Processing Steps

1. Navigate to your area

You provide the center coordinates or choose it interactively on the global satellite map

To Select interactively, zoom and pan the map. Then double click to create a 2 km by 2 km box centered on the cursor.

You can search a location by entering one of the following:

a Lat,Long (i.e.: 49.28,-123.12)

a DMS (i.e.:49°16'48.0"N 123°07'12.0"W)

An address: 1188 Georgia Street, Vancouver

2. Pick a 2 km by 2 km area

You adjust the 2 km by 2 km survey area interactively on the global satellite map by clicking and dragging the box

Box is 2 km by 2 km

Background satellite photo may not be current

Click the Show available results button to proceed to the pair selection

3. Select your photo pairs

PhotoSat provides you with a list of the WorldView stereo photo pairs that can be used to survey your area

You select the pair of WorldView photos that provides you the best combination of dates and DEM quality

PhotoSat shows you a 10 m resolution image of both images in the stereo pair you choose

If you have selected a cross track stereo pair with images of different dates you need to compare the similarity of the images

Agriculture fields on WorldView photos from different years with different crops. The differences in the fields create noise in the DEM shown below

Noise on the DEM due to the differences in the crops between the cross track stereo photo dates

New developments. The right photo has several features not present in the earlier left photo. These areas will be noisy in the DEM

Noise in the DEM where there are changes between the photos in the different date, cross track stereo pair above

If the images look similar so that they can be used for DEM generation you select this image pair. Otherwise you select another image pair

These photos show similar ground features and will produce a good DEM

Good quality satellite ortho photo and DEM produced from the photos in the cross track stereo pair above

5. Confirm order

You confirm the processing order

Order confirmation page

PhotoSat processes the stereo pair that you have selected for the terrain type that you have specified

6. Download data

24 to 72 hours after the order confirmation PhotoSat sends you an email with download instructions

7. Adjust DEM

If you have ground survey data you adjust the DEM and ortho to fit your ground survey data using ArcGIS or other GIS system

If there are water bodies with DEM noise you flatten these areas of the DEM using ArcGIS

If there are changed areas or featureless areas with DEM noise you level these areas of the DEM using ArcGIS

If you have problems or questions about the processing you contact PhotoSat customer service