Topo Zone


Deaconess-Nashoba Hospital, USGS Ayer (MA) Topo
TopoZone Pro: View Aerial Photos, Download Unlimited Topos UTM 19 288720E 4716863N (NAD27)

I came across this site when doing a search for a nearby hospital.

Are the numbers the numbers you need to create a POI?

Some of the content is free.

Originator of Keeping Your Windmill Alive. Live in MA & have a cooking website. 6 yr. member.

Different format

Topozone uses UTM format by default. On the left side of the browser window, in the drop-down box under "Coordinate Format" select dd.ddd and for the datum select the NAD83/WGS84 - and for the location you note, the stuff at the top of the page above the map will change to 42.5773°N, 71.5739°W (NAD83/WGS84) - those are the coordinates needed to make a POI.

Topozone can be useful for places that have geographic place names, but there's no address to geocode to. It's a neat tool.

*Keith* MacBook Pro *wifi iPad(2012) w/BadElf GPS & iPhone6 + Navigon*

Sorta, but not really

You can use them, but it wouldn't be fun for most people on this website. It's the UTM system, which is for topo maps. UTM 19 is the 19th map in the series (#'s 10-19 cover the U.S., west to east).

In theory there's a way to translate UTM into the more common GPS system (WGS84). But,my GPS, which is modern and current, doesn't have the UTM system in place, so god help you if you want to try and figure it out thru some other automated mechanism.

(There's a ton of different reference systems, like UTM and WGS, or NAD27, or NAD84, that reflect the difficulty of trying to translate 3D reality into a 2D map. There's all kinds of ways to do so (you've seen polar maps I'm sure, where everything starts at the arctic circle, which doesn't have a square on it) vs. street maps which are nice and square in their grids. How do you get a square grid out of a 3D sphere? Good luck! (that's the distortion maps create).

There's also different representations as to how the equator bulges out a certain amount. More modern mapping of the earth, with greater accuracy as to its depiction, has created all these newer GPS representational systems. UTM, I believe, is fairly old, but for whatever reason, it's stuck around in the topo world a long time).

So, you can use the UTM system for yourself, if you want to hike around Ayer. But, I wouldn't want to make POI's out of it, if I were you.


P.S. Jill does all the talking, and I always listen -except when I don't like what she says, and then I just ignore her. She's yet to argue back. That's why I keep her.

Nuvi 350, GPS Map 76CX

Thanks for clearing it up, sorta. lol

Thanks for the info. Sounds like TopoZone isn't a good resource to use for POI creation.

That's okay,othe POI Factory Members have given us several sites.
Thought I found something we could use. Oh well, ya win some ya lose some. smile

P.S. When "Jack" disagrees, I just turn the volume down. Wouldn't that be great in real life if we could do that for backseat drivers?

Originator of Keeping Your Windmill Alive. Live in MA & have a cooking website. 6 yr. member.

Topozone is a good thing

CherylMASS wrote:

Thanks for the info. Sounds like TopoZone isn't a good resource to use for POI creation.

As I said above, TopoZone can find places that don't have well known conventional addresses, but are well known as geographical place names. It was very useful to me in creating my list of National Weather Service radio stations.

*Keith* MacBook Pro *wifi iPad(2012) w/BadElf GPS & iPhone6 + Navigon*


I've noticed that POIs have coordinates in NAD83 format. When I try to use them in my C340 the location found seems to be well over 50-75 miles away from the actual location I'm trying to reach.

I do not find any setup procedure on the C340 to tell it what format the coordinates must be to accurately find the location. It's obvious that the NAD83 format isn't working properly.

Anyone have any ideas?