Wednesday, November 25, 2020

Prudent Prepping: Far Away... or Is It?

The dust has settled and the First 72 Hours have passed. Follow along as I build a long term plan via Prudent Prepping.

I recently added very good optics to my gear, and so the topic of "How do I figure out long to very long distances in the field without a rangefinder?" came up, and by long distance I mean "How far is that hill, and how long will it take to hike there?"

Luckily for me, one of my roommates is a math tutor and was able to answer the question in terms that I, the World's Worst Math Student (tm), am able to understand.  

Working It Out

My friend started out by telling me how easy it is, using words like Cosines and Tangents. After doing my deer in the headlights impression, we got out a piece of paper and made these really easy to understand pictures. 

This is what was drawn for me:

 I can do this!

First things first: I was told that the more accurately the angles can be measured, the better the distance calculation will be. 

  1. In the drawing, aligning the start point with the target and then laying out a 90 degree angle for the base is important. 
  2. Measure as accurately as possible along that 90° angle to establish the base, shown as X.
  3. Here is where being able to get good angle measurements is important, since this will give you the vital number that plugs into your distance equation.

So the answer to the question of "If I know the distance to point X, how can I find the distance to point Y?" is to take the tangent of the angle between X and Y -- this is known as an azimuth -- and multiply it by the known distance. In other words, Distance to Y = Distance to X times the Tangent of the Azimuth. 

My next question was "How do I figure this equation?" and I was told use my phone's calculator app to get the tangent. Looking at my phone and not finding any key marked 'Tangent', I was told to hold my Android phone sideways. 

Yeah, I didn't know there were other functions. 

So, after looking at the diagram and doing some simple calculations with my phone*, I think I will be able to estimate long distances easily. I will need to learn how to use a lensatic compass to find an azimuth, but that is a cheap and worthwhile addition to my gear. Guess what I'm doing next week?

*This can be done without cell service or a phone, if you have a small solar-powered calculator with the proper function keys.

Recap And Takeaway

  • Having a disorganized mind and plenty of smart friends helps me solve lots of problems!
  • Nothing was purchased this week, but there are several items to be reviewed as soon as supporting parts arrive.
* * *

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NOTE: All items tested were purchased by me. No products have been loaned in exchange for a favorable review. Any items sent to me for T&E will be listed as such. Suck it Feds.

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