Gene Kooper, post: 421160, member: 9850 wrote: Hey, thanks for outing yourself FrancisH! :rofl:
And don't go dissing our Bigfoot!
You have your mythological monster in Loch Ness (for when your worldly travels bring you to England).Otherwise, watch out for Hantu Air when out with your RTK rover in the boat.
Nessy moved to England? And please don't say Scotland is England....
Luke J. Crawford, post: 421410, member: 11382 wrote: Nessy moved to England? And please don't say Scotland is England....
Ssssshhhhh! I've been waiting for Sean from England to finally notice! 😉
Sean Ora, post: 420994, member: 12254 wrote: So I guess the amrican surveyors have these in common:
1. Practice surveying based on their archaic ways
2. When someone from an international community points out their way of doing things and it does not conform with their practice
they ridicule that person without first checking if his method is accepted internationally.
3. When asked to back up their claim they throw insults instead of providing a technical basis for their claims.
4. Getting links from youtube seems to be their practice of providing proofs to their claim
American, ya forgot the E there Mr. ngland.
Gene Kooper, post: 421411, member: 9850 wrote: Ssssshhhhh! I've been waiting for Sean from England to finally notice! 😉
He's not a Brit, he is Portuguese, maybe Italian judging by his temper. No self respecting Englishman would allow himself to be baited into such a spectacle.
rfc, post: 421396, member: 8882 wrote: Would you answer this please:
Why are you so rude, Sir?
It's a coping mechanism, to deflect away from his own insecurity. Sad!
Just because I'm paranoid, doesn't mean they aren't out to get me.
Well that was fun - NOT.
Just caught up on this thread - that's a second entry for my ignore list
well well well, a lot of answers yet none about the links that I was asking to refute my method.
Talk talk talk talk, sad what americans have become.
Sean,
Can I ask why we should we look abroad for our survey methodologies?
Luke J. Crawford, post: 421461, member: 11382 wrote: Sean,
Can I ask why we should we look abroad for our survey methodologies?
What makes you think he's not American?
I'm pretty sure he is - judging my his excellent spelling that is consistently US English.
Sean Ora, post: 421457, member: 12254 wrote: well well well, a lot of answers yet none about the links that I was asking to refute my method.
Talk talk talk talk, sad what americans have become.
The original post in this thread asked two questions.
Supposing I don't have an RTK setup, are static gps observations an acceptable way of establishing vertical control for a design topo project? Any guidelines or recommendations?
The answers quite naturally discussed the use of geoid models to produce elevations from the GPS derived ellipsoidal heights. For whatever reason (trolls gotta troll is an obvious reason) you diverted the discussion to hydrographic surveys and your "most-excellent" RTK method. You then cited a FIG Guideline on how to conduct hydrographic surveys and implied that because it is an international guideline, it must be applied to any other type of GPS survey that produces elevations.
IMO your method is an archaic method for other types of surveys, such as design topo projects (hint, hint the topic of this thread). Your method may be sufficient for bathymetric surveys in limited areas and/or where the SONAR depths have large standard errors. However, it is a very poor choice for the mountainous areas where I work. For example, the geoidal separations (GEOID12B) in Clear Creek County Colorado vary by 0.9 meters in 19 km. Your method would be a disaster. And I will point out again that the first question in the original post concerned static GPS observations. I'm shocked, shocked I say that you didn't include a "most excellent" method of using static GPS observations to conduct bathymetric surveys in your fabulous dinghy. At least that would have been marginally on point.
If you want to discuss appropriate methods of computing elevations for hydrographic surveys, START your own thread, FrancisH/Sean Ora.
Nor is this thread the place to talk about EGM96 and EGM08 either. And, it would be wrong to assume that American surveyors know nothing about those geoidal models. I have used EGM96 for many years with SRTM DEMs to orthorectify satellite imagery in Asia, South America and Africa. More recently, I used EGM08 to create elevations for an 1100 sq. km area in west central Africa. The Canadian imaging software Geomatica has an optional DEM module that creates digital surface models from satellite stereo pairs. My project included 4 stereo pairs of Pleiades tri-stereoscopic imagery (39 GB). The Pleiades imagery has 0.5 meter pixel resolution and Geomatica created a digital surface model at 1-meter horizontal spacing.
I'm shocked, shocked I say that you didn't include a "most excellent" method of using static GPS observations to conduct bathymetric surveys in your fabulous dinghy. At least that would have been marginally on point.
Sir, let me inform your esteem highness that static GPS observation methods cannot be used for bathymetry survey for the simple reason that the rover is placed on an unstable platform on the sea. But if you want to be technical about it, RTK/PPK is just static observation on a movable rover platform.
The Canadian imaging software Geomatica has an optional DEM module that creates digital surface models from satellite stereo pairs.
My dear Sir, again DSM from a stereo pair is next to useless because its elevation point cloud is that of the surface of the trees, buildings, vegetation canopy. You do not get the ground points itself. That DSM then cannot be used to create ortho images because what you need to correctly rectify the stereo pair images are the bare earth ground points or DEM.
An ex-pat with a chip on his shoulder?
squowse, post: 421464, member: 7109 wrote: What makes you think he's not American?
I'm pretty sure he is - judging my his excellent spelling that is consistently US English.
squowse, post: 421464, member: 7109 wrote: What makes you think he's not American?
Center/centre, pile/pyle, curb/kurb, tire/tyre... I usually spell the "British" oddly enough.
@francish same satellites, yes. different processing methodology between static and real time, be advised
We don't do any static work for construction stake-out, but from what little I know about static GPS, isn't it usually quicker to run a level loop?