A lot of people ask us why the map or satellite image for a certain location is out of date. This page explains why.
Note: You can see and discuss the latest updates at Dave Owen's 3DNZ blog.
3DNewZealand.com uses the Google Maps database for all mapping data and satellite images. This database is used by thousands of websites and television news agencies around the world — you've probably seen it many times without realising it. Organisations that use Google's database are free to add their own material to increase the functionality for their particular audience. In our case we add things like location markers, tours, 3D images, text information and interactive activities.
We use Google because in our opinion they offer the best overall database of maps and satellite images, coupled with the best way to implement the database in our own applications.
It's important to understand that no mapping or satellite image database will never be 100% current. There are too many practical and ethical issues. The best we can ever realistically hope for is a database that is no more than a few weeks old. Unfortunately even that target is a long way in the future.
We get quite a few complaints about satellite photos being out of date. People say things like "Hurry up and get a better satellite photo of my house", as if we could wave a magic wand and make this happen.
Here's a reality check: Not even Google wields that sort of power. To our knowledge there is no-one in New Zealand who can command a satellite to take a photo of your house, and there are very few organisations in the world that could. Even for them it's not possible in the way you might think. Here's how it works:
You can see why it sometimes takes years to acquire a good satellite photo of a particular location. The popular image of a satellite whizzing around up there snapping photos like a tourist is not how it happens.
Not all photos are taken by satellites — some are taken from an airplane. In this case the options are easier and companies like Google can commission planes to take photos. We still need to be realistic though — the world is a big place and not even Google can have planes everywhere all the time. Even if they could, it would be environmentally irresponsible to do so.
Again we must stress that there will not be any completely up-to-date system for acquiring aerial photos any time in the foreseeable future.
Google gets their images from a variety of sources. In some cases they purchase aerial photography from local governments and private companies. Occasionally this results in images changing or even going back to an older version.
No-one can predict the weather the next time a satellite is over your house. You might get a nice photo next week or you could still be waiting next year.
Maps are a different situation altogether but suffer similar practical limitations. Some of Google's maps are out of date and we get as frustrated as everyone else who uses Google Earth.
We can't comment too much on the maps because we don't really understand all the commercial and copyright issues Google has to deal with. Our understanding is that they try their best to get current mapping data from a variety of sources on an ongoing basis. All we can hope for is that enough people keep requesting New Zealand maps to keep it profitable for the various companies to stay up to date.