Monday, January 30, 2023

Map Skills in the Hood

Last year, I realized I could brush up my map and compass skills by printing out a local topo map and using it to explore my neighborhood. I recently gave this a try and was richly rewarded.

Here was the first stop on my little adventure. One of the side streets near our home dead ends at a fence. It's hard to see, but on the other side of that fence is the Army Navy Golf Course with the clubhouse in the distance. I wondered if I could plot the location of this building on my map using my current location and terrain clues.

I grabbed my current location from the UTM/MGRS widget on my Garmin vĂ­voactive 4 watch.* Alternatively, I could have used the GPS Test app to learn my UTM coordinates from my phone.

I plotted these coordinates using the map's grid lines and a Map Tools Mini Corner Ruler. I noted the location as 'C'.

A quick glance at the compass told me that the clubhouse was due South from my position. Looking at the contour lines, I plotted point '1' in purple as my guess of the building's location.

Once at home, I used Google Maps to determine the latitude and longitude of the clubhouse. I plugged these values into Backcountry Navigator to reveal the equivalent UTM values. Finally, I recorded these coordinates in purple on my map by again using the Mini Corner Ruler.

Success! As you can see below, my guess of the building's location agrees with the actual value. I repeated this process a handful of times: plotting known values in black, guesses in purple and actual values in red.

Most of my guesses were fairly accurate. I ran into issues with guess '2' because I incorrectly converted miles to kilometers. Curse you imperial units!

*Alas, I didn't grab a photo of the actual coordinates at the fence-line. The coordinates in the picture are from another part of my stroll, but the concept is still the same.

No comments:

Post a Comment