Well, I think I've finally managed to clean up the errors, taken additional measurements etc. But now, even with tightening up my standard errors for the instrument and centering, I'm getting an error factor for angles that now seems too low:
I thought I'd read that you should adjust your instrument error settings such that the error factor for angles approaches 1.0.
Here's what I'm using currently, in Starnet:
And here's the traverse:
> Well, I think I've finally managed to clean up the errors, taken additional measurements etc. But now, even with tightening up my standard errors for the instrument and centering, I'm getting an error factor for angles that now seems too low:
>
>
> I thought I'd read that you should adjust your instrument error settings such that the error factor for angles approaches 1.0.
No- you should adjust your instrument error settings to realistic approximations of what occurred in the field. [sarcasm]That - in conjunction with everything else- including proper alignment of the planets and absence of dippy idiots should result in the error factors approaching 1.0...[/sarcasm]
your inst. centering errors should be less than 0.01' if your gear was in adjustment.
tgt centering errors will vary depending on what you had- prism pole and bi-pod at your skill level- probably around 0.02...
> your inst. centering errors should be less than 0.01' if your gear was in adjustment.
> tgt centering errors will vary depending on what you had- prism pole and bi-pod at your skill level- probably around 0.02
Yes, that's absolutely right. The values of centering errors are way too large to be realistic. You tested your instrument centering error and found that a standard error of +/-0.001 was pretty much correct. I haven't read a post describing how you tested target centering.
> > your inst. centering errors should be less than 0.01' if your gear was in adjustment.
> > tgt centering errors will vary depending on what you had- prism pole and bi-pod at your skill level- probably around 0.02
>
> Yes, that's absolutely right. The values of centering errors are way too large to be realistic.
OK. I changed the Instrument centering to .01, and the Target centering to .02, and...voila:
I think I'm finally getting somewhere (on the angles at least) Still don't know what's up with the distances. I've got the Instrument manual's spec. in there right now. It's probably too tight.
you need to look at your listing file to see if the distance error is in a few legs or some everywhere...
> OK. I changed the Instrument centering to .01, and the Target centering to .02, and...voila:
>
>
>
> I think I'm finally getting somewhere (on the angles at least) Still don't know what's up with the distances. I've got the Instrument manual's spec. in there right now. It's probably too tight.
Not so fast. If you are centering the instrument over the ground points in the same way that you did in your tests, you should not have a large instrument centering error like +/-0.01 ft.
I would suspect that the real problem is a prism/target on a handheld prism pole. Those centering errors are more difficult to characterize.
Have you run blunder detection with more realistic centering errors to see which stations are highlighted?
>
> Not so fast. If you are centering the instrument over the ground points in the same way that you did in your tests, you should not have a large instrument centering error like +/-0.01 ft.
>
> I would suspect that the real problem is a prism/target on a handheld prism pole. Those centering errors are more difficult to characterize.
>
> Have you run blunder detection with more realistic centering errors to see which stations are highlighted?
I was talking about the Distance factor specifically being too tight, not all the settings.
In any case, regarding blunder detect, you mean this table?:
The largest apparent adjustment is on the 1-2 distance, but I've measured it from both ends; same measurement (239.36). None of them have the asterisk though.
> I would suspect that the real problem is a prism/target on a handheld prism pole. Those centering errors are more difficult to characterize.
>
I can't remember if I used the pole for any of the measurements on this traverse, but if I did, it definitely would have screwed things up given that I just discovered that my prism pole vial was not level...which could have resulted in distance errors as large as +/-.05'
> The largest apparent adjustment is on the 1-2 distance, but I've measured it from both ends; same measurement (239.36). None of them have the asterisk though.
Look at your input data again. You didn't enter 239.36 for both 1-2 and 2-1.
> Look at your input data again. You didn't enter 239.36 for both 1-2 and 2-1.
Absolutely correct, Sir.
Sheesh.
I set the Instrument distance constant back to spec (.009),
Put the Instrument centering error at .005, and left the Target Centering error at .01
[
So here's a question:
With a data collector, can you feed measurements DIRECTLY into Starnet, in the format required "M, From-At-To Distance", etc., without ANY editing or mucking about?
> So here's a question:
> With a data collector, can you feed measurements DIRECTLY into Starnet, in the format required "M, From-At-To Distance", etc., without ANY editing or mucking about?
I do with data collector files in SDR format. You'll still have to do some minor editing (such as adding a ".DELTA OFF" line to be sure that the input is processed as S Dist Z Angle data) and formating just to have the input file look as much like a fieldbook as possible for future reference, but it won't require manual entry of measurement data.
You'd want to verify that Star*Net's conversion routines will handle a particular DC format well. I'm pretty sure that the converters from SDR and RAW formats work well. Other Star*Net users will have more reliable information about formats other than the SDR format.
> So here's a question:
> With a data collector, can you feed measurements DIRECTLY into Starnet, in the format required "M, From-At-To Distance", etc., without ANY editing or mucking about?
Yes. Micro Survey has a product that allows for conversion from various data collector software's raw data files. It uses the "M" code and/or the "SS" code. It can be set to use From-At-To, or At-From-To...I use it all the time with Carlson raw data files. It is pretty slick.
