Certainly modern mapping, being digital, is more accessible and easier to use. But, is it "better"?
For a map sheet in the City of Pittsburgh, I retrieved a 1926 planetable map, a 1956 update to that, a 1984 map, and a 2009 map. To me the older planetable maps are the best looking, and the 1984 map seems to pretty good as well (done by aerial methods). I note that the 2009 map has contours going through buildings, whereas the other maps appear to be more correct, with contours going to the edges of buildings. Obviously the 2009 map was computer generated with little editing. All were done at 1:2400 (1"=200'). I converted them all to jpegs, so they are a bit large.
An interesting note is that the 1984 mapping was the first use of GPS for a city wide mapping survey. There is also a link to the same map sheet in the control series, which shows traverse monuments.
John Hamilton, post: 385682, member: 640 wrote: Certainly modern mapping, being digital, is more accessible and easier to use. But, is it "better"?
For a map sheet in the City of Pittsburgh, I retrieved a 1926 planetable map, a 1956 update to that, a 1984 map, and a 2009 map. To me the older planetable maps are the best looking, and the 1984 map seems to pretty good as well (done by aerial methods). I note that the 2009 map has contours going through buildings, whereas the other maps appear to be more correct, with contours going to the edges of buildings. Obviously the 2009 map was computer generated with little editing. All were done at 1:2400 (1"=200'). I converted them all to jpegs, so they are a bit large.
An interesting note is that the 1984 mapping was the first use of GPS for a city wide mapping survey. There is also a link to the same map sheet in the control series, which shows traverse monuments.
http://www.terrasurv.com/sheet 27 topo 1926.jpg
http://www.terrasurv.com/sheet 27 topo 1956.jpg
http://www.terrasurv.com/sheet 27 topo 1984.jpg
http://www.terrasurv.com/sheet 27 topo 2009.jpg
http://www.terrasurv.com/sheet 27 control.jpg
John,
Where did you find these?
I've been looking for the control sheets for years.
Any chance you've found scans of the Index cards?
Bob: I have scans (and a hard copy set) of all of the control sheets. I would like to put them online, but I need to go through and name them correctly. At this point they are just individual pdf files with sequential names (HPSC0197 to HPSC0354). I also have a digital set of recovery notes and sketches for many of the triangulation stations. The index cards have NOT been scanned. I brought it up last time I was down at public works getting copies of index cards, but they said they don't have the money/equipment/manpower to do that. I think someone with the right type of scanner could do it pretty easily. I think that is the only way to guarantee that they don't slowly disappear. I was told some are already missing.
You can email me or call me if you need any of this stuff.
412.341.5620
Thanks for the post.
It is interesting to see the city planning commission and engineering department performing this mapping for the city in 1926 and then revised in 1956. These editions are my preference. The 1984 looks good too.
The 2009, I agree, looks bad.
I've seen some good digital mapping done by a experienced and careful microstation tech But I have seen a lot of substandard mapping too from the inexperienced or careless users.
Also interesting that the mindsets of these previous early mapping projects probably directly relates to the current revival and renaissance of Pittsburgh
There is an excellent report about the 1920's surveys....
http://www.terrasurv.com/City%20of%20Pittsburgh%20Geodetic%20Survey.pdf
I have recovered a number of triangulation stations, and tied in some when I needed to do a local transformation for a survey in an area. Always fits real well.
John Hamilton, post: 385687, member: 640 wrote: Bob: I have scans (and a hard copy set) of all of the control sheets. I would like to put them online, but I need to go through and name them correctly. At this point they are just individual pdf files with sequential names (HPSC0197 to HPSC0354). I also have a digital set of recovery notes and sketches for many of the triangulation stations. The index cards have NOT been scanned. I brought it up last time I was down at public works getting copies of index cards, but they said they don't have the money/equipment/manpower to do that. I think someone with the right type of scanner could do it pretty easily. I think that is the only way to guarantee that they don't slowly disappear. I was told some are already missing.
You can email me or call me if you need any of this stuff.
412.341.5620
Thanks.
I may take you up on that the next time we're doing a city job.
