I think Phil has the right answer for the MM CE with Fast Survey using an autonomous position. I did a long localization on a known point (999 readings took a little more than 15 minutes). I then "staked" to the point for about an hour.
It didn't deviate more than a few tenths N/S and E/w, and just over a foot max in the vertical. I realize that a different day and a different constellation might have different results, and may require a new localization. We may be able to get sub foot accuracy for several hours this way.
Changing the false e/n didn't have any affect on the unit accuracy. A person could probably create a new projection with the itrf/nad83 offsets, but it appears to ignore edits made to the pre-defined state plane systems.
It's looking promising. More testes and guesses to follow. Supposed to rain here tomorrow.
terry
The single point autonomous localization with a mapping grade receiver...now that's a novel idear.
;)
Try it again, same point different day and see what happens. Then, just for grins, emulate the process of a multi point localization around the perimeter of your project area on known control points and solve the localization that way for a scale and rotation....as if running RTK and see what happens.
It might be a whole different ball game since you are using the Mobile Mapper CE and I've been using the Mobile Mapper Pro.
Dangerous Dave
Dave,
Was that your idear? I gave Phil credit based on a post below. Have I commited the unpardonable journalism sin of phlagarism (er, whatever it's called, attributing a body's work to another party)?
I'm just as tickled as a pig with a new bucket of slop. I may be able to do something productice with the MM CE (other than learn new cuss words). I've even ordered an extra battery.
terry
It was my intention to give Dave credit for the whole concept of localization with a mapping grade system. Did I not make that clear enough?
I really do pick the brains of all of you who make any kind of sense to me. Sometimes Dave is more or less dangerous than other times.
I urge caution with making a multi-point localization. Randy's Rules for RTK will be a big deal. Use the test for reasonableness regarding rotation and scale factor. A decimeter here and a half meter there and pretty soon you are talking about a kilometer.
Phil, you did give Dave the credit. I must've missed the thread when ya'll were whoppin on that hoss.
Different day, different time, differnt constellation, yesterday's localization.
9:18 a.m. autonouous position
9:21, DGPS fix
9:28, S 0.35', W 1.85', Cut 5.33'
9:40, S 0.99', W 1.55', Cut 7.89'
9:55, S 0.80', W 1.15', Cut 7.50'
shut 'er down, had to go.
I'm thinking one should do a one point localization on a known point about twice a day if it's practical, might see sub foot accuracy. I will try some more experimenting as time permits.
Huh? I get credit for being "less dangerous at times?"
Mo' dangerous is where its at!
This is a topic I don't care to discuss in this forum.
Dangerous Dave
Modified By Dave Huff on 4/21/2006 at 6:19 PM