Friday, December 20, 2013

My Very Short History of LiDAR, GIS, and CAD

In a letter to my son, the young architect.  With a reading assignment from Dad.


Are you architects seeing more about the integration of these three technologies?

LiDAR started more than a decade ago in remote sensing from satellites, first tested from the shuttles for terrain and elevation modeling.  When I was in the Univ. of Maryland GIS program, they were working on calibrating LiDAR for remote sensing of vegetation - different levels of tree canopy to assess forest health.

When I was working GIS in for the city of Philadelphia, the GIS staff started seeing LiDAR in the urban environment.  GIS and LiDAR vendors were partnering with the city to use LiDAR for 3D modeling of the downtown area.  Then they started using portable LiDAR sensors - the size of a wheelbarrow - to survey the subway spaces in Center City.  And the interiors of some buildings.  The focus was public safety and emergency response.

Now we see LiDAR moving into the consumer market - interior design and real estate are the focus of the two articles below.  Made possible because LiDAR sensors are smaller and cheaper.  (Where have we heard that before... )


The architect's reply just in:


We see this happening but don't use it directly.  There is talk of it being used in surveying but not for design. 

We have our own information-imbedded software (Building Information Modeling - BIM) which we use to design with and to communicate material quantities and interfaces.  The first article mentioned intergratig LiDAR and BIM. 

We are seeing companies which market the 3D scanning service for interiors and you can imagine that we could use that for modeling existing conditions, but the issue is that most of the time we need those existing models to contain information - BIM - and to be manually input. 

The 3d rendering company we work with has a portable version of this and they use it to scan interiors because all they need to do their work is geometries and surfaces. 

I can definitely see an integration of this technology with our BIM but we need and additional layer of information. The BIM software that we use is called Revit.  

Sunday, October 20, 2013

"Trusted-Crowd Sourcing" for Rural County Road Assets Survey and Inventory

Working as a GIS volunteer for Caroline County, Maryland, I created the first-ever web map of RACPro road survey data used to inventory signs, crosspipes, and utilities.   Why does this matter?

1.  County road survey can move away from 10-year-old "distance measuring instruments" (DMIs).  DMIs replaced the hand-wheel and use vehicle odometer readings to survey road assets like signs, crosspipes, and utilities.

2.  Instead of one expensive DMI ($900 each), county personnel could now use any mobile device to collect GPS-generated data.

JAMAR distance measuring instruments typically pay for themselves in increased productivity in a matter of days

3.  The survey data is no longer locked into a proprietary data format (.rac).  Our county owns just one copy of the RACPro software that can display this data using 10-year-old MapPoint technology.

4.  The data and map were locked into the RACPro desktop app and were not shareable.  I exported the data to Excel and published it as a web map at ArcGIS Online:

5.  Because of limited resources -- especially personnel equipped with obsolete DMIs and proprietary software -- our county has only surveyed and inventoried a small portion of county roads.  It would now be possible to train other volunteers, such as Service Learning high school students, Eagle Scout candidates, and senior citizens to use their mobile devices to survey and inventory county road 

View Larger Map

Are geolocation using mobile device GPS accurate enough for this type of survey?

I think it is,when used along with the web map app.  Access to the web map with a streets or satellite imagery basemap would allow a survey volunteer with minimum training to place the asset correctly on the map.  And to edit or update the map point as needed.  This kind of interaction with the data and the map are not possible with the DMI and desktop software now in use.

Can volunteers accurately collect this kind of data?  

Maybe better than the current method.  Volunteers can use the mobile device's camera to document their collection.  Quality controllers can use the photo context to verify the record and edit the data in ways that are impossible with the current technology.

Tell me what you think.