Google and Lenovo bring Tango 3D to Phone

Climax Studios tango
Climax Studios Tango Towers build a city and 5 star tower on your kitchen table.

Lenovo Tango with 3D camera
Lenovo Tango with 3D camera
Lenovo Phab 2 released summer of 2016 is the first phone with Googles Tango 3D augmented reality system. This is currently the only phone model with the tango system until Asus Zenfone AR is released in the second quarter of 2017).So what is Tango 3D AR. Tango was developed in Googles ATAP’s skunkworks group. The development team was headed up by Johnny Lee, which previously worked on Microsoft’s Kinect. Tango will allow you to record and map a 3D environment using the onboard 3D camera. Only a handful of Apps are currently available for Tango. These apps include MeasureIt(for measuring objects), roOomy Reality that enables you to visualize furniture placements, Tango Constructor an experimental developer app that demonstrates selected features of Tango. Tango Towers where you build a 5 star 3D tower in AR.

These only scratch the surface of the potential for AR using a phone hand set. Future applications will include building and landscape visualization in real-world settings. Applications to map in 3D using the 3D camera, systems GPS, gyroscope and accelerometer.


Centimeter Level Precision Coming to Cellphones

Smartphone centimeter positioning
Kenneth M Pesyna, Jr demonstrating centimeter level positioning with smartphone

Engineers at the University of Texas at Austin have now developed a cheap GPS system. Using a $5 antenna and software they developed and a Samsung Galaxy phone they were able to map in 3D accuracy of two centimeters. The development team now has a startup, Radiosense LLC, to further evolve the technology. They are working with Samsung to develop a low cost snap-on system, which will contain the antenna and software-based receiver. They say that the receiver should eventually be for sale at less than $50.00.

For more information:


Smart Phone GPS are they Accurate Enough?

If you are considering smart phones or tablets for field data collection you probably have this question. You should also be be asking how much accuracy you need in doing your job, and is this better than your current method.

Trimble GPS R8

Survey grade GPS, like this Trimble R8 above, has accuracies of about 2 cm and a price tag of thousands of dollars. Fortunately this level of precision is not needed for most field jobs. I you are trying to locate a utility pole, map the boundaries of a wetland, map facility locations or locating addresses accuracy of 5 – 10 meters is probably adequate.

How Accurate is a Smart Phone GPS

I have seen many claims on the internet that cell phone GPS receivers had accuracies no better than 10 meters. Those claims are out of date and misinformed. Most modern smart phone GPS receivers come with several advanced features that improves speed of acquisition and precision. They also use WiFi to indoor positioning.

First a little background about GNSS systems.  A GPS receiver calculates its position by measuring the distance between several GPS satellites. The technique used to measure the distance is called satellite ranging, in which the distance is computed from the elapsed transmission time. The receiver then triangulates a position.

There are many sources of errors in GPS the largest being the ionosphere and troposphere distortions (refractions) of radio-signals. The total error for an uncorrected signal is 10-15 meters.

Cell phones use differential corrections to improve accuracies. Most incorporate SBAS (Space based augmentation systems) such as WAAS and ENGOS for corrections. Most modern cell phones also support GLONASS and other GNSS constellations. The additional space vehicles improves the satellite geometry reducing the Geometric Dilution of Precision. Cell phones GPS receivers are assisted, which means that the satellite ephemeris data is uploaded through the internet which results in convergence in seconds rather than minutes. The accuracy of cell phone GPS is 2-4 meters.

GPS Accuracy is 2-4 meters in most current models.

Future of GPS in Smart Phones

For smart phones a major obstacle to sub meter precision is the antenna. Smart phone manufactures have restrictions on size and budget for GPS antenna. Better patch antenna could reduce sign db loss and multipath error. An improved antenna could improve accuracies 1-2 meters. Texas researchers have developed software that could reduce multipath errors from the antenna. The European GNSS system Galileo will improve GPS position to sub-meter. Precision Point positioning (PPP) technologies could become available to smart phones improving precision to decimeter range. Increase by drone, VR and autonomous vehicles will push development of centimeter precision GPS. Prices currently for L1 centimeter precision has dropped below $500.00.




Acres Walk-Through

GPS Survey Storing Polygons

This article will show you how to start a new Acres Project and how to add areas and lengths. Acres makes collecting, measuring, sharing and storing area and length information easy, accurate and efficient. So let’s get started.

In this survey we will collect the blocks from a small town in Kentucky. The blocks are defined by streets and alleys. Although this is probably not your typical job it is something everyone can relate to and is shows the features of Acres GIS collection.

Step 1. Create New Project

When Acres opens a New Project dialog is presented. By default the name will be Prj-Month-Date in this format PrjMMDD. You can change the project name or accept the default. If you want to open an existing project change the name of the existing project. We will rename the the file for this example to Augusta, the small town we are surviving.

Step 2. Collect first Polygon

Click the big plus sign on the lower right corner of Acres map screen. You can’t miss it. The button will rotate and two buttons will appear for Areas and Lengths. Click on the areas button on the top.  When the area button is clicked an “Area Mode” toast will appear and 3 new buttons will be displayed.


Point Entry Mode Buttons

  • Record. Stores a new point at the current GPS position.
  • Black Stop. Records a point at the current GPS position and closes the polygon.
  • Red Stop. Stops recording closes polygon without adding a new point.

Step 3 Record the Points

Start by walking to the first point, a blue dot will show you your current position on the map. In the control panel at the top Acres will show you the current GPS accuracy. To collect the point click the Record button, for the first point a green start flag will appear.

Now move to the next point and repeat. This will place a red survey flag. Note that the green flag has now changed to a small green circle marker. Now move to the last point a click the Black Stop button. This will add a point and close the polygon. The polygon will now be filled and closed. A green marker will show the start of the polygon and a checked flag will mark the closing point.


Step 4 Turn on SNAP

Snap will be your new best friend with data collection. This feature works like SNAP in CAD, when you are within the SNAP limit of a marker a special popup marker will be displayed indicating which marker a point will SNAP to. To activate SNAP click the SNAP Action bar button or select from Setting in the drop down menu. Toggle SNAP on and set a SNAP distance. Start a new area when the SNAP pop-up indicates you are near your last point click on the Record Button.


Step 5 Use Touch Mode to close the Polygon

With Acres never visit the same point twice. If the point is a corner or boundary for a polygon and it has been surveyed before use touch mode with SNAP to add it to your polygon. To use touch mode long click on the map screen at the desired position. Since SNAP works with touch mode corners and boundaries match precisely. To close an area in touch mode click the Red Stop Button.


Step 6 Repeat

Collect the remaining blocks with the above methods. Remember to use SNAP with Touch mode and never visit the same point twice. Now that survey is done you have a permanent record. You can export to KML and view in Google Earth or other KML viewers. KML format can also be imported into ArcGIS or other GIS programs.  You can review the Areas and Markers with Area manager and Marker Managers.

GPS GIS survey Augusta KY  KML Export

Download the Augusta KML

The Augusta KML is available for download at this link.
Augusta KML download