In the past, I presented a lot of maps produced in ARCGIS. One of the strange observations was when a map was produced of altitude in Brooklyn, a strange line, 90 degrees to the horizontal appears from around the 62nd Street - New Utrecht Avenue station (D and N Trains) and stretches south to Coney Island. Since altitude maps or data may be based on aerial observation, perhaps a seam in the photos cause such an image. My source for altitude in Brooklyn in my previous maps was not ARCGIS. Nevertheless, today I added an ARCGIS online basemap and behold, the same line appears. In the past, I used Google Maps to pass over the area and I did not detect any sort of construction or ridge that would generate such an effect from a street level view. What do you think it is? See my map above and look for "What is this?" in red. You can see the vertical shadow. Is this a map in code, an error caused by splicing the photos together, or something that exists? Sorry for spelling errors in the map title.
