Global Mapper v25.0

Measure Tool question

Thereh
Thereh Global Mapper User
edited September 2010 in Technical Support
Hi, im new to global mapper and would like to ask about measuring tool. After rectifying an image of a world map, when i measure the North-South distance it appears to be correct at 20k kms. But, when i measure the East-West direction, after some point the distance calculated by measure tool is fuzzy, and the measuring line itself stop extending beyond that point and instead appear from the opposite side. In fact when i measure a point from extreme West to extreme East, the distance is just few hundred kms. Why is that and how can i accurately calculate east-west direction? I have tried for gnomonic, equirectangular, and mercator projection but the same problem persist.
Btw, im using v11.02.

thx.

Comments

  • global_mapper
    global_mapper Administrator
    edited September 2010
    What is happening is that the measurement is taking the shortest distance between the two points, which might be crossing the anti-meridian (180W/180E) rather than continuing straight east across the world. For example it's must shorter to go from Hawaii to Japan going west from Hawaii then it would be to go east.

    If you really require the West to East distance, simply left click once or twice along the path to force it through a point, then you should get what you are after.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com