There is an application for Android phones for field measurements. At least building height and width can be measured with the app.
A quick test showed precision about 5-10%. I'm going to perform more tests.
The app can be used along with the Photo Matching tool of Google Sketchup to provide correct scaling for a building model reconstructed from a photo (see OSM-plugin for Google Sketchup). Just indicate the real length of any linear feature of the model and the model will be scaled accordingly.
The app price is 1 US dollar
The app page at market.android.com: Smart Measure Pro
Quit interesting! But concerning esp. the height of buildings, wouldn't it be mcuh more easier to let people enter the numbers of levels (basic+roof) to describe the model? measuring exact values is quiet difficult and I guess most mappers care about taking OSM not that serious to get the exact height with a digit after the comma
This app can't measure buildings up to 1 cm. If a building is 20 meter high, the app would yield something between 18 and 22 meter (10% precision).
A mapper should know in advance what exactly to measure with this app (e.g. the basic hight, the total height with the roof, etc).
Is there anything comparable for iPhone?
Your idea is quite interesting and useful. I really your idea. thanks for sharing with us.