TS Direction Accuracy - Chapter 3

rfc · 2014-09-14T19:56:00Z

Kent said near the end of Chapter Two:"There is a workaround for it, though. If you add four, very sharp marks at minimum distances from the instrument (in other words, the targets of the test range consist of four targets about 8 ft. away at nominally 0, 90, 180, and 270 from the instrument and five more distant ones as previously described) and- take directions to them in the round of directions in each set, and- measure approximate distances to all points (+/-0.5 ft. is perfect),you can enter the directions in Star*Net to solve the standard error of a direction to the more distant targets allowing for the small differences in centering. In this procedure, if you are actually computing the centering errors for each setup, the more distant targets could be as close as 20 ft. as long as they were perfectly stable between sets. While one is at that, it would be easy enough to add extra setups with directions to the close targets to actually determine the standard error of instrument centering at the same time. Ten setups with directions to the close targets should be plenty.The solution via Star*Net is the value of the standard error of a direction that gives a standard error of unit weight in the residuals and can be easily arrived at by trial and error."I'm preparing this next test.Here are my targets:I started the test with another clunker of a TS...the display was screwed up so I had to abandon it, but I found that these targets would be super accurate at a shorter distance than 150'. It took me 45 minutes just to lay out the "pentagon" at the local elementary school. This would be way easier at 20' or even 50'.The center mark I'm setting up on has a very tiny hole in the paper, and it's backed with black electrical tape, making a center mark about .020" in diameter, making the centering errors less than about .002' if I take my time (which I did/will). You can't see it in the photo. The dot in the optical plummet exactly covers the hole when centered.Then, I wasn't sure that the 5 distant targets should have been shot WITHOUT re-zeroing the instrument, after sighting the 4 close targets. Does it matter, if I'm putting these into Starnet? If I zeroed in between shooting the 4 and shooting the 5, wouldn't Starnet just rotate the two sets?Also, I still am not sure if there's any advantage to shooting with both faces, and if so, once you flip and turn the scope, do you re-zero then?Bottom line, with this kind of digital TS, does zeroing the unit do absolutely anything at all, except internal math...i.e. nothing with the reading of the plates?

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rfc

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"Ready to run Star*net file"

> It may be that the limit on the demo version of Star*Net is the number of points, not observations. I don't know. If so, you should be able to adjust all of your observations in demo mode, but the offer stands to run the adjustment if you post a Star*Net file substantially ready to run.

There's not much out there I can find on Starnet file types (at least not in the manual).
But it looks like I can cut and paste data directly into the data area from Excel. I'm already entering the data into Excel in order to do some of the math (mean FL and FR, subtract 180, etc.).
If I format all the lines in an excel/word doc, would that constitute "ready to run"?

Posted : September 28, 2014 4:19 pm

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TS Direction Accuracy - Chapter 3

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