <Feature Type> and <Description> attributes are synced

  • MykleMykle Global Mapper User Posts: 448Trusted User

    (noted that you are using version 14.2, thanks)

    You may have more flexibility by using a spreadsheet program alongside Global Mapper. You should be able to export your tracks to a CSV file. This file will hold the coordinates of your trackpoints, and if you have included attributes in the file then one or more of them may identify the track of which that point is a part. You should also have an attribute that orders the points within each track, perhaps as time, perhaps as an integer.

    Note that this says that you can have points from multiple lines in one CSV file, as long as you have included an attribute to associate each point with the appropriate line. When you import the file into Global Mapper, ensure that you identify the column number that includes your line/track name.

    Excel, for example, will open a CSV file. If it does not parse the records into columns, but holds the entire record in the first column, then you can mark the first column and use the Text-to-column function to parse by the tab characters (or other separator like a comma) so you have several columns of values.

    Working with this file in a spreadsheet allows you to sort by track name and sequence, add and delete columns, add and delete points, and so on. ENSURE THAT YOUR FIRST RECORD HOLDS NAMES FOR EACH COLUMN. This is helpful (if not required) within Global Mapper when selecting columns for display or analysis.

    While you can save your work as a CSV file, my work normally requires data to be in a text file, so I will save the file as a spreadsheet file (XLS) and copy-and-paste the content into a text file of the same name. CSV and TXT files are easily imported into GM.

    Note that you can choose to import these files as points or lines (I'm not familiar with importing areas from these file types - but areas can be created from the lines after import). I will usually import these files twice (ignoring the pop-up message on the second import that tells you what you already know ;-). The files are imported once as points, and once as lines by specifying which column contains the track name (otherwise you wind up with one line for all tracks, and useless segments connecting the end of one track with the beginning of the next).

    Also note that when importing lines GM will use the points in the order read from the file. Ensure that you have sorted the data appropriately within the spreadsheet before exporting your data. We assume that your data includes an attribute that could be used for sorting, or for calculating a value that could be used for sorting.

    If you choose, you can use GM to simplify your track points without losing detail. Set the relevant parameters to those that work for you.

    Exporting to KMZ is simple, as you have found out. You do have unique functions within Google Earth, so that program is useful for more than simple viewing. So, the spreadsheet, Global Mapper, and Google Earth are all tools at your disposal. You get to figure out which ones are easiest to use and accomplish what you like.

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