Sometimes it happens that your track recording is faulty - it is inaccurate, contains "bumps" or "bounces" or is inappropriately shortened when a part of it is missing. All these bugs are result of Locus Map receiving bad GPS data from your device - mobile phone or tablet. In this article, we'll discuss reasons of this, how to prevent it and how to fix wrongly recorded tracks.

What is bad GPS data?

We use the term to describe any circumstance where Locus receives location data that does not accurately represent your activity. Bad GPS data can result in your tracks having missing or extra distance recorded or recorded inaccurately,  inaccurate elevation values (gain or profile) and more.

Reasons and effects of this are obvious: your device may have simply lost a connection to GPS satellites and did not record any data - your recorded track shows straight lines ignoring paths or roads on map. Or, your device may have recorded trackpoints that deviate from your true path.

Typical examples:

Why does it happen?

Before we mention environmental reasons of receiving bad GPS data it's necessary to realize that Locus Map runs on personal Android devices equipped with GPS units of which data measuring is far from perfect; in fact, there is some degree of error inherent in any GPS recording. Different devices do simply have different qualities of GPS hardware and software - meaning that even if your device is working at its peak performance, there will always be a margin of error in the accuracy of its recording.

Mobile devices and satellites overhead communicate with extremely fast signals requiring precise detection and any slight inaccuracy in the signal's reception, or disturbance to the signal itself, can translate to a significant dislocation of your reported position. Therefore, environmental factors such as dense trees, steep hillsides, tall buildings, or even heavy cloud cover can impact or even interrupt the travel of the GPS signal between your device and the satellites.

Can we prevent this?

We can't advise you to avoid environments that are going to be problematic for a GPS signal - dense forests, canyons, hill sides. That would be against the purpose Locus Map has. However, we can recommend:

• to use a hi-tech device that can communicate with all available positioning networks - GPS, Glonass, Beidou and Galileo. The more satellites visible for your device above your head, the more accurate positioning
• make sure your device is mounted/carried as high up and unobstructed as possible, instead of buried deep in a pocket
• set up your Locus recording profile effectively - GPS accuracy tolerance, time and distance intervals of recording trackpoints. You always have to find a compromise between smoothness and accuracy of the recording. Don't set up too short intervals (too much data with higher risk of deviations). On the other hand, too long intervals result in a shortened track with approximate progress.

How to fix bad track recording?

Most of malformed tracks can be repaired in Locus track editor. It can be launched by tapping "Modify track" e.g. in detail screen of the track:

• with track editor, you can fix an inaccurate track - just re-position wrongly located trackpoints:
  
• complex deviations (trackpoint clusters) can be cut out of the track:
  
• single GPS bounces consisting of a few or just one deviated trackpoint can be deleted:

Issues with GPS data and accurate location belong to the most often asked at our helpdesk. Hopefully this article can help you understand this topic and give you some advice.

Michal Stupka

Illustrations by author and Strava 

Článek Issues with GPS? Check a few tips how to tackle them. se nejdříve objevil na Locus Map - mobile outdoor navigation app.

The most colorful outdoor season of the year is here. To make it more enjoyable for you, we prepared this new version with two  major novelties: handy Route Planner and Track Editor. There are of course some other nice improvements on top.

Route planning easier as never before

Although the vast majority of modern android phones have large screens, planning routes on a mobile is still not a comfortable matter. We have decided to change it. First of all, we completely re-designed the route planner screen.

Less buttons, better functionality

There is everything you need for quick and intuitive route planning:

1. drawing mode  - here you can choose between manual drawing and automatic route rendering with routing profiles (bike, walk, car ...)
2. add/remove  routepoints
3. back/forward - you can move in the steps of your drawing
4. zooming buttons and the button positioning you in the center of the screen (centering button)

Bottom bar displays basic route statistics -  distance, positive and negative elevation. The bar can be slid up to show the current elevation chart in the Pro version:

Fast planning with shaping points

By tapping  (add point button) you create so called shaping points  . You can add them also by tapping directly on the map. If manual mode is selected (default setting), a simple straight line is drawn between the points - this method is more suitable for easy distance measurement or for areas where routing data is not available:

The planner can create the route along the roads and paths automatically. You just need to select a drawing mode according to your activity.  Then, the route si drawn between the shaping points. If you choose walking, the route runs along footpaths, if you chose a bike the planner uses roads.

You can manage the route by freely moving of shaping points  and auxiliary points . Besides you control the elevation gain of the route in the bottom bar where the chart changes accordingly.

To navigate through certain places even during recalculation while driving, change the shaping point to the via-point - tap it and select "Change to via point". The via-points, marked , can be named - the name will then be heard in the voice navigation.

You can also add LoMap points of interest (POIs) to your route. Tap the point and select an option where the point should be located - at the start, in the middle or at the end of the route. Such a point is automatically marked as via point.

If you have your own points in Locus - your places of interest, geocaches etc. - or points that have to be especially defined (e.g. addresses), you can add them to the route as well. Open the route menu (top bar right corner) and select Add point:

Then, select My points if you want to pick from your own database or other ways of point definition:

Check detailed statistics for better results

Detailed statistics and elevation chart of the route plus estimated Travel time can be found in the route menu as well.

You can navigate along the new route simply by taping the Navigate button.

When your planned route is finished, it's necessary to save it. In Route menu, tap Save route, name it and select the folder and activity.

If you want to abort all your editing, tap "Delete route" in the route menu.

Track editing with cool tools

Another good news is that we bring more options to edit your track or route:

1) to re-plan your route, just open it in the Route planner and go on as with a new route:

2) if you want to:

• erase part of the track
• split it in two
• or insert a gap etc.

...use newly re-designed track editor. Just tap the track on map and select "Modify track":

Cursor is placed on the spot of the track you tapped which pops up a label, showing trackpoint stats - distance from the start and from the end of the track, elevation gain etc.

•   editing tools
•   move the cursor along the track from one trackpoint to another for their precise selection.
• +  -   Zooming buttons

The editing tools allow you to:

• cut various parts of the track - inner part, from the start to the selected point or from the point to the end - useful for example when you forget to stop track recording of your the trip when you get the bike on your car roof rack and travel home.
• If you have multiple day track record, you can split it in individual days.
• You can also insert a gap for the case you traveled through a tunnel and want to hide the line connecting GPS-fixed trackpoints.

The editor allows also precise tuning of individual trackpoints - basic particles of the track. You can move them, add new or delete unwanted. Select a trackpoint, then Insert/edit trackpoint or Delete trackpoint from the Tools menu. The editable trackpoints surrounding your selection are highlighted  and auxiliary points . By shifting them you can change shape of the track:

All changes must be confirmed in the topbar.

Better user experience

We hope you'll enjoy these renewed features as much as we do. And not just them - great majority of recent changes in Locus have been made in order to improve user experience. Among others let's mention at least re-designing the point adding dialog. We rewrote all texts and added point import into it. Hopefully, this dialog is now much more comprehensible for both old and new Locus users:

And now, put your phone in your pocket and get outdoors! And don't forget to take autumn-nature-colorful-leaves pictures and share them with us!

Článek New handy Route Planner and simple Track Editor in Locus Map 3.26 se nejdříve objevil na Locus Map - mobile outdoor navigation app.