Need Old Aerials/Orthos?
This week we added the “Imagery Viewer” which has every aerial/orthophoto that we know of for York County – at least every one we could get our hands on!
The screen capture here shows the extremly long list of aerial/ortho layers as well as some DEM/Hillshade layers. (click on any image to make larger, choose ‘x’ on bottom right to close.)
Layer List for Imagery Viewer (7/2009)
The need for this new website comes from those folks who routinely call and schedule a trip to our office to review older aerial imagery on paper. We scanned these and georeferenced them a few years ago and made them available through our ‘Orthophoto Report’ in the ‘old’ GIS Online. That report provided users with a quick way to view a specific property as it was captured for the last 40 years, but it was not interactive. This site allows a user to make any of our 40 years worth of imagery visible and interact with each to produce the cartographic or professional map output as they need. Most users will probably see any of the layers and find that they can easily make visible the year they want, but will be perplexed by the 1970 & 1980 aerials. So that’s what the section below will describe!
TO ACCESS AND USE 1970 & 1980 AERIALS:
Note: these represent a series of hundreds of scanned and georeferenced tiles. Most imagery we are accustomed to looking at a large countywide mosaic. Unfortunately, with these aerials you have to do a little work to get what you need.
First, perform a search either by using the zoom tool to locate an area of interest or by the various searches we have made available.
Imagery Viewer: 1970 Grid Layer (Toggled Visible) and with Red Label on Map
Second, expand either the 1970 or 1980 folder to observe two layers. You will see ‘photo grid 1970 (or photo grid 1980) as well as 1970 Aerials (or 1980 Aerials). There is an icon next to the ‘aerials’ layer, this indicates it is a ‘group’ layer. If you click on a group layer it expands to show sub-layers below. In our case here you will see hundreds of individual tiles. Which tile to choose you ask??
Third, make the photo grid visible by ensuring there is a check in the box next to it. Don’t worry about the ‘i’ for active or identifiable, just make the layer visible. Observe the grid lines and the label. You will want to take note of and choose the grid that covers your subject area.
Fourth, expand the group layer for the year of aerials you wish to view. Scroll until you find the grid name discovered in the third step, above. Make this aerial tile layer visible.
Image Viewer: Expand the Group Layer
Image Viewer: Making an Image Layer Visible