Surveyor - measure any distance with a single click on your phone

Surveyor is an android application that can help you measure distances with the help of camera and orientation sensors on your phone.

It uses data from orientation sensors and the camera image to determine 3D coordinates of the object you selected and then give you the distance from the object to you or another object.

All you have to do is simply point your phone to the object and then click its video image on the screen at the point where that object touches ground. Detailed guidance have been integrated in the Surveyor application for your convenience.

However the simplicity comes with 2 limitations:

1. It can only measure distances on a flat level surface, sloped or vertical surface won\'t work.
2. The altitude from the level surface to the device should be given to Surveyor as parameter. If a wrong altitude is set, the result will not be accurate.

Surveyor is a freeware, you can download it from Android Market by searching "surveyor" or click on the following link when you are viewing this page on the phone.
Get Surveyor from Android Market

FAQ

Does it support imperial unit system (mile, feet, inch ...)?
Yes it does! Check the next question for how-to.
How can I change unit system?
Press on the result box, a dialog will pop up for you to select the unit system you wanted.
Can I use it to measure the height of a building?
No you can not.
However you can measure the length of its shadow...
Surveyor is designed to measure "distances" on a flat level surface. It won't work for vertical or sloped surface.
Does it work on a slope?
No it does not.
How can I remove markers and start over?
Shake your phone, or press "menu" button then select "Clear markers".
Why is the result inaccurate?
The accuracy of Surveyor depends on the accuracy of the parameters you set and the values returned by the sensors of your device.
To acquire a good result, you need to make sure that you have the altitude parameter correctly set and the sensors calibrated.
Check following questions for how to set altitude and calibrate sensors.
What is the correct value for altitude parameter?
The altitude is the height from the level surface where objects being measured are located, to the phone you are holding.
If you are standing, and objects you want to measure are on the ground, the value should be the height from the hand that holds the phone to your feet.
If you want to measure objects on a table, the value should be the altitude from the table to the phone.
What is the parameter FOV for?
FOV defines how wide your phone camera can see. You don't need to change it unless you are sure that the default value is not suitable for your device.
How can I tell if the FOV is correct or not?
  • Point your phone to an object until you see it in the center of the screen. Click on it to place a marker.
  • Slowly turn the phone left or right until the object reaches the border of the screen. While you do so, observe the movement of the marker.
    • a. If the marker stays on the object, the FOV is correct.
    • b. If the marker moves out of the screen faster than the object, the FOV is too small.
    • c. If the marker moves slower than the object, the FOV is too large.
I messed up with the parameters, what can I do?
Press "menu" button, select "Restore default".
Why are these marker shaking all the time?
The source of the shaking is actually the noise from the sensors. This can not be completely eliminated.
However it can be improved if you keep away from strong magnetic field and metal objects, and calibrate the sensors when you feel they are not acting normally.
How to calibrate sensors?
Hold your phone in your hand, wave it in a figure 8 pattern for several times.