California Surveyors Forums

20 minutes into the time slot and they're still trying to get the slides to appear. One might have thought they'd have test-driven the process prior to show time, but maybe they fell victim to "it's always worked before" syndrome.

It reminds me of the time I showed up to give a subsidence monitoring presentation and didn't have the right cable to connect my laptop to the conference room's display.

They're talking about rescheduling the webinar now.

Whoops, they're running now. Yay!

Jim Frame wrote:I showed up to give a subsidence monitoring presentation and didn't have the right cable to connect my laptop to the conference room's display.

That's a sinking feeling isn't it?

Once Kimberly got goin' - fascinating webinar!

An interesting answer regarding who pays for monitoring . . . didn't realize . . . until she mentioned Tidelands - the State is in the Oil Biz too!

Phil - Sonoma

Jim Frame wrote: It reminds me of the time I showed up to give a subsidence monitoring presentation...

Jim, I'm hoping to get the 2018 year scheduled out in the near future. Would you give a "different" presentation on the topic of subsidence next year, March or later? Based on the feedback its a topic that surveyors are interested in and I think it could benefit from multiple varying presentations.

Thanks for considering it, I have a slot with your name on it ... we need appreciated volunteers like Kim and all the others!

Reach the committee here: StateWorkshop@oc-surveyors.org

I don't know that I'd have much to add to the conversation. We pretty much follow NOS NGS-58 and -59 when doing large-scale subsidence monitoring. Constraints are always a big consideration, but there's no one-size-fits-all solution to that. You just have to find stability one way or another to ensure that you're not monitoring with respect to a moving reference.

I think Jim's different approaches on different jobs would be a great asset for people to hear and understand that each job is in fact unique. Similar to a boundary survey.

LA Stevens wrote:I think Jim's different approaches on different jobs would be a great asset for people to hear and understand that each job is in fact unique. Similar to a boundary survey.

I whole-heartedly agree and coincidentally the next free webinar slot would be 1 year from this month April 11/18ish.

What say you Jim? Vox populi (aka the forum) is asking :)

I am familiar with the many subsidence monitoring projects Jim has been involved with over the years and even hired him for the biggest one I have ever worked on. It was a tremendous success and he (and his team) were a huge reason why. I think his experiences, lessons learned, etc. would be of great interest and value to the California surveying community. We have some very serious subsidence problems going on the the lower Central Valley where subsidence networks/arrays need to be established, coupled with other technologies such as InSAR, to monitor and quantify vertical displacements.

He mentioned the challenge of referencing the work to stable control for each iteration, and depending how large the area is you are monitoring (where vertical changes are occurring), that can be an issue. However, there are other factors that must be considered and mitigated so there is as much of an "apples to apples" height comparison as possible. Seasonal patterns, changes in reference frame ellipsoid heights and geoid models, software and equipment variations.

I second the motion to have Mr. Frame make such a presentation, if he is willing to do so.

Scott P. Martin, PLS
California Geodetic Coordinator

Jim Frame wrote:...... You just have to find stability one way or another to ensure that you're not monitoring with respect to a moving reference.

A non-moving reference which is located on a thin crust of fractured rock floating along on a ellipse-ish shaped molten ball of goo, which is spinning and hurtling through space on multiple curvilinear trajectories while being acted on by continually varying gravitational, magnetic and cosmic forces?.

Relatively speaking, that was a much easier task back when the earth was flat and located at the center of the universe.

But linear measurements were relative to the length of the king's foot, so constantly re-calibrating the tools was a b*tch.

Jim, you are being awful quite. :) You have to keep a lower profile if you don't want to be volunteered. :) Jp

I've been quiet for a reason: at the moment I can't imagine finding the time to prepare a suitable presentation. It's not out of the question, but right now I'm just too busy to think about it.

I received additional encouragement "offline" to encourage you. Quite actually some nice compliments directed towards you.

Can I ask you again in 6 months for 6 months out from that?

rmaher wrote:Can I ask you again in 6 months for 6 months out from that?

I don't think I got this job for taking no the first time...