Global Mapper v25.0

Flight date/GPS Time LiDAR

I'm looking for a way to figure out the exact date the LiDAR was flown when I get public LiDAR from the internet. I need to know if there was snow on the ground. When I upload a LAZ file into Global Mapper and select Metadata it will tell me 'Flight_Date". Is this the actual date the LiDAR was collected or is it when it got exported or published. (Screenshort below).

Also if you use the feature info tool and go to one LiDAR dot, it shows the GPS _Time. How can I convert, if possible, that time to UTC time? (Screenshot below) Is that an indicator for when the LiDAR was flown?

Thanks for the help!


Answers

  • bmg_mike
    bmg_mike Global Mapper Guru Moderator, Trusted User

    The FLIGHT_DATE metadata attribute should be what date the Lidar was flown, assuming whomever generated the Lidar files actually filled that in correctly. Of course, some data sources might have some process where they end up filling in the file creation date rather than the actual flight time, but there's no way to know that on the Global Mapper end.

    I have added a new todo item GM-15075 for adding an option to convert the GPS_TIME value to a human readable time.

    Thanks,

    Mike

    Global Mapper Guru

  • Thanks Mike for the feedback. Is there another accurate way that I missed on how to check the exact date when the LiDAR was flown?

  • bmg_mike
    bmg_mike Global Mapper Guru Moderator, Trusted User

    You haven't missed anything. The FLIGHT_DATE is the best barring conversion of the raw GPS_TIME to something human readable.