Global Mapper v25.0

How to determine SRTM for 3000+ photos?

We are looking for an automated way to determine the altitude above ground (SRTM) for 3014 photo centers that currently have an altitude above sea level. Is there a way Global Mapper can do this?

Answers

  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    Can you provide more details about your data.  You say that you have photo centers that currently have an altitude above sea level.  What format are the photos?  Is the altitude encoded in the image somehow, or is there a separate data set that contains the altitudes?

    Cheers,

    Bob
  • The photo centers are in a shape file, and we are using global mappers srtm as the DEM. We arent using the "actual" tiff images.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Assuming that the altitude is an attribute on each point in the shapefile, you can do the following:
    1. Select all of the point center point features using the Digitizer
    2. Right-click and choose Analysis/Measurment | Apply Elevations from Terrain Layers to Selected Feature(s). 
    3. Each feature will now contain an attribute called ELEVATION that contains the grid elevation at that point.
    4. On the Control Center, select your photo center layer and choose CALC ATTR.  This will open the Attribute Calculator.
    5. Use the Attribute Calculator to subtract ELEVATION from your altitude attribute, putting the result in a new attribute.  This new attribute will contain the altitude above the ground.