Orthophotography as a map background

yes

We use a service called "Nearmap" that allows us to download orthophotography as backgrounds to maps. The engineers around here really like it when we do that. The service updates their aerials twice each year. 37mm pixel size. I also use it to draw in parking lot striping. 

I have used County supplied orthophotography as background for mapping for a transit project. 

yes

Thanks @sergeant-schultz.  Wasn't sure if this was good practice or insurance nightmare.

Yes, used the State's photos often on large boundary surveys with the deed overlaid to create rough search points.

No problem putting an imagery layer into deliverables, as long as we cite the source and make it clear that we did simply referenced it in as a supplement and is for informational purposes only.

@firestix why would it be an insurance nightmare to overlay your survey on a rectified digital ortho as long as both are in the same datum?

I pair up a good many of our winter design surveys with ortho imagery. Some years back when we were not so busy we would spend time shooting in edge of pavement. There are certain permitting requirements that take effect if there is digging within 10' of the edge of a paved road. In winter when that pavement is buried in snow and ice, locating it is time consuming and leaves us vulnerable to traffic, so now I typically pair up the most recent local gov imagery and digitize those aspects. It's a real time and possibly a life saver. I've always been very impressed with how well the ortho imagery syncs with our surveys. The shadow of a utility pole will line up perfectly with our field ties.

@firestix why would it be an insurance nightmare to overlay your survey on a rectified digital ortho as long as both are in the same datum?

Let's just say I have "trust issues" with other people's data.

@firestix 

Its not hard to check three or four points on the ortho against your survey.

Blending an image in as a background can add a whole lot of context information for very little cost. It makes the plan easier to understand and the clients love it.

So, apart from a lack of suitable imagery, why would you not?

I don't use it on every survey, but I find that it adds a bit of eyewash to larger boundaries.  I also use Carlson data collection, and 99.9% of the time have an orthophoto background in the collector.

I use otho imagery a lot as a background to deed plots. Collected by the states I don't worry about its quality. I never utilized it as background on a deliverable much as it could cause a layperson to miss "the important stuff"  I was trying to convey in the actual drawing. 

Another product supplied by some state agencies is LIDAR topo. I have used that on delivereables for certain well and septic plans that don't need grading. I also like it as a backdrop  to larger, farm and wooded boundary surveys. 

Gary

Another product supplied by some state agencies is LIDAR topo. I have used that on delivereables for certain well and septic plans that don't need grading. I also like it as a backdrop  to larger, farm and wooded boundary surveys. 

Here in NC the LiDAR is very good and I use it often for site plans when topo is needed.

@firestix 

Its not hard to check three or four points on the ortho against your survey.

Blending an image in as a background can add a whole lot of context information for very little cost. It makes the plan easier to understand and the clients love it.

So, apart from a lack of suitable imagery, why would you not?

 

@jimcox 
Thanks Jim.  I totally agree with your comment about adding significant context with little cost.  I just wasn't sure about sealing/certifying a map that has imagery data that I did not capture.  I guess I'm just being over cautious.   

For planning and exhibits, I can't remember ever filing a sealed plat or map with an ortho. There are usually a few glitches with any ortho photo that's not collected using high accuracy techniques. The bing maps and Google maps will prove that fairly quickly. 

For planning and exhibits, I can't remember ever filing a sealed plat or map with an ortho. There are usually a few glitches with any ortho photo that's not collected using high accuracy techniques. The bing maps and Google maps will prove that fairly quickly. 

@mightymoe

Fair enough.  However, have you ever sealed a plat with an ortho?

For planning and exhibits, I can't remember ever filing a sealed plat or map with an ortho. There are usually a few glitches with any ortho photo that's not collected using high accuracy techniques. The bing maps and Google maps will prove that fairly quickly. 

@mightymoe

Fair enough.  However, have you ever sealed a plat with an ortho?

 

Yes and no. I've certainly used orthos, digital quad sheets, digital GIS maps on sealed plats for location maps. But for data control or under a boundary or water plan,,,,,,don't think so. 

I rarely use them on surveys, they require clarification, accuracy reference and method; which I don’t usually have. I often send a second pdf with the aerial turned on. I keep the ‘AERIAL’ layer in the dwg file to clients I know well. Duface clients will mess up the aerial, base something on it and blame the surveyor.

@firestix I love the NC lidar topo data. Honestly it is probably more accurate than doing a topo by hand, and I have checked it against hand topo's. I've used it before and it showed objects that I would normally ignore, like septic test pits on a residential lot.

As far as orthimagery, I use it quite a bit, but only for things like checks on what I've shot or picking up stuff like power poles, or the far side of rivers, etc. I have never sent it out as a deliverable though, although I would not have a problem doing so, I would just note where it came from and that I had no responsibility as to it's accuracy. I have done the same thing with the lidar topo data and just note where it came from.

I use NC's orthos and those that I create from my own UAS surveys.  I've used NC's LiDAR to search for and find ancient road or cart beds too.  NC's orthos are PLS certified so there's no problem digitizing from them as long as you clearly differentiate between surveyed areas and digitized areas.

I've sealed a few with an ortho background but it's usually in addition to the standard black and white plat.