Global Mapper step by step

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greg downing
Posts: 2
Joined: Sun Nov 17, 2019 10:43 pm

Global Mapper step by step

Post by greg downing » Mon Nov 18, 2019 3:32 am

I just bought global mapper to do this and it is is not obvious how this works from the instructions on http://droneharmony.com/help/working-with-terrain.html.

In Global Mapper21:
I used the "online resources" and from terrain data selected the SRTM 1-Arc Second and loaded it.
I zoomed into my area of interest, Selected Export. There is no option labled "Esri Ascii Grid" but I image "Arc ASCII Grid" is the same thing since it also has the ".asc" extension`. I under the Export Bounds tab I would "Draw a box" around my selected area and export.

When I load this data into Drone Harmony it shows my selected area on the wrong part of the planet, it put my Hawaii selection in Botswana and there is no geometric detail, just a pink square.

When going back to Global Mapper I checked the Input coordinate and could see that it was already set to WGS84.

What am I missing here?

greg downing
Posts: 2
Joined: Sun Nov 17, 2019 10:43 pm

Re: Global Mapper step by step

Post by greg downing » Wed Nov 20, 2019 5:56 am

The information that was missing was the projection. By default Global Mapper will set to mercator projection when you import data from the online sources. Mercator will output the data in meters rather than the decimal degrees required. Using Tools-->Configure-->Projection ans switch to "geographic (lat long)" to get the output in decimal degrees.

GLOBAL MAPPER, PLEASE CONFIRM PROJECTION

Martin
Posts: 214
Joined: Wed Mar 28, 2018 4:47 pm

Re: Global Mapper step by step

Post by Martin » Thu Nov 28, 2019 2:18 pm

greg downing wrote:
Wed Nov 20, 2019 5:56 am
The information that was missing was the projection. By default Global Mapper will set to mercator projection when you import data from the online sources. Mercator will output the data in meters rather than the decimal degrees required. Using Tools-->Configure-->Projection ans switch to "geographic (lat long)" to get the output in decimal degrees.

GLOBAL MAPPER, PLEASE CONFIRM PROJECTION
Hi Greg,

Yes that explains the issue. We are currently working on adding terrain features to the DH Cloud (app.droneharmony.com) that will make it easier for you to import and work with terrain data.

Best regards,
Martin

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