The ability to use FLOW in local coordinate systems is great - however there is a problem with US State Plane Coordinates.
The feet option is in International Feet not US Survey feet. States like California use US Survey feet in their local coordinate systems.
A U.S. survey foot is expressed as a fraction — 1200/3937 meters — while an international foot is expressed as a decimal, exactly 0.3048 meters. This is a small difference however, with seven digit coordinate values it makes quite a difference. About 20 feet in my case.
One solution would be to add US Survey feet in the units dialog . Right now there are only meters and feet (I believe to be international feet). And yes - I do wish we were in the metric system - it would make life easier.
The other option would be to give EPSG numbers for the coordinate systems in the Library and provide the correct combinations of horizontal datums and units. . As you probably know these codes can be found at spatialreference.org.
Thanks for the great work on the app. It helps a lot.
I can confirm that flow has usft, as I use it all the time. Also, nationally the US is moving away from the US survey foot in favor of one foot, the International foot. See here from NIST: U.S. Survey Foot. That being said, most surveyors in the US will continue to use what their respective state has adopted according to the NGS: https://geodesy.noaa.gov/SPCS/images/spcs83-legislation-feet.png. Also, there is a USFT option for CA zones in state plane NAD83 2011. See attached.
Thanks. Yes I see the option shows up in the Android version of Emlid Flow but not on the Web version.
I used the web version in the office to prepare my project for stakeout - hence the problem. The coordinates from the Autocad file were in US_ft but the Web version only offers meters or feet which introduced a significant stakeout error.
USft is in everything that I have used in Texas. What EPSG are you using? The USft has been officially deprecated since January 1st so hopefully our work in Land Dev and Construction will weed it out pretty quick. I know we are using it for any more asbuilts…