Getting Started

BASEline is a set of tools designed to help skydivers and BASE jumpers improve wingsuit flight performance. BASEline consists of two parts:

  • BASEline Flight Computer is an android app that uses phone sensors to provide audible and visual feedback on speed and position, as well as logging data for later analysis.
  • is an interactive website to help process and analyze flight data.

Warning: Skydiving, BASE jumping, and wingsuit flying are inherently risky activities. Data in BASEline may be inaccurate, and you should not make life or death decisions based on it.

This website is an online tool for analyzing wingsuit flight data. To use this website, first you must record GPS data from your skydives and BASE jumps. If you don't have a GPS logger, check out our hardware setup guide.

Once you have tracks uploaded to you can:

  • Display your horizontal speed, vertical speed, total speed, and glide ratio during a jump
  • Display a profile view of your start performance on a BASE jump
  • Compare your start performance across multiple BASE jumps
  • Visualize a jump in 3D using Google Earth
  • Evaluate flight plans using Google Earth

Upload tracks

The easiest way to upload tracks to BASEline is to record the data using the BASEline Flight Computer app. Once you sign in using your google account, the app will sync tracks directly to your BASEline account.

You can also upload track files to the website from your computer (if you have a FlySight, for example). Once you are signed in to, you should see the upload area on your tracks page:

BASEline file upload box

BASEline currently supports track uploads from the following sources: BASEline Flight Computer, FlySight, GPX files, and some KML files.

FlySight GPS

Track page

Track statistics include things like time, location and distance metrics summarizing your track.

Cross 1:1
Distance to cross 1:1 line
Fly as far as possible in 200 meters altitude
Fly as far as possible in 30 seconds

For cross 1:1, smaller is better. For feather and kings, bigger is better.

Profiles page

The best way to compare flight profiles is by using the "Profiles" page.

By jumping repeatedly from the same exit you can build up a database of start arcs. You can see the difference between a good start versus a bad start, and evaluate terrain more scientifically. Keep in mind that many factors affect start performance, including wind, temperature, elevation, etc.

See chart help for more information.

Visualize in Google Earth

From the track page on, click "Open in Google Earth" to download a KML file with your jump data.


Time Chart

The time chart displays track data with time on the horizontal axis. Altitude, speed, and glide ratio are shown on the vertical axes. Speed is shown as separate horizontal and vertical speed components.

By clicking and dragging across the time chart you can trim the track. Trimming the track helps with removing unimportant data before and after the jump. Trimming also sets the exit point, so that calculations of time and distance are relative to the true start of the jump.

Wingsuit BASE time chart

Zoom in or out on the time chart by scrolling on the bottom time axis.

Distance Chart (Flight Profile)

The distance chart displays change in altitude and distance relative to your exit point. The vertical axis is the change in altitude relative to the exit point. The horizontal axis is the distance from a given point to the exit point.

This chart is most useful for measuring start performance in the BASE environment. As soon as you make a turn, the flight profile will no longer mean much because you are no longer flying straight away from your exit point.


The "unroll" switch will toggle between straight-line and total distance on the horizontal axis. The difference is subtle but important. The "unrolled" distance chart shows a flattened view of your flight path, measuring the sum total distance traveled from the exit point, including the extra distance covered in turns. If unroll is off, then the distance chart shows the straight-line distance from the exit point, ignoring turns in your flight path.

Total distance is more useful for skydiving, since it "unrolls" the typical flight pattern. In BASE jumping, the straight distance is more useful since it more accurately measures your start performance relative to fixed terrain.

Warning: The "unrolled" distance can be dangerous in BASE, because data errors and noise will tend to OVER-estimate your distance.

Wingsuit BASE flight profile chart

Drag the zoom slider to zoom in or out.

Speed Chart (Polar)

The speed chart displays horizontal versus vertical velocity. Diagonal lines show glide ratios of 1:1, 2:1, and 3:1. In gliding flight, this is sometimes referred to as the polar chart.

Learn you some theory from Matt Gerdes and Top Gun BASE about polar charts.

Wingsuit BASE polar chart

The polar chart is the best tool for understanding your speed during a flight. With a quick glance you can see your horizontal speed, vertical speed, total speed, and glide ratio.

Speed vector diagram

You can see a jump build up speed at the start, and how it translates into horizontal speed. It is also useful for seeing how to build up speed, and convert that into a flare.

Flare Theory

There are a number of factors that go into a good wingsuit flare, and the speed chart is the best tool for fine tuning flare performance. The key to a good flare is 1) building up total speed, and 2) efficiently converting speed into lift.

Leading into the flare, your first priority is to maximize your total (3D) speed. The secondary goal is that it's better to be closer to 1:1 glide ratio than straight headdown. This is because if you are flying straight headdown, you will first have to convert more of your vertical speed into horizontal speed before you can start turning it into a climb.

After you have built up speed, the next stage of the flare involves slowly increasing your angle of attack, to exchange speed for increased lift.

A good flare

This is a balance of factors. If you flare too quickly, you will have more drag, lose efficiency, and not gain as much altitude. If you flare too slowly, you will be subject to gravity for a longer period of time, and not gain as much altitude.


The green ellipse represents typical skydiving and BASE canopy flight envelopes. The purple ellipse represents typical wingsuit flight performance envelope. The purpose of the ellipses is to give a point of reference on the polar chart, so that it can be quickly understood, without having to directly read the speed numbers.

The baseline ellipses are based on data from over 2000 wingsuit jumps:

Wingsuit BASE polar chart

Flight Profiles

One of the most technical aspects of wingsuit BASE jumping is start performance. The key to short start jumps is knowing two things: what is your start arc, and what is the shape of the terrain. We call the shape of the terrain its "exit profile."

Exit profiles should be measured using an accurate laser range finder.

If you are verified as a BASE jumper, BASEline provides a list of exit profiles contributed by users.

Warning: Exit profiles are submitted by users, and have not been verified by baseline. Always check measurements yourself.

Flight profile with exit profile

Exit profiles can be found below the flight profile chart.