L1 GPS for Urban Surveys
> I see a lot of crews in my traveling around the city and the rare sight is a crew using GPS instead of a TS.
No, only a dumbass would think that you don't need both GPS and a total station for work around cities.
Kent
> No, only a dumbass would think that you don't need both GPS and a total station for work around cities.
Is it just impossible for you to be civil?
Paul
To answer your question (not the last one)...
Yes, you would have to post process the L1 data in order to proceed. You could certianly accomplish this is a few minutes in the truck (on a laptop), but when all was said and done, it WOULD probably take more then 30 minutes!
Loyal
Pretty fundamental, Paul
> > No, only a dumbass would think that you don't need both GPS and a total station for work around cities.
>
> Is it just impossible for you to be civil?
Uh, what's uncivil about pointing out that anyone who thinks you can do city surveying with just GPS is a dumbass? It's not as if this topic hasn't been discussed almost to exhaustion.
Loyal
> Yes, you would have to post process the L1 data in order to proceed. You could certianly accomplish this is a few minutes in the truck (on a laptop), but when all was said and done, it WOULD probably take more then 30 minutes!
>
> Loyal
Thanks! As usual, Kent dodged that part of my question and started into his insults.
Kent
> Uh, what's uncivil about pointing out that anyone who thinks you can do city surveying with just GPS is a dumbass?
I guess you just dont know the answer to that question Kent..that's pretty sad.
Paul
> Yes, you would have to post process the L1 data in order to proceed. You could certianly accomplish this is a few minutes in the truck (on a laptop), but when all was said and done, it WOULD probably take more then 30 minutes!
Yeah, but in professional-grade work, you have to adjust your conventional survey measurements, too, which you'd want to do at the same time.
Even if all you're doing are lot surveys in onsies and twosies without just some arbitrary bearing basis, as I think Paul has indicated he specializes in, the value of GPS is being able to make ties that are tough conventionally, jumping from street to street over buidlings, fences, and terrain.
Kent
>Yeah, but in professional-grade work, you have to adjust your conventional survey measurements, too, which you'd want to do at the same time.
Adjust what Kent? Take a look at my example of the intersection I will be monumenting. If you notice, two of the ties are tangent to the centerline intersection. I have a monument west and one east that also fix line.
So, since you are such a survey brainiac, please inform me and all the rest of the dumbass survey community how you adjust two straight lines.
Don't buy any GPS eqpt, Paul
> I guess you just dont know the answer to that question Kent..that's pretty sad.
Paul, be sure never to buy GPS equipment, okay? It would never work for you, so just forget about it. I mean never even think about adding it to your toolkit. Just don't do it.
Actually Kent
> Paul, be sure never to buy GPS equipment, okay? It would never work for you, so just forget about it. I mean never even think about adding it to your toolkit. Just don't do it.
I was hoping that you would buy it for me. If you cant afford that, then just send me some of your older gear..either would work for me.
Paul, just forget about ever using GPS
> I was hoping that you would buy it for me.
No, that wouldn't be right. The better plan is for you just not to ever have any GPS equipment. There is no way it would work for you. Don't be fooled by the fact that it works fine for other surveyors. It can't be used in your work. Keep that in mind at all times.
Kent..You are SO right!
>
> No, that wouldn't be right. The better plan is for you just not to ever have any GPS equipment. There is no way it would work for you.
Now that I see the light Kent, I think that I have misused my TS all these years. I have to go now, I am going to kiss my Pentax goodbye and beat it into the ground with a sledge hammer.
Kent..How can I ever thank you for opening up my eyes?
Mighty Mouse
Yeah Paul that's the one: You'll love it.
Mighty Mouse - reply
I think you sent me a PDF of that survey. I remember that for two reasons. One, that the Montana border was like 30 feet of so north of the north line of the survey and, Two, it was one of the finest maps that I have ever seen.
Are we still talking about the same survey?
Kent..You are SO right!
> Now that I see the light Kent, I think that I have misused my TS all these years. I have to go now, I am going to kiss my Pentax goodbye and beat it into the ground with a sledge hammer.
Just don't be tempted to sell the bits and pieces on eBay to raise enough money to buy any GPS gear, okay? It would be the worst thing you could possibly do and would never work at all. There is just no way that GPS works at all in Los Angeles, in fact. So don't even think about it.
Kent..You are SO right!
The insults aside...
GPS is another tool that measures 3D vectors the same as a total station.
It can help you more efficiently build networks.
GPS is not a coordinate measuring tool anymore than a total station.
If you are going to combine GPS and total station then you need network least squares software that can combine all of your measurements. This is something I have not been able to persuade some surveyors of. They hear "least squares" and think "adjustment" but LSA software is really a processing software. It lets you take all of your various types of measurements and combine them together into the best answer for your survey.
LSA lets you be creative so that for example you can do an open traverse and close it with GPS instead of spending another day closing your traverse. You can build an incredibly strong network of measurements in the same time you would spend getting a close traverse (which isn't nearly as strong or reliable as you think).
Many said it to me but it was Donny Stallings who finally managed to install it into my thick head. LSA lets you use your total station and GPS in the way that is most advantageous and efficient for you.
Mighty Mouse - reply
No there is one south of it that's more interesting.
It shows how a couple of crews wirking in different areas can get kind of lost.
Mighty Mouse - reply
OK, different survey. Thone (a poster) sent me the PDF. It was quite an interesting survey. Maybe one of these days he will post it.
Kent..You are SO right!
Although I am young for this site, I am a total dinosaur on using GPS. We talked about getting something like L1 GPS for constraining my work. I have 10+ years of urban-type traverses in places like Burlingame, Palo Alto, Half Moon Bay, Portola Valley, and Redwood City, and have them adjusted together via Starnet, but it seems a hell of a lot more wise to run some GPS control on several critical points and toss them into the adjustment.
How much does a basic L1 system cost, and how long an occupation would one want on a point?
Kent..You are SO right!
Bryan
I suggest that you demo a top of the line trimble or leica GPS unit for a month. You will be amazed that you've worked so long without one.
