Coordinate Systems and Drones

And now back to our regularly scheduled program… Have you heard of the drone invasion?

For those hiding under a rock because of the election, or other apocalyptic event,  drones have come to the forefront of data capture for many types of projects. Surveyors are actively digging into the technology to see how it can help them capture existing conditions quickly and at what quality they can capture.3DR and DJI are two companies that are offering drones to the commercial AEC industry.

For full disclosure, Synergis is now a partner with 3DR to provide the technology to our local customers.

The basic idea is the drone would fly a given area, take several pictures and upload that data to a cloud service to create composite imagery or elevation models. In order to accomplish this, All commercial drones have some sort of GPS recorder to stamp each image with coordinates. For clarity, this position stamp is rough in nature given the process described above and is typically within 5′ of the actual location. This is NOT acceptable to most survey firms for anything other than “napkin” sketched projects.

Many services have added the ability to add survey control to the process in order to tighten up the results. There is a best practices method to laying out the control over the capture area. According to 3DR, they can improve the location (x,y) accuracy of their data to within an inch!

In order to accomplish this correction, one bit of information is the need to have an EPSG code to identify the control’s coordinate system.Simply search by state or other information to find the EPSG code. For future reference, here are a few local codes to Pennsylvania and New Jersey.

State	Coordinate System	Unit	EPSG Code
NJ	NAD83	Ft	3424
	NSRS2007	Ft	3616
	NAD83/2011	Ft	6527
PA	NAD83 North	Ft	2271
	NAD83 South	Ft	2272
	NSRS2007 North	Ft	3650
	NSRS2007 South	Ft	3652

In case you need to transform your control coordinates, there is a great tool in that same website to re-project your coordinates from one system to another:

https://epsg.io/transform#s_srs=4326&t_srs=3857

Lastly, if you have Recap 360 Pro, there is a setting to specify the coordinate system. In that setting you use a portion of a typical code (PA83 for instance) and get results which also include the EPSG code.

Until next time…

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Controlling Points in XREFs

This is a post about conversations I have frequently with Surveyors and their office staff. First and foremost, DO NOT EXPLODE any Civil 3D objects! OK, now that I’ve said that… Civil 3D uses point groups and description keys to control how points are displayed, not layers.

Every surveyor just now threw up their hands and said, well… things I cannot repeat here. Let’s take a breath and find out how we can calm the masses while maintaining the Civil 3D model.

Corridor Cul-de-sac troubleshooting

Corridors are quite fun to build, configure and eventually model various surfaces. Everyone has seen the smooth and clean examples.

Sometimes, the corridor object can get out of whack; subassemblies targeting the wrong alignments, daylighting specified to the wrong surface, etc. Maybe you’ve seen this simple error…

Of course intersection can pose their own problems, but what about all of those other corridor examples like bus stops or knuckles or even cul-de-sacs. Recently, I had a chance to help someone with just such an issue. And it looked like this. For some reason, the lane was not respecting the closest target making a hole in the surface.

Let’s see what we can find out….

Civil 3D Style Evolution

I teach a fair amount of classes around the functionality of Civil 3D. One common dilemma I hear students discuss is how to handle styles. Yes, you can put them in a template and have the standard set of styles available. But what happens when I need to present an object differently than the company standard? Agent Smith once said “You hear that Mr. Anderson?… That is the sound of inevitability…”

Yes, style change is inevitable. After the break, I’ll give you my solution which does not end in death…

Disappearing Shortcut Node

This is a quick service announcement for those that don’t use data shortcuts. You or your firm probably do this for one of two reasons. Either you’re standardized on Vault or you put everything in a single file. Either way, you often find that having the data shortcut node visible in Prospector is the most annoying aspect of using Civil 3D.

Well, you are in luck.

Sorting in Sheet Set Manager Model Tab

Alright then… Back from an extended writing hiatus. I’ve not been terribly busy but seemed to need a break from writing.  Today, I am doing some help desk coverage while other members of the team are headed to training at an Autodesk event. This happens every year coinciding with the new releases of the software/applications. So, to get myself warmed up a bit, I took a stroll down to the Autodesk forums and found something called Autodesk Answer Day. The idea is that it is a live Q&A session hosted on a certain forum page. The first answer day was an AutoCAD Answer Day hosted on this board this past Friday on May 7th, 2015. The people responding ranged from community managers and customer service to product designers and analysts.

One of the first topics I noticed was about the sheet set manager. If you have no idea what that is, PLEASE take a minute to educate yourself about the most underused power tool in the AutoCAD platform. Now that you’re familiar, let’s find out what problem is being asked. “Jarsky” wanted to know why the drawings and folders on the model tab did not sort alphabetically. See below for what was happening to him.

Vault Christmas Present

At least it is for me… 

Suppose you have been running Vault Basic or Pro using MS SQL Server Express 2005 or 2008, depending on when you started using document management. One of the primary limitations of Express was the database having a size limitation of 4GB. With Express 2008 R2 and newer, that limitation is expanded to 10GB of data. Seriously? 10GB of metadata, data about the data? That is lots of data.

Now, if you’re using replication, you are forced into a full version of MS SQL Server. For those not using replication, here the two main reasons:

• Manage a central file database across multiple offices, Site ‘A’ and ‘B’ listed below
• Disaster recovery, where Site ‘B’ is simply an off-site server hosting your backup data.

Merry Christmas!