Hi Ty,

I'm sure you are probably "Promarking" today. Have fun.

I have a bit of advice to pass on to you that was passed on to me regarding GPS.

The Promark2 is a very valuable and reliable GPS unit. However, DO NOT go outside the box and try using them in a manner for which they are not designed to do. Pay attention to what others say about the Promarks that have been using them for a length of time. (I have had mine for over a year)

GPS is not magic. It has flaws and weaknessess (sp) just like anything else. Just because you may have, or will have, found a "new" procedure that "breaks the rules", don't fall into a false sense of security with a "new" procedure that is not tried and tested by other users and Thales Navigation. Believe me when I say that the development team at Thales collectivley probably has forgotten more about GPS than you and I will ever learn in our lifetime. Thales is the best.

Stop and Go with the Promarks is a very powerful tool. But, remember that just because you got good results with it today, using a certain "new" procedure, does not mean that you will obtain good results tomorrow using the same "new" procedure. There are many variables that make GPS observations work. The most important is satellite geometry and availability.

Be careful, Dude. I highly reccomend that you follow ONLY the procedures as set forth in the Thales user manual and the ones listed on their web site.

If I were you, I would print this E-mail message and post it on your office wall and read it everyday.

Keep on keeping on........

John Roberson, Ga. RLS
Augusta, Ga

Modified By John Roberson on 8/28/2004 at 2:10 PM

If I'd stayed "in the box" with my ProMark Xcm units, I'd never known that they(and ANY GPS) could be used for stop & go sessions.

If I'd stayed "in the box", I'd never have known that I can call the ROVER, the base and call the BASE, the rover and that all my S&G kinematic data would be accurate, but "mirrored".

One of these days, while not acting "in the box", I'm going to figure some sort of "use" for this "mirrored" data. Mind you, this is with Promark Xcm, not Promark2.

Presently two bases are being used by a lot of surveyors for multiple vectors.

If ONE of the bases lost lock, the second base and the rover would continue to work.

I wonder if something could be done if ONE of the bases was "faked" into being a rover. ONE BASE(sitting still) and TWO ROVERS(one standing still and one moving). Now you'd have a base, with good lock, "thinking" it's roving, while the ROVER, "thinks" it's standing still, same as the BASE that actually IS standing still.

It's probably nothing, but I'm not a person who just accepts things without a little dreaming/imagining things. AND, who knows, with software and all, maybe there's something to look into.

Ok, John.

It's your stamp.

I don't have to go stand in the middle of the road to know that I will get run over by a truck....... :-)

If I recall correctly, a lot of guys died before the Wright Brothers got it right.



Modified By John Roberson on 8/29/2004 at 12:15 AM

In that respect you're right.

I don't think Ty's going to get himself in trouble. He knows the difference between experimenting and real usage.

If I had more time, I'd be playing more with my little "experiments". As it is, I would never rely on the results of what I "think" I know.

But, I do think these L1 units might be subject to a little "tweaking".

"I don't think Ty's going to get himself in trouble. He knows the difference between experimenting and real usage."


I agree also with what you just said, but it seems to me that Ty just started using the "blue units". It would be a good idea for us (and especially you because Ty trusts you ) to encourage him to use the units as they were designed. After he becomes proficient enough to run the Promark2 in his sleep, that is when he should start "testing" new techniques.

As of yesterday, he did not know that he needs more than a few minutes of CORS data overlap to process his S&G shots.


Thanks

John



Modified By John Roberson on 8/29/2004 at 12:49 AM

I must agree with Mr. Roberson. A basic understanding of the fundamentals of L1 GPS static positioning should be achieved before jumping into the more complex methodology of post-processed kinematic (PPK). Without this fundamental understanding of how static GPS works, and how to assess the results, kinematic is going to be a crap shoot.

Learning how to take advantage of the 'tricks' like on-the-fly initializations with L1 GPS is an example. Sure, it's cool, but it doesn't always work. There are other 'tricks', but they don't always work either, which is why the manufacturer's tend not to advertise them.

Experimentation is always a good thing, but at some point you need to get the equipment into the field to make money and to stamp the results.



