TL;DR

Bing imagery in Greater Accra Region is very very old but it continues to be used as the primary reference for adding new data into OpenStreetMap. Esri World Imagery however seems more recent in and better aligned thank Bing.

This diary is a comparison of seleted locations in Accra with new developments that can be clearly seen in Esri World Imagery but not in Bing; one of the reasons not to use Bing as primary reference for adding new data into OpenStreetMap in Accra.

Bing imagery also have some interesting imagery offsets and mosaic problems such as the photo below and around this node.

Location on OSM

©Bing aerial imagery (left) and ©Esri World Imagery (right).

I have been mapping landuse areas in Greater Accra Region recently (deleting, adding and replacing multiple overlapping ways by remote mappers, same as that of Kumasi) which revealed these changes. Most of my observations in relation to the recentness of publicly available imagery in OSM concludes Esri World Imagery is the most recent and seems to have a good alignment with existing known data and GPS traces.

Here are two locations in the region that have seen rapid developments recently of which little or no traces can be seen in Bing imagery.

The Bank Square

Location on OSM

©Bing aerial imagery (left) and ©Esri World Imagery (right). Screenshot taken in JOSM

Jamestown Fishing Harbour

Loation on OSM

©Bing aerial imagery (above) and ©Esri World Imagery (below). Screenshot taken in JOSM

Conclusion

• Tracing and aligning features in OpenStreetMap to Bing in Accra at present will be completely useless.
• Compare imagery sources to see which is most recent and use a combination of both instead, in the case of Accra, Esri World Imagery at the moment is most recent and better aligned to existing data.
• Watch out for offsets and imagery mosaic issues

Some other locations that can be compared:

• Junction Mall ==> https://www.openstreetmap.org/#map=17/5.614245/-0.070107
• Flower Interchange ==> https://www.openstreetmap.org/#map=18/5.629172/-0.153586
• Obetsebi Lamptey Interchange ==> https://www.openstreetmap.org/#map=18/5.561502/-0.228774
• Football field ==> https://www.openstreetmap.org/#map=18/5.875589/0.382003
• New roads ==> https://www.openstreetmap.org/#map=19/5.661584/-0.077230