New Posts New Posts RSS Feed - Setting LOS angle on a mobile device
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Check GunBroker.com for SWFA's No Reserve and No Minimum bid firearm auctions.

Setting LOS angle on a mobile device

 Post Reply Post Reply   Topic Search Topic Search  Topic Options Topic Options
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: February/01/2012 at 16:16
jonoMT View Drop Down
Optics Master Extraordinaire
Optics Master Extraordinaire
Avatar

Joined: November/13/2008
Location: Montana
Status: Offline
Points: 4615
I've got three other ways of doing this in Ballistica (ballistics calc for Windows Phone) - keypad (slow, old school), a dial that uses a touch gesture (fastest) and a line-of-sight setter where you aim the phone. I'm considering adding something like this as well, using the camera and an onscreen reticle. Line it up and click the button:



The coding is easy and it is accurate, but I'm not convinced it's better from a functionality standpoint and it eats battery.



Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: February/01/2012 at 16:52
Kickboxer View Drop Down
MODERATOR
MODERATOR
Avatar
Moderator

Joined: February/13/2008
Status: Offline
Points: 18344
People will like it, even if it is a battery hog... I would include it as an option...
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: February/01/2012 at 22:29
helo18 View Drop Down
Optics Jedi Knight
Optics Jedi Knight
Avatar

Joined: December/02/2006
Location: Montana
Status: Offline
Points: 5431
I am sure people will like the feature, but I do wonder how accurate those sensors really are in a phone.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: February/02/2012 at 09:11
jonoMT View Drop Down
Optics Master Extraordinaire
Optics Master Extraordinaire
Avatar

Joined: November/13/2008
Location: Montana
Status: Offline
Points: 4615
Accelerometer sensors are pretty accurate and in some phones are augmented with a gyroscope sensor (which helps filter readings while the device is in motion). But there are two things that affect accuracy as far as something like this is concerned. One is purely mathematical, the other has to do with how the device is treated.

Raw sensor readings are delivered as sine values in radians. I have to convert them like this:

   double YAngleInDegrees = RadianToDegree(Math.Asin(e.Y));

If you've ever looked at sine values, as an angle approaches 0° or 90° the values become so close together it becomes almost impossible to get a truly accurate reading. As related to a mobile device, that means if it is standing vertical in portrait mode the Y-axis value is near 90° but is constantly fluctuating. As related to a ballistics app, well no algorithm goes past the range of -60° to 60° so that mitigates the mathematical issue. You also have to institute some sort of filter to smooth out the readout.

The second problem is that the sensor may be bad or miscalibrated, e.g. the user drops the phone on a hard floor. The developer can add a calibration function. In my case, however, I actually had a sensor go bad and had to have AT&T replace the phone. It still worked for going between portrait and landscape mode, but not for this.
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Similar Threads: "Setting LOS angle on a mobile device"
Subject Author Forum Replies Last Post
DIY Aiming Device for ANGLED Spotting Scope Losthwy Spotting Scopes 0
S3 set turret set screw size shooter65 Rifle Scopes 0
I hit a good score in Mobile ! HuntMaster Firearms 3
Angled or Straight Eyepiece? Shoalwater Spotting Scopes 5
Got a question about angles when zeroing and stuff HotFudge Rimfire / Airgun 15
brightnes of angled vs straight webrehm Spotting Scopes 7
ANGLED AND STRAIGHT SPOTTER pawoods Spotting Scopes 27
Burris xtrii parallax setting jeremyvan Tactical Scopes 7
Skin / Cover for Nikon 20-60x82 angled scope legnef Spotting Scopes 0
Cool Dutch Over Set-Up Chris Farris Critter Cooking Café 4


This page was generated in 0.313 seconds.