Traditional aerial photography is taken with the camera pointing straight down towards the ground (nadir imagery as we call it). Aerial photography can also be taken pointing at an angles between 0 degrees (straight down) and 90 degrees (to the horizon), normally at 40 degrees. This is called oblique aerial photography.
Oblique photography has a number of benefits;
- You can see the sides of buildings or features from multiple angles
- It gives a more intuitive view of the area being photographed
- It can be calibrated to allow height measurements
This type of imagery gives the user greater insight into the scene to allow even better understanding and decision-making capabilities.
The Oblique Module is a paid optional extra to XMAP and Parish Online. Oblique imagery can be commissioned by a range of aerial survey data providers, including Geoxphere, and the data can be displayed and shared within an organisation through XMAP and Parish Online.
Opening the Oblique Module
- Zoom to the location you want to view
- Click the tool named "Oblique". It may also be named differently depending on the supplier of the imagery, for example "MetroVista Oblique".
There are two ways oblique imagery is displayed;
- Side-by-side against the map
- Below the map
- When hovering over the map, you'll also see a yellow marker. This gives you a guide to the area your cursor is over. This helps orient yourself.
- When moving the map, the oblique images will move to centre themselves at the same location as the map. This may mean the oblique image switches to a different view.
- When moving the oblique images, the map will move when the viewer switches to the next oblique image.
- The zoom is independent from the map to the oblique.
Uncouples the syncing between the map and the oblique (but it doesn't always work) (best to be honest!)
Overlays an orthophoto onto the map (if the oblique imagery is supplied with an orthophoto)
Toggles the look-angle of the oblique through North, East, South, West
Toggles the blue footprint (coverage) of each oblique image on the map
Performs a height measurement. Click at the base of an object then click at the top. It will display a line and a measurement label.
Performs a horizontal measurement. Click at the start point then at the end point. It will display a line and a measurement label.
Performs a facade measurement. Click at the base of your object, then the top, then the adjacent top, then the base, then the original point. It will display an area and a measurement label.
Delete all measurements. Note, when moving to another oblique image the measurements will be deleted automatically.
Switches between side-by-side and above-below display modes.
Closes the Oblique module.