I have 3 PM2's (also a Hiper, 3 Novatels and a Sokkia, all L1/L2 units) and use them with L1/L2's for subdivision control including bring elevations from a ways away then having good accurate points with accurate elevations for construction staking. I could do this with RTK, but there is no doubt that I like the redundant accuracy you can prove by multiple ties through a static adjustment. I even throw in a few conventional measurements on occassion, but that is not usual although it really seems to tighten up a network if you do. Typically I will leave them for an hour or so to where the readout usually says I am good for 9 or 12 miles. I often would like to take shots where I could shoot more points with shorter occupation timesand know you need to get "an initialization".

1. How do you know you are initialized. I do RTK all the time and the data collector tells me I am fixed. If the PM2's tell me I haven't seen where.

2. How long or perhaps the better question is how short can you get your occupation times and still feel like your data is as good as a much longer static session.

I don't do a lot of stopngo, but after intialization, a 15-20 second observation with 2 second recording invervals will get you about half (more or less.. I hate to say that) as good as static.

The time for init is something you kinda have to get a feel for. I almost always do known point init, which is really just a static observation, for 15-20 minutes to be on the safe side, maybe longer if the base is a couple or three miles away. If I lose lock and go back to re-init on a known point, I'll give it 2-3 minutes, which might be an overkill.

They will also init on the fly, but you don't really know till you process. Maybe someone who does this a lot will expand and correct my procedures.

terry strickland
add edit: Sometimes I'll do a stop-n-go using 10 second intervals when I'm doing a static survey, and the point I want to occupy is maybe in a rural road, or someplace you wouldn't want to leave a receiver for a long time. In that case, I'll do a known point init (static observation in stopngo mode) on a nail on the side of the road for the required time, and then do a two-three minute observation on the point in the questionable area, and just leave my recording inverval set to 10 seconds same as the rest of the base units. It has worked OK so far, long as there is good sky.
Modified By J. T. Strickland on 11/10/2005 at 8:30 PM

I do S&G with on-the-fly initialization often. It has worked everytime . . . except, maybe not today. I usually don't just turn on the unit & go. I like to at least let the unit burn for 2 minutes before I start doing things, then I try to work for about 30 minutes.

I haven't downloaded today's data yet and my total time between base & rover was about 15 minutes at a 1000' distance.

I'll go ahead and work the data & let you know

missed my previous(conventionally located) points by about 0.05' after adjustment for SPC.

So . . . it seems to work for me.