What kind of prism do you use for measurement of lets say 1500 ft.? I have Trimble S7 with the MT1000 multi track target which did the job for 1400 ft., but for distance beyond that I have trouble seeing the target. The option is to get a 62 MM prism.
1,500 feet???
I was expecting something more on the order of 25,000 to 50,000 feet!
I guess that I'm showing my age (arrrgh), everything under about 5,000 ft. (sometimes farther) was done to a "single," a triple would get you to about 10,000 (or more), and beyond that I have a "9-set."
To be honest, I don't think that I have "shot" over a couple of hundred feet since I bought my first GPS system back in the late 80s (with the exception of the old Calibration Baseline in Salt Lake that went out to 2,000 meters).
Hell, it's been so long since I fired the AGA 78 up, I'm not sure that it will fire up.
Hmmmm, I'll probably be sorry for that last comment around this group!
Loyal
Leica Circle Prism will return EDM that far no problem.
The Leica mini prism will shoot that far with ATR under the correct conditions.
The GPR1 (circular) has a range of 3,500m while the GMP101 (mini) has a range of 2,000m. Good luck seeing the prism at those distances.
You need to use your heart a little along with the eye.
Your S7 has a maximum range of over 18,000 feet according to the spec sheet. I sure that a round (62mm?) prism will be more than sufficient for 1500 feet. It helps if the day is a cool one and the air is clear. Any sort of fog will kill EDM range.?ÿ
Had to google it to see what a MT1000 looked like - looks like a radio with a crown of peanut prisms and pink LEDs.
As others have said, the prism itself should be able to reliably return a signal.?ÿ If the issue is just being able to see the target, first check to see it there is some manner of target card made to attach to the MT1000.?ÿ If there isn't, fashion one yourself out of plastic and some rubberized material like weather stripping used for cars & boats to hold it snug to the MT1000 body.
But if this is a target that the S7 is electronically linked to in order to do auto tracking, why don't you just rely on the auto lock when you can't physically make out the target?
I don't have the spec in front of me,?ÿ but the S6 will auto track the MT1000 out to 2200-2600 feet. I would think the S7 would be similar or possibly better.?ÿ If you need/want to sight manually a 62mm with target ought to reach out as far as practical most places.?ÿ
Thanks for your responses, but no one said what kind of prism are you using if you shoot 1400 ft.?
Also, I know the ability of my gun, the problem, as John Putnam said, is if you can see the prism.
Evan, the radio signal between the gun and data collector gets disturbed in such distance, you will keep hearing " signal lost".
Single prism at a half mile is as common as can be.?ÿ Shoot a full mile with regularity as well.?ÿ The longest distance we ever shot was roughly a mile and a quarter down a railroad on a cool day.?ÿ Heat waves are the biggest issue.
Once upon a time we set up on one corner of a quarter section, shot the other three corners then split it in half, plus whittled out a tract around a house without moving to another set up.?ÿ Not your common, every day kind of opportunity.
For most work I use the MT-1000 with auto lock out to its 2000+ft limit. Corners and control get at least forward and reverse and sometimes a few sets depending on distance, conditions, and purpose. If I want to sight manually or run a large loop I switch to Seco 6400-10 (62mm nodal) prisms. Because their optical and physical centers are in the same plane, misalignment of the prism doesn't result in angle errors.
Inevitable, old fogey response. Here is what I??d use...
A prism like this should be visible at 1500', heat shimmer notwithstanding.
OUAT, not that long ago, 1500' shots were common. These days distances like that are more often measured with GPS.
This reflector should do the job ???? --
Good article, too--
