VTB Vapor-Trail Ballistics

RFSAT Limited

About this app

PROBLEM ADDRESSED

The biggest challenge in competitive sport shooting has always been estimating the wind between the rifle and the target. Classical approaches based on measuring wind conditions at the shooting location lose accuracy as the distance increases, since wind often changes dramatically along the path depending on the environment.

SOLUTION

The VTB application solves this problem by offering means to assess changes in cross wind conditions along the full path between the shooter location and the target.

It turns the smartphone into a wind-measuring instrument for estimating corrections in rifle scopes. User mounts the phone on the rifle scope, records a shot and VTB measures crosswind from the bullet own vapor trail. Then it converts wind estimates into exact clicks to dial on the turrets.

HOW IT WORKS

Every bullet leaves a turbulence trail in the air. VTB finds the shot instant from the muzzle report in the clip's audio, tracks how that trail drifts downwind, and converts pixel motion into a real wind speed using your camera's calibrated field of view. That wind feeds a full point-mass ballistic solution, the standard G1 drag, your rifle's zero, and live atmospherics, producing a firing solution referenced to your scope's own click value.

THREE WAYS TO MEASURE

• Vapor trail: standard method for rimfire and centrefire
• Tracer: tracks burning element in flight for geometrical solution
• Pellet/slug: tracks directly the projectiles for PCP air rifles

DIGITAL AND THERMAL SCOPES

The application offers comprehensive support for ATN scopes: X-Sight 5, X-Sight 5 LRF, 4K Pro, 4K Buckhunter, X-Sight II, LTV, and the ThOR 5 thermal range, each carrying its published field of view.

Such digital scopes offer an opportunity to analyze videos recorded by the scope itself onto the embedded SD card with the correct optics geometry applied automatically. On models that enable streaming, it captures the scope video directly via Wi-Fi.

LIVE ATMOSPHERICS

The application supports reading barometer and other relevant weather data from the phone. It also allows connection with Bluetooth to Kestrel weather meters, both the DROP D3 and the 5700 Elite with LiNK, including the Ruger version, for acquiring real temperature, humidity and station pressure at the firing point.

EQUIPMENT PROFILES

The application includes a variety of catalogues:
• Ammunition: factory rimfire & centrefire loads, air gun pellets/slugs
• Scopes: Vector Optics, Vortex, Burris, Steiner, Schmidt & Bender, Bushnell, Nightforce and ATN
• Rifles: rimfire trainers and PCP air rifles

Combinations of the above selections can be saved into "Profile sets", CSV files containing a complete rifle, bullet and scope combination, allowing to switch rigs in one tap and apply previously calculated wind estimates to different profiles.

PRECISION FEATURES

• Chronograph entry, solving muzzle-velocity temperature coefficient from two measurements
• Drop calibration against published loads or measured trajectory
• Wind-scale calibration against the reference measurement
• Session averaging: the more shots, the tighter the estimate
• Per-field units: metric / imperial, chosen parameter by parameter
• Spoken corrections, so the eye can stay at the scope
• Shot history with CSV export

BUILT FOR THE FIELD

Four display modes, including night green and night red to protect dark adaptation, applied to every screen. Exposure and white balance lock the moment recording starts. Image stabilization is disabled automatically, because it would corrupt the very motion being measured.

PRIVACY

Everything runs on the device. No need for registering accounts, clouds, and without any data leaving the phone.

LEGAL CLAUSE

VTB is a measurement aid for competitive sport shooting on approved ranges. Every estimate carries uncertainty, shown alongside results. Shooter remains responsible for safe handling, backstop verification, and compliance with range rules and local law.

What’s new

Minor corrections made to the processing algorithms. The latest user guide can be found at: https://www.rfsat.com/download/VTB-User-Guide.pdf