The Surveyor and Civil 3D
We’ve all used those skills we learned back in kindergarten. Remember the one where we connect the numbered dots to create a picture? Reducing field work is essentially the same thing. With all of the tools and technology we have at our disposal, why do we keep reverting back to our kindergarten days?
The “Field to Finish” workflow is not new, but I am constantly meeting people in the industry who are still not using it. After a very short learning curve, you will find it is a huge timesaver and can increase your profit margin on land surveys.
When I first learned about the Field to Finish workflow, I was an independent surveyor doing small lot topos and some boundary work. My initial thought was “coding points to draw lines is only for the bigger firms and the huge projects. My surveys are so small that it’s easier for me to just draw the lines manually when I get back to the office.” Now that I have graduated from my kindergarten ways and embraced the Field to Finish workflow, my productivity has increased in both the field and the office. I can honestly say that this is the way to do things, even for the small jobs.
Let’s go over the basic workflow and even touch on a few things you may not have tried before.
Linework Code Sets
The Linework Code Set tells the software what to do with the feature. You can customize this to meet your company standards or just use the Sample set right out of the box (Figure 1).
Figure 1
These codes are generally added to the description to your point while in the field but can be added later if needed. One example of this is using the Offset Codes that will be covered a bit later in the article.
Figure Prefix Database
The Figure Prefix Database is basically just a list of all the features you plan on collecting. They can be set up to be used as breaklines for surfaces or just as linework (Figure 2).
Figure 2
The first time you set up your Figure Prefix Database you will find that there is nothing “out of the box.” Don’t worry too much about this because it’s pretty easy to set up all of the features. You can set up all of the figures you need and associate them with the proper layer and style. In Figure 3, you can see one that I set up for a DOT set of survey features.
Figure 3
Collecting the Data
Trimble has a “Measure Codes” feature with their Data Collectors. By setting up your codes before you get into the field, you can greatly reduce time spent surveying. (Not a bad idea if you live in an area of extreme weather conditions.)
Get into the mindset of collecting linear features and not just points. You can collect as many features, at one time, as you can keep straight in your head or in your fieldbook.
I met some surveyors who were told by their supervisor that they could only collect one feature at a time. They were surveying a two-mile stretch of highway. They would start a feature for the edge of pavement on one end of the project and continue taking shots every 100 feet or so for two miles. They would then start a new feature for the centerline and walk back the two miles, and so forth. Needless to say, they ended up walking many miles and taking many days to measure that two-mile stretch of highway.
When collecting multiple figures at once, you need to remember one thing: figures are drawn between points with the same figure code and in ascending order. When collecting points along a road, I like to collect the following cross section.
RDCL – Road Centerline
TBC – Top Back Curb
SW1 – Inside Edge of Sidewalk
SW2 - Outside Edge of Sidewalk
FNC – Fenceline
I follow this set of features to the end of the project, then jump to the other side of the road and collect all but the RDCL on the way back. By doing this, I can measure that same two-mile stretch of highway by walking four to five miles in a zig-zag pattern instead of the 18 miles required by collecting one feature at a time.
Figure 4 shows a sample of some raw survey data coded and ready for import in PNEZD format.
Figure 4
Offset Survey Figures
In some cases, you can use Offset Survey Figures to streamline your work in the field. One way I utilize offsets is when performing as-built surveys on new construction. Instead of taking a shot for all of the breaklines in a curb, I take one cross section of the curb and then just shoot the TBC for the rest of the curbs within the survey. When I get back to the comfort of my office, I add the horizontal and vertical offset codes to my first TBC shot. Figure 5 shows an example of how your first TBC should be coded.
Figure 5
When I import the points and process the linework, I get a survey figure for each offset—all based on my TBC shot.
This method of collecting features shouldn’t be used for older construction or where there are inconsistencies in the geometry. In these cases, you should just collect additional features.
Setting up the Survey Database
In the Survey tab of your Toolspace, right-click on Survey Database and select Working Folder. Navigate to the folder in which you want your database to live. Right-click on Survey Database again and select New Local Survey Database and give it a name. Now your Survey Database is created and needs to be set up for your project. Right-click on your Survey Database and select Edit Survey Database Settings. Set this up for your project (see Figure 6).
Figure 6
One thing to be aware of when setting up your Survey Database for the first time: the Survey Database has a coordinate system associated with it and the default is “No Projection, No Datum and International Survey Foot.” This may work for your project, but if you are intending to use US Survey foot instead of International Survey foot, you may get some unexpected results if you don’t change this setting. A good rule of thumb is to set this up with the same coordinate system in which your project was surveyed.
Importing Survey Data
Now that you have set everything up and have collected your data, it is time to import the Survey Event into your Survey Database.
In your Survey Database, right-click on Import Events and then select Import Survey Data. Select the correct survey database and then Next.
Civil 3D doesn’t like alphanumeric point numbers, so if you have any in your file, either delete them or change them to numeric before importing them. Another thing to remember before importing your points is the format. I export my points from the data collector as a CSV file with PNEZD formatting (Figure 7).
Figure 7
Choosing to put your points in a Survey Network is optional. The Survey Network is just another way you can organize your points. For example, if you had multiple crews collecting data for one day, you could create a survey network for that day and put all of the import events from that day in the same network.
The last step in importing our data is the Import Options. This is where all of the preparatory work comes together (see Figure 8).
Figure 8
Select the Figure Prefix Database and Linework Code Set that you worked on earlier. Make sure you have the boxes checked to process the linework and insert the figures and survey points. When you click Finish, Civil 3D will do all the “Dot to Dot” connecting for you and place your figures on the layers and use the styles you specified in the Figure Prefix Database.
Figure 9
The example shown in Figure 9 consists of two days of fieldwork. I spent about an hour setting up my Figure Prefix Database and processing the linework.
Now that you know the basics, give the Field to Finish workflow a try. You may be surprised at just how much time you can save.
