I have an iPad Air and I’m considering purchasing a better quality gps antenna to connect. Will this app (Deed Calls & Stakeout) support an external antenna like the bad elf surveyor?

Our iOS apps support external GPS receivers that are compatible with the iPad. The Deed Calls & Stakeout app will get the GPS position data that the Bad Elf Surveyor sends to the iPad.

According to the Bad Elf GPS manufacturer, “The Bad Elf GNSS Surveyor delivers ~1-meter positioning out of the box to the iPad for use in GIS, mapping, agriculture, and survey activities.”

Our iOS apps do not provide differential correction capability.


Questions about the Deed Calls & Stakeout app for iPhone and iPad

“I’m wondering if your Deed calls and stakeout app can be used to enter the deed calls in the office, then travel to the site to establish the starting point with the phone’s GPS? Also, do the deed calls have to entered directly into the app or can it import a text file? Finally, once the deed plot is established in the app, is there a way it can be imported and viewed in Google Earth.”

1. The Deed Calls & Stakeout app can help you stake out each node on the deed plot created by entering the deed calls in the office. iPhone’s GPS does not provide high accuracy. Some external Bluetooth GPS receivers, such as the Dual XGPS 150A, Garmin Glo and Bad Elf Pro claim 1-3 m accuracy. Higher accuracy ones like iSXBlue II GNSS and EOS Arrow are in the high price range.

2. Deed Calls & Stakeout can open a .dcf file. The deed calls you enter into the app are saved in a .dcf file, which is a text file that can be viewed and edited. Therefore, you can follow the same format to prepare a deed calls file for this app to open. Make sure the angle and distance unit settings in the app match those used by the deed calls.

3. Deed Calls & Stakeout does not provide KML export. It will export to DXF, which can be converted to KML. For details please see our blog article at this link.

GPS accuracy on an iPhone, iPad or iPad Mini

We have received many inquiries about the GPS accuracy on various models of the iOS devices. This is a question for Apple to answer, but the coveted information is nowhere to be found in the product specs.

In general, consumer-grade devices that are sold separately, or the GPS built into some PDAs, the iPhone or the iPad, are not of high accuracy, but can be used to satisfaction for determining larger acreages.  Point position accuracy generally improves if you log a number of GPS fixes at one location then have the average value computed. Such functionality is provided by iCMTGIS II and iGPSGIS II.

The accuracy provided by consumer-grade GPS can range from 1 m to 20 m, depending on the device and the conditions under which the measurements are made. The iPad Mini with cellular and the newer iPhone models provide GLONASS capability. These will offer better GPS position accuracy than the older models.

A number of consumer-grade GPS devices claim 1-3 m or 3-5 m, accuracies. Some of them are compatible with the iPhone and iPad (e.g. Dual XGPS150A, Garmin GLO GPS + GLONASS, Bad Elf GPS PRO) . We heard that there will soon be external Blue-tooth GPS devices with sub-meter accuracy available for use with the iPad. However, keep in mind that better accuracy usually comes with a higher price tag.