[Rhodes22-list] New Toy

[Roger Pihlaja]

Hi Everybody,

Well, I recently had my 51st birthday.  My family & relatives all gave me Cabela's gift certificates this year plus I already had a couple more gift certificates.  I decided to order an Osprey Laser Rangefinder.  The thing that caught my eye about this model is the phenomenal 1600 yard (0.91 statute mile) range against a reflective target!  It also has a built-in 7X50 binocular.  This combination of features should make it useful as a navigational tool.  Most targets of interest on the water are considered "reflective" , i.e. another boat, a buoy or day mark, a lighthouse, water tower, or other landmark.  It should be possible to determine a position fix from a single landmark by shooting a compass bearing & ranging the distance with the Osprey.  There are many situations on the water where there are not multiple landmarks available to triangulate a position fix.  It would be better if the Osprey had a built-in bearing compass. But, I don't mind having to take two separate measurements when it gives me more options to determine an accurate position fix without GPS.  With a distance ranging accuracy of +/- 1 yard, my new Osprey rangefinder should also be useful in racing situations or any other time when you'd like to know whether you are slowly closing the distance with boat up ahead.

The Osprey also has a 5 - 1000 mph speed measurement function.  It's sort of a civilian version of a police laser speed gun.  It doesn't use the doppler effect like police radar speed guns use.  Instead it computes speed from the change in consecutive distance measurements along with a built-in time base.  I've used it with my inflatable sport dingy against a stationary target to determine the top speed was 19 mph with only me aboard.  However, the accuracy & resolution is not sufficient for detecting the tiny speed differences between racing sailboats, especially when the Osprey is on a moving boat shooting another moving boat.  Assuming I ever get another engineering job, I can envision work-related applications for remotely measuring line speeds or machine speeds in places that are inaccessible due to high temperature, tight machine clearances, or other hazards.  Other applications may come to mind after I've played with my new toy for awhile.  It's intriguing to have the capability to measure velocity remotely.

Roger Pihlaja
S/V Dynamic Equilibrium