Field Estimates

Anywhere is walking distance, if you've got the time. - Stephen Wright

How many hours you have left until sunset?



Face the western horizon and stretch out your hand to the sun. Keep your arm straight but bend your hand so that your palm faces the sun and your fingers are horizontal. Tuck in your thumb. Align this one hand with the sun, and then bring each hand below the other in this fashion until you reach the horizon. Four fingers equals about the space that the sun travels in an hour. Thus, you can estimate how many hours until sunset. Depending on terrain, you still have usable light for approximately 45 minutes after the sun touches the horizon.


Sound


Sound travels at approximate the speed of 1082 feet per second. Multiplying the number of seconds by 1082 will give you the distances in feet.



Depth


Measure the time in seconds between the moment when you drop a stone and the moment where you hear the stone hit.


0.5 sec = 3.28 ft.
1.0 sec = 16.4 ft.
1.5 sec = 36 ft.
2.0 sec = 62.3 ft.
2.5 sec = 98.4 ft.
3.0 sec = 144.3 ft.
3.5 sec = 196.8 ft.
30 Inch Step

30 inches is the average step for most people. A double step (each time the same foot hits the ground) is 60 inches or 5 feet, so 66 double steps =330 feet or 1 portee. So 16 portee = 5,280 feet or 1 mile.

Distances appear shorter

  • The terrain is flat.
  • Weather is real clear (after rain or storm).
  • Just before and just after the sunset.
  • If you observe over a water or snow area.
  • If there is a colour contrast between the object
    under observation and the background.
  • When we observe from a high point.

Distances appear longer


  • When the terrain is rough.
  • If there are shadows or fog.
  • At sunset the object observed is lacking contrast.


Military Distances


In the German army the rules given to judge the distances are:

  • At 164 ft. - One sees clearly they mouth and eyes of a man.
  • At 328 ft. - The eyes look like dots.
  • At 656 ft. - We still see the buttons and the details of the clothing.
  • At 984 ft. - We still distinguish the face of a man.
  • At 1312 ft. - We see the legs moving.
  • At 1640 ft. - We still can distinguish the colour of the uniform.
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