HI…first post
I am setting up a shooting range on my ranch. The targets will be steel gongs (plates) at various ranges from an initial shooting point. The ranges will be from 50 yards - at various increments - to about 2500 yards. I need to know the exact position of each target so i can find them on a map.
More importantly I need to (as accurately as possible) calculate the line of site distance between different targets.
It seems that if I get the RTK Surveyor and the GNSS Multi-Band L1/L2 Surveying Antenna (TNC) - TOP106 then I could take each targets position and use some kind of software that would calculate the line of sight distance. Am I thinking correctly. What accuracy will I generally be getting ?
The next step - once I know the distances as accurate as possible is i want to use some various laser rangefinders to measure those known distances to determine the rangefinders accuracy.
There is little to no cellular service in the area - although if I go up to the top of a nearby hill about 100 yards away I can get some reception. Does this help in setting anything up.
Not knowing what I am talking about can anyone give me some suggestions as to what I would need ?
Thanks
I think regular GPS might work; it’s accurate to ~1-2 meters. I have a 17 year old Garmin that does averaging, all you need to do is let the GPS sit for 15 minutes and as it ‘wanders’ around it calculates an average position. I’ve found that to be really accurate, probably to less than a foot. The longer it sits, the more accurate the fix becomes.
Using an RTK set-up will result in even higher potential accuracy, up to 2.5cm when using a base station. You need a clear view of the sky for these, not necessarily cellular signal (these use satellites)…so if you need them to be SUPER accurate/precise, RTK might be the way to go…if you can sacrifice some accuracy for lower cost, GPS can probably get pretty close to what you want.
As far as laser rangefinders go: almost all that I’ve seen max out ~40m; 2500 yards is another beast entirely
You don’t really need RTK for something like this, a regular consumer grade hand held GPS receiver would do the trick. Look for one that has the ability to record waypoints and has a “[waypoint averaging” feature. (Most of the Garmin GPS’s I’ve seen have that.) Using RTK is just going to be a lot more complex and expensive than a consumer GPS, plus you have a handheld GPS for other uses later if you need it.
Place the GPS at the location you want to mark, tell it to record a waypoint and let it sit for about 10 minutes and you should get a waypoint that’s accurate to less than a foot or better. Then use the mapping software that’s available for your GPS to map all the waypoint locations.
Don’t know much about laser rangefinders but golfers use those to find the distance to a hole. You might check a pro shop to see if they have something that would work for you.](Waypoint Averaging Information for Outdoor Handhelds | Garmin Customer Support)
For best accuracy you need to average GPS signals for many hours, because the position errors are strongly correlated to satellite visibility and motion. That is true for determining the RTK base station location as well, when you are using the internal averaging option.
For example, this plot shows how a GPS location can wander about 20 meters, over a period of about 12 minutes. The GPS unit had a clear, unobstructed view of the sky. The variations are clearly not randomly distributed.
