Accuracy of Montana 700 Topo graphics

I have been trying to use the Topgraphy feature in the Montana 700 here in Abu Dhabi in my jeep. But I am finding the elevation information incorrect.

The Garmin shows me Elevation lines at 429 in this area of dunes and sand. When I put a pin on this line and press for more detailed information, it shows me anything but 429 ft. I have tested the feature in other nearby deserts and with a 625 ft elevation line. I met with the same problem.

I also have the documented measure of the elevation of a waypoint....it is 382 ft. Yet the Garmin 700 Montana shows this point to be at 499ft This is a 100ft or good a 10 storey building type of difference in the layout of the land. This can be tragic in a car.

Can anyone please add to this? Are you encountering the same level of inaccuracy with the Garmin 700 Montana topo graphics.

Sikander

Top Replies

CowboySlim over 4 years ago +1

I determined the elevation, 0 ft. AMSL, of my house with this source: elevation.maplogs.com/.../huntington_beach_ca_usa.50350.html

WRT using a GPS to determing elevations at other locations, I will answer…

All Replies

0 atlas_cached over 4 years ago

Which maps (and versions) are actually loaded on the device?

What are your Altimeter settings?

Can you please share the coordinates for a test location (the 382 ft. location would be a good test).

0 3383379 over 4 years ago in reply to atlas_cached

location is N23 22.037 e53 38.104

0 3383379 over 4 years ago in reply to atlas_cached

Elevation shown is 500ft

0 3383379 over 4 years ago in reply to atlas_cached

CN Middle East & N.Africa NT 2021.10

0 3383379 over 4 years ago in reply to atlas_cached

TopoActive PS MiddleEAast 2020.10

0 atlas_cached over 4 years ago in reply to 3383379

NASA's SRTM3 v3 dataset returns an elevation value of 126 meters (415 feet) for the coordinates you provided (N23 22.037, E53 38.104).

You have not yet indicated what your Altimeter settings are on your device, or if you have ever calibrated the Altimeter on your device, which you may need to do.

Also, where are you getting the Elevation value from on your GPSr? From the Satellite page? Trip Computer Data Field? Which Data Field? 'Elevation' or 'GPS Elevation'?

0 3383379 over 4 years ago in reply to atlas_cached

My Altimeter settings are:

Auto Calibration: Continuous

Plot type are: Elevation/Distance

And no I have not calibrated the Altimeter. Hoe do i do this.

The reading is from the trip Computer Data Fields

0 3383379 over 4 years ago in reply to 3383379

I am curious that if you can access this data "NASA's SRTM3 v3 dataset returns an elevation value of 126 meters (415 feet) for the coordinates you provided (N23 22.037, E53 38.104)." Why is it that the Garmin doers not calibrate itself from this data?

0 3383379 over 4 years ago in reply to 3383379

Do you know the elevation of N 24 29.7803 e054 24.4321?

I can use this to calibrate

0 atlas_cached over 4 years ago in reply to 3383379

Those coordinates are at sea level.