Best bang for the buck for a handheld GPS?

Tango down

Full Member
Dec 2, 2011
604
2
18
Las Vegas, NV
#1
Hello
What would be the best bang for the buck on a handheld GPS. Main goal is to mark the target spot, mark FFP and knowing the distance in between; my LRF only reaches out to around 1.8 K when it is overcast, so need a good plan B.
Thanks
 
Nov 27, 2017
542
685
93
#4
Hi,

Please be sure to understand and realize that GPS and GLONASS have a built in error margin, so depending on what cartridge you are shooting, how far you are shooting and what the target size is; the error of margin of the GPS and GLONASS can be enough to put you off the target...especially the vertical error margin of GPS and GLONASS.

For example, the government commits to broadcasting the GPS signal in space with a global average user range error (URE) of ≤7.8 m (25.6 ft.), with 95% probability. So if you "compound" the error of margin for at your FFP and the error of margin at your target location you could be a ways under or over your target.

Sincerely,
Theis
 

TripleBull

This one goes to 11
Feb 13, 2017
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#6
So if you "compound" the error of margin for at your FFP and the error of margin at your target location you could be a ways under or over your target.
I've only done an LRF vs. GPS comparison twice, both times at ~1 mile. The two varied by ~3 feet. Maybe I got circumstantial "agreement"? With my LRF on a stable tripod, and an 8x10' reflective tarp hung at the shooting position, I get +/- 1 yard deviation at most and often get identical replicate measurements.
 
Likes: Tango down

Tango down

Full Member
Dec 2, 2011
604
2
18
Las Vegas, NV
#7
Hi,

Please be sure to understand and realize that GPS and GLONASS have a built in error margin, so depending on what cartridge you are shooting, how far you are shooting and what the target size is; the error of margin of the GPS and GLONASS can be enough to put you off the target...especially the vertical error margin of GPS and GLONASS.

For example, the government commits to broadcasting the GPS signal in space with a global average user range error (URE) of ≤7.8 m (25.6 ft.), with 95% probability. So if you "compound" the error of margin for at your FFP and the error of margin at your target location you could be a ways under or over your target.

Sincerely,
Theis
Theis
Thanks for bringing up the error of margin; I did not know this.
Here are my info;
Caliber 338 LM, got dope up to 1500 meters, next will be 1600 up to 2 klicks, target size is 24"x24".
I see what you mean, 50 ft would make a difference at that range but it is still probably my best option, short of putting $3000 in a LRF accurate at that range in all weather...or is there other options?
 

Tango down

Full Member
Dec 2, 2011
604
2
18
Las Vegas, NV
#8
I've only done an LRF vs. GPS comparison twice, both times at ~1 mile. The two varied by ~3 feet. Maybe I got circumstantial "agreement"? With my LRF on a stable tripod, and an 8x10' reflective tarp hung at the shooting position, I get +/- 1 yard deviation at most and often get identical replicate measurements.
Lol, 8x10 reflective tarp, good idea, must help for sure. I am more rustic and use bushes and rocks. What handheld GPS are you using?
 
Likes: TripleBull
Apr 26, 2013
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#10
I like the Garmin GPS76 I use it all the time but a short while ago I bought the Garmin GPS 72 which is the same just with a bit lower screen resolution but for $100 it's awesome value for money.
 
May 12, 2006
726
65
28
The Big Country
#11
Hello
What would be the best bang for the buck on a handheld GPS. Main goal is to mark the target spot, mark FFP and knowing the distance in between; my LRF only reaches out to around 1.8 K when it is overcast, so need a good plan B.
Thanks
Not sure you could get a distance to the resolution required for an accurate firing solution. It’s going to show the distance in .1 mile or .1 km distances which equates to 176 yards or 100 meters. Figure it bumps to the next 1/10 at .05 miles or .05 meters so you could be off by as much as 88 yards or 50 meters.

John
 

TripleBull

This one goes to 11
Feb 13, 2017
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#12
Lol, 8x10 reflective tarp, good idea, must help for sure. I am more rustic and use bushes and rocks. What handheld GPS are you using?
Garmin GPSMap 64ST

There are no bushes or rocks where we shoot ELR. Just miles and miles of rolling hills covered with grass and small cactus.

An 8x10' tarp is a blast to fuck with in 30 knot winds, I assure you.

WRT GPS error, see the following:

https://www.gps.gov/systems/gps/performance/accuracy/

Specifically:

"The accuracy commitments do not apply to GPS devices, but rather to the signals transmitted in space. For example, the government commits to broadcasting the GPS signal in space with a global average user range error (URE) of ≤7.8 m (25.6 ft.), with 95% probability. Actual performance exceeds the specification. On May 11, 2016, the global average URE was ≤0.715 m (2.3 ft.), 95% of the time."

So my observation of ~3' differences between GPS and LRF are not that far off the norm, apparently.
 

isofahunter

Sergeant of the Hide
Jun 11, 2010
135
59
28
Hill Country of Texas
#13
I was doing three things at once earlier and did not give right info. Try the Field Area Measure App, it uses Google maps and gps in your phone. I do not have extensive info as I have only used a hand full of times but so far I have found it useful for various distances.
 
Nov 27, 2017
542
685
93
#14
Hi,
Please note the user range error is not the accuracy "error" at the user interface; it is strictly the broadcasting signal error. Within the actual user interface error you will have not only the URE but the actual device margin of error (as the link advises in 16 feet for gps enabled phones) along with anything else that will interfere with the signal.

Sincerely,
Theis
 
Dec 3, 2017
93
9
8
#18
I would look at the garmin foretrex 701. It looks like it can do all the features your looking for and it has applied ballistics in the GPS as well for your firing solutions.
 
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