Alan Sharp

Image Management in TBC

Blog Post created by Alan Sharp on Jul 29, 2019

I am often asked for more detail on the use of Digital Globe Satellite Imagery in TBC - here are some FAQs and Responses

 

Question 1

Is TBC directly connected to the Digital Globe Image Server when you turn on the background map function?

 

Answer 1

Yes - the Trimble ID login gets you to Connect Services and those services parse your project data and send on the request to the Digital Globe Image Server to retrieve the image set for your project / graphical display area. We do not make a copy of the Digital Globe Satellite Imagery so it is 100% up to date with the Digital Globe Images that are available.

 

Question 2

Is the Digital Globe Imagery the highest resolution imagery that is available from that service provider?

 

Answer 2

Yes - Google Earth is higher resolution in some areas because they supplement the Satellite Imagery with low elevation image data from terrestrial flight imagery. Digital Globe Imagery is all Satellite based imagery.

 

Question 3

What is the accuracy of the Digital Globe Imagery?

 

Answer 3

The Digital Globe Imagery is typically accurate to better than 10m with a >90% confidence in that accuracy. If you see errors greater than that it is likely that it is to do with the Coordinate System and Projection that you are using in your project and the "reprojection" of the Digital Globe Imagery that TBC is doing. Please share example projects where the errors are greater than these stated accuracies for us to take a look at.

 

Question 4

How old is the Digital Globe Imagery?

 

Answer 4

The Digital Globe Imagery is typically updated every 2 years on a rolling coverage basis. When compared with Google Earth imagery it can be both more current or older because the rolling update cycles of Digital Globe and Google are not the same.

 

Question 5

Why do Trimble use Digital Globe Imagery vs Google Earth or other Image Servers?

 

Answer 5

Digital Globe is a) Global and b) cheaper to offer as a service than other providers. While Google is higher quality image data it is significantly more expensive to license than Digital Globe. With the advent of Drone Flying being common for contractors, many projects have high accuracy high resolution data of their own available. We don't see the need to contract with a higher quality image provider because we would have to pass that cost on to you as consumers and  we feel that it is a "fill in" rather than a primary service. You also get the optional Street Maps within this background image function which allows you to map Haul Roads and Site Access Points accurately from existing infrastructure. Trimble Sketchup for example has recently licensed Nearmap for high resolution imagery, however that covers urban areas more than green field areas which may be good for Architects but less so for Civil Contractors. It is also not a Global Coverage service.

  • First you need a Trimble ID - if you don't have one go to this website and follow the steps to Sign Up for a Trimble ID (this will give you a Connect Services Login (uses your email address and password)

 

      Click Here For Link

 

  • Now that you have a Trimble ID - In TBC go to Support - Options - External Servces - Profiles and create a Trimble Connect Service Profile. Enter your rimble ID Username and Password and then tap "Test Settings" and if it passes, Tap "Sign In" and then "Set as Active". This will start the service each time you start TBC.
  • Now you need your Project to have some data in it (a Point or Line is a minimum) and it must also have a coordinate system - that can be a Site Calibration File imported (DC, CAL or CFG file) or can be set using a Coordinate System (Projection and Datum etc.)
  • Now you can tap the Background Map Service Toggle Button at the base of the graphics screen area -  to activate the Map Service.
  • Once active if you want to toggle between Satellite Image and Street Map you can go to Project Explorer and go to the top of the tree and find the Project Name and then look at its properties - In the Background Map section the Type can be "Trimble Mapview" (the Street Map) or Digital Globe Imagery (The Satellite Imagery). Here you can also set the Transparency of the Background Map.

 

Here is the result of showing the imagery behind a TIN Surface Model of the Trimble Building Facility in Colorado, USA.

 

 

Hope that this is useful information

 

Alan

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