Anybody out there is welcome to answer this provided they can say it so a poor ol coonass boy can understand....

Why do the data recording intervals on the Rover and Base receiver need to be set the same ??

I've done a coupla "accidental" experiments in the past when Base 1 was set to 2 seconds, Rover at 2 seconds, and Base 2 at 10 seconds. heck I even had one job where both bases were at 10 seconds and the Rover at 2.

In all cases this has happened the bases had occupation times of 3 or more hours.

Most points in K mode with an H loc. under .1 residuals, with a couple that busted but probably due to obstructions.

In my very limited experience and understanding it doesn't and shouldn't matter. Isn't each point initially positioned independent of all others and essentially a LS adjustment made to determine final coordinates ? (Man, I really shortened that up.)

???????????????
Jimbo

Jimbo,

What length of time were you set for on each kinematic observation? Could be, if I know you, you were on them for at least 30-60 seconds. That would give you 3 to 6 epochs (with 10 sec. set on the base unit) common to the base unit, regardless of the 2 or 5 second epoch you may have set on the kinematic receiver.

If this is a test, did I pass?

J.D.

JD,

Not not not a test.

I always set the Rover at 2 secs. I probably "overstayed" my welcome at each point...like maybe 20 second shots but with slowpoke HP48 processing who knows how long I was really there. I'm doing this from memory because it was a while back...last year sometime.

But it's relevant to being able to use a PM2 on 10 seconds as a base and Locus'
(or is that Loci ?)as K-rover's.

Jimbo

Jimbo,

In your scenario of using a PM2 as a base, and Locus (singular) as a kinematic rover, then looks to me like you may as well set the kinematic epochs to 10 seconds as well and reduce the amount of data collected for download. I just don't think anything above the 10 second recording interval of the base would be of any use to the processing. I do see where you're coming from though. May require 30-60 second occupations to get good kinematic results so you could have at least 3-6 common epochs for processing. What do I know about kinematic anyway. I consider you to be my local expert.

J.D.

JD,

I think you are right but my actual experience seems to be a little different than the "book". Of course like you said, I wasn't really there for only 10 seconds.

If i had a base running all the time then I could tie all projects in using a Locus with each crew instead of like now having to send Loci (plural ?) with a crew.

Jimbo

without common recording intervals, you are not processing and using all the data collected.

Using your example, base one is set at two seconds, base two at ten seconds, and rover one at two seconds.

Here is the table:

Base 1 Base 2 Rover 1
10:00:00 10:00:00 10:00:00
10:00:02 10:00:02
10:00:04 10:00:04
10:00:06 10:00:06
10:00:08 10:00:08
10:00:10 10:00:10 10:00:10

As you can see, only one epoch in five is processing back to base 2. Now, if you're staying at each point for long enough to get the necessary solution (usually five common epochs), you should get fixed solutions back to both bases. If you're doing ten second occupations, there will probably be no way the shots back to base2 will fix.

Lew,

Is 5 the minimum no matter what the distance from base to rover ?

I'm thinking (dangerous) that on very short distances, <1 mile, less could work. But I see your point, especially if setting up a base to use "areawide".

Thanks and excellent example....nothing like a "picture" to explain things.

Jimbo

PS. You know you're getting older when ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ you wake up a few hours later !

Jimbo,

The new controller is supposed to handle mobile kinematic (I think that's the name?). You are supposed to be able to shoot a centerline or a curb line or any other kind of line just by walking along and the reciever/controller tags points at every epoch. I bring this up because I am assuming the results of this would be "survey grade" and each point along the line is based on one single epoch. So putting that all together, it would appear that a kinematic solution could be obtained with one epoch. But like Dad said, what do I know? You're the Southeast Gulf Coast Regional kinematic expert.

Shawn

Shawn and JD,

It's starting to get deep so how bout opening the door and letting a little flow out !! Have we once again stumbled across a slightly different technique than intended ???

definition of expert - Anybody that is more than 2 hours from home.

Maybe Brian or Linda or Richard or Mike can tell us if this mobile kinematic is survey grade....

And that is what that wheel Lo-ink sells for a range pole is for....always wondered bout that.


Jimbo

OK Jimbo,

We're calling it "continuous kinematic" (as opposed to "stop-and-go"), and yes, it's survey-grade as long as you maintain lock to >4SV's. I didn't know anyone sold a rangepole with a wheel, but that would make sense.

Regards,
Brian

Brian,

You just made this poor ol coonass happy. Looks like I might be needing to upgrade to one of them new controllers and software, especially if a project I have in mind comes thru.

So in theory if you were operating the base at 10 seconds and the rover at 2 seconds, every 10 seconds you would get a good point ?? And are the ones in between interpolated or thrown away ??


Shawn,

Ya did it again !!!

Jimbo
Modified By James Webb on 8/14/2001 at 3:09 PM

Jimbo,

No interpolated points, ONLY for epochs with common data at base and rover, so yes, every 10".

Have fun,
Brian

and to think.....I used to go fishing 2 or 3 times a week for fun......