Modified By Scott Partridge on 8/29/2004 at 1:18 AM

why are others trying to control my rate and speed of learning? i feel if i want to run before i crawl that is my option to do so. maybey i do things a little backwards, but i still achieve the results i was looking for.
possibly alot faster than others would have by staying in the box, i here of people that have had there units for 2 yrs and have only done what the salesman told them.

this is how i learn the fastest. i have been learning for 29 yrs now, i think i got it down pat.

i do appreciate all the help i have recieved here. i have never been one of those guys. to not share my knowledge or mishaps for everyone to learn from them.

if you dont know...ASK! if i dont know we will figure it out toegether.


ty

People have indeed been using Promarks for two years and staying inside the box.

They are putting their stamps on the results. They use the units as intended and get good solid survey results. The box can be comfortable at times.

I really don't think anyone has tried to slow you down, but perhaps redirect you into using them as intended first and getting your feet wet with stuff that works like the manual says.

Seems you ground truth everything, which is very good and one of Phil's axioms.."Survey something to which you already know the answer"..I remember this quote everytime I get a new piece of equipment. It will serve you well.

And please, do not take it personal my friend. You are getting some who are trying to give you some long distance mentoring..

They are all your friends, otherwise they would not even mention their concern.

tm

We are only trying to help. My sincere apologies to Ty if he thinks that we are trying to slow him down.

As Deral says, it is more of a suggestion to, at least initially, redirect effort to the basics.

I spend a lot of my time training field crews to use a wide range of GPS equipment. An important part of the training is not only the step-by-step procedures for using the tools but fundamental knowledge about 'how' the tools work. For example, I want the crews to know what is happening when the RTK (or PPK) system is 'initializing' and why it is critical to the results. I want them to know what 'loss of lock' really means and how to understand and interpret the various indicators the equipment may give them during a survey. All of this impacts the decisions they make in the field on a daily basis, including when to (and when NOT to) use the different tools in the GPS toolbox.

Consider this example for a moment.....

The USA men's basketball team went to Athens and played as a group of individual players that showed no basic fundementals of how a team should play together. Bottom line is, they thought their skills learned in the NBA would carry them thru the olympics. When the USA went up against seasoned teams that had spent many years together learning basic team fundementals, the USA was lost and looked totally unprepared for the situation they were faced with.

I heard an Argentine (sp) player make the statement that "the worst player on the USA team was better than the best player on the Argentine (sp) team, but the USA played as individuals and the Argentine's played as a team." We all know who won (it wasn't the USA)

So...... what in the world does this have to do with the above thread and surveying as it applies to GPS surveying? If you don't know the answer, then you are in the same boat as the USA basketball team.


There is no Bronze Medal in surveying.


Thanks,

John

PS..... I'm a wise son-of-a-gun when I want to be.
Modified By John Roberson on 8/30/2004 at 12:46 AM

You really seem to be having a problem wth Ty's methodology.

Some people are satisfied with a brand new watch . . . that it keeps time. Some people want to know how the watch works. Ty seems to be more of the Latter.

GPS static, quite seriously has become relatively simple. It's not hard once the fundementals have been learned.

Kinematic is a little more complicated.

Ty is very early in learning and he has issues that he's resolving. The fact that Ty missed the common data thing doesn't bother me as much as if he'd lucked out and got the right data without actually knowing that the data had to be common(a mistake waiting in the shadows).

Fact is, people learn things in different ways. Some people learn from books and apply written directions, some learn by hands-on usage and some people learn by knowing how something works.

I think Ty want's to know a little more than setting the unis up and seeing it work. It seems to me he wants to know how it works and he wants to know how it doesn't work too.

On an old transit, a 90 degree angle right could also be a 270 degree angle left.

There was a discussion a few weeks back about "cut" chains. Ty strikes me as a person who would not only learn "how" to use a "cut" chain, but also as a person who would want to know "why" use a cut chain and what "real" purpose "cut" chains served, rather than only know how to measure with one.

Are you really that concerned that Ty won't learn how to use GPS, or are you more bothered that he's not learning it in a way that's more comfortable with you?

This seems to me to be a cae of "Different strokes for different folks".
Modified By John Francis on 8/30/2004 at 9:13 AM

John F,

I really don't care what anyone on this board does or how they do it. This is an avenue for people to voice an opinion. As I did mine.

You do it your way, Ty does it his and I will continue to do it mine.

Thanks,

John R.

"It's called good old-fashioned horse sense because it is called good old-fashioned horse sense"
Modified By John Roberson on 8/30/2004 at 9:18 AM