A new map is now online featuring complete New Jersey 1980's aerials along with the tri-state area, including Philadelphia, New York City and Long Island.
https://boydsmaps.com/#15.00/40.548115/-75.210790/nhap80/0.00/0.00
These aerials were acquired by the USGS National High Altitude Photography (NHAP) program which was the predecessor to the 1990's National Aerial Photography Program (NAPP). After some searching, I found complete coverage of New York on an obscure USDA site. Could not find any 1980's imagery for Delaware, Connecticut, Massachussets or Rhode Island so those areas are blank on this map. I considered substituting 1990's imagery, but but rejected that idea since it gets too confusing.
PASDA has complete Pennsylvania NHAP coverage (over 2000 plates) but the catch is, they are not georeferenced. So, I dug through a huge number of overlapping plates and ended up with 87 that could provide just enough coverage of Eastern PA to square off the "Jersey S-curve" and provide a straight Western boundary for the map. This turned into a big project - I used the 1990's NAPP aerials as a reference but was surprised by how much things changed over 10 years. In the 80's, the mountains of Pennsylvania were a pretty wild place with few distinctive features standing out. By the 90's, there were a lot of new homes, roads and lakes. But I identified a total of 5 matching points on each photographic plate, one near each corner and another near the center, which took about 20 minutes each. This provides basic georeferencing but the accuracy is poor, in the range of +/- 20 meters probably. I think it would take 20 control points and around one hour for each plate to do a more acceptable job, but that just wasn't gonna happen.
The original plates are pretty cool, just from an historical/artistic point of view. Here's an example of one that has been georeferenced, the blue rectangle is the only portion that was actually used and there's still considerable overlap between plates.
Some of the plates show a row of gauges (or should I say "gages"?
) along the top edge. That's an altimeter on the left, bubble level in the middle and clock on the right, for example.
I suspect that the main issue with georeferencing is the size of these images, which cover a full USGS 7.5 minute 24k quadrangle. The 1990's NAPP aerials only cover one quarter of a quad and were photographed from an altitude 30,000 feet above mean terrain. The 1980's NHAP aerials were shot at 40,000 feet above mean terrain. The additional distance and coverage area could magnify any errors in the imagery. For example, if the camera wasn't pointing straight down, the image would be "keystoned" and even a slight error of less than one degree would be substantial at 40,000 feet.
I should point out, there are no changes at all to the Southern New Jersey portion of this map, so if you're only interested in the Pines there's nothing new here.
Anyway... the new map is now available. Any links to the old 1980's pines aerials will give you an alert and re-direct you to the new map. You will probably have to manually change your favorites if they included the old 1980 aerials. And you will no doubt experience browser cache issues if you have recently used the old map. As usual, clearing your cache should solve this. If you're using a computer, the followiing article may help.
fabricdigital.co.nz
A phone can be more stubborn, as there isn't a way to do this. If you've installed the web app on your home screen, you might need to delete it and re-install if you're having problems, sorry.
https://boydsmaps.com/#15.00/40.548115/-75.210790/nhap80/0.00/0.00
These aerials were acquired by the USGS National High Altitude Photography (NHAP) program which was the predecessor to the 1990's National Aerial Photography Program (NAPP). After some searching, I found complete coverage of New York on an obscure USDA site. Could not find any 1980's imagery for Delaware, Connecticut, Massachussets or Rhode Island so those areas are blank on this map. I considered substituting 1990's imagery, but but rejected that idea since it gets too confusing.
PASDA has complete Pennsylvania NHAP coverage (over 2000 plates) but the catch is, they are not georeferenced. So, I dug through a huge number of overlapping plates and ended up with 87 that could provide just enough coverage of Eastern PA to square off the "Jersey S-curve" and provide a straight Western boundary for the map. This turned into a big project - I used the 1990's NAPP aerials as a reference but was surprised by how much things changed over 10 years. In the 80's, the mountains of Pennsylvania were a pretty wild place with few distinctive features standing out. By the 90's, there were a lot of new homes, roads and lakes. But I identified a total of 5 matching points on each photographic plate, one near each corner and another near the center, which took about 20 minutes each. This provides basic georeferencing but the accuracy is poor, in the range of +/- 20 meters probably. I think it would take 20 control points and around one hour for each plate to do a more acceptable job, but that just wasn't gonna happen.
The original plates are pretty cool, just from an historical/artistic point of view. Here's an example of one that has been georeferenced, the blue rectangle is the only portion that was actually used and there's still considerable overlap between plates.
Some of the plates show a row of gauges (or should I say "gages"?
) along the top edge. That's an altimeter on the left, bubble level in the middle and clock on the right, for example.I suspect that the main issue with georeferencing is the size of these images, which cover a full USGS 7.5 minute 24k quadrangle. The 1990's NAPP aerials only cover one quarter of a quad and were photographed from an altitude 30,000 feet above mean terrain. The 1980's NHAP aerials were shot at 40,000 feet above mean terrain. The additional distance and coverage area could magnify any errors in the imagery. For example, if the camera wasn't pointing straight down, the image would be "keystoned" and even a slight error of less than one degree would be substantial at 40,000 feet.
I should point out, there are no changes at all to the Southern New Jersey portion of this map, so if you're only interested in the Pines there's nothing new here.
Anyway... the new map is now available. Any links to the old 1980's pines aerials will give you an alert and re-direct you to the new map. You will probably have to manually change your favorites if they included the old 1980 aerials. And you will no doubt experience browser cache issues if you have recently used the old map. As usual, clearing your cache should solve this. If you're using a computer, the followiing article may help.
How to hard refresh your browser Chrome, Firefox, Safari
Hard refreshing your browser clears your cache and forces your browser to download a new copy of the website. This is extremely helpful when you developing a website and need to see new changes.
fabricdigital.co.nz
A phone can be more stubborn, as there isn't a way to do this. If you've installed the web app on your home screen, you might need to delete it and re-install if you're having problems, sorry.
