2021-08-05 39 -85
| Thu 5 Aug 2021 in 39,-85: 39.9311352, -85.6007168 geohashing.info google osm bing/os kml crox |
How close to do you need to get for success?
Closer.
Location
A lovely bit of farm road right on a property line.
Participants
Expedition
Given the nature of most handheld GPS units, there is an uncertainty to any measurement. Modern consumer GPS receivers can generally expect an accuracy between 3m and 10m, depending on the systems used and the conditions at the time of measurement. My body is wide, but not quite 3 meters wide! What if I had more accuracy? I could have a much better idea of when I have actually reached the coordinates, and know I definitely stood over top of them. Commercial positioning systems can offer much better accuracy through RTK positioning, some even down to sub-centimeter! Wouldn't it be nice if an intrepid adventurer had access to such equipment for use other than serious work?
I set out around 4:30 with coordinates loaded into my Trimble TSC7, running Trimble Access. For this journey I would be using this controller to operate a Trimble R12i with RTK corrections from InCORS. With this system I am able to locate myself anywhere in the state of Indiana that I can get an internet connection, with an accuracy measured in centimeters!
After a quick 40 minute drive down some country roads I approached the fence which marked the property border I knew to be quite close to the point. This turned out to be a very accessible hashpoint, mere feet from the edge of the road. I pulled over and set up my equipment, placing the GPS receiver on its pole (with very pointy tip for accuracy) and connecting the controller to the internet to start receiving high accuracy corrections. I realized around this time that my confidence in my ability to get cell service in this area was unfounded, but using my cellphone as a hotspot and holding it high above my head, I was able to maintain a steady enough connection to get connected and make my way very precisely to the point.
Throughout this whole process, an alarming number of flies that looked an awful lot like bees! I knew they weren't and was mostly unbothered, but I quickly found myself swarmed by dozens of them. Later research tells me that they were hover flies! A cute little critter that just wanted to drink my sweat (so cute). Less cute were the occasional horse fly, over an inch long and making helicopter like noises as they buzzed past me. I feel blessed to have had no contact with those enormous beasts.
Having established my connection and verified my accuracy to be within a tolerable range, I walked the short distance I had left between the point and my vehicle. I recorded my observation of the point for verification, and took the obligatory photo of myself on the point. On the drive home I stopped at a nearby cemetery which also had a geocache hidden in it. Coordinates for geocaches are rarely if ever accurate to the actual location of the cache, and this was no different but I had little difficulty finding it anyway. After a nice walk through the cemetery I returned to my truck and made my way home, having made my first successful expedition in over a decade! This was a bit of a test run and a proof of concept, in the future I hope I will be able to reach more interesting and more challenging hashpoints with even more accuracy. Perhaps I'll break out the total station some time and really pin down that point!
