App for verifying survey drawing and recording building corners

“I have a survey drawing of my property and my property has metal stakes at the corner. I would like to verify the survey drawing to the stakes. I also would like to identify where the corners of my home is located on my property. What would be the best software for these requirements?”

Our Deed Calls function will let you enter bearing and distance information from your survey drawing to generate a plot in the app. You will need to know the coordinates of the point of beginning in order to correctly place the plot on the map.

Our Stakeout functions will help you get to a point or node (where the stake is supposed to be).

These functions are provided in a few of our apps, such as Deed Calls & Stakeout, iCMTGIS III and iCMTGIS PRO.

iCMTGIS III and iCMTGIS PRO also provide GPS data collection functionality that will let you record the corners of your home or any other points, lines and areas.

The important issue is what compatible GPS receiver to use to meet the degree of accuracy that you need. The GPS on iOS devices are good to about 10 meters.

GIS-grade GPS like the Bad Elf GPS and the Dual XGPS-150A claim 2 – 5 meter accuracy. You could use a GIS-grade GPS and Deed Calls & Stakeout to roughly check the stake locations against the drawing.

Survey-grade GPS devices from EOS and Geneq are quite expensive. You might be able to rent an iSXBlue Platinum or an EOS Arrow from a supplier to use with iCMTGIS PRO for best accuracy in stakeout and recording GPS points.

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Is iCMTGIS PRO compatible with Bad Elf and SXBlue Platinum?

“I have iCMTGIS pro that I used with a EOS Arrow 100. Is the software also compatible with the Bad Elf and SXBlue bluetooth gps units. I have a mapping project that only requires meter accuracy and wanted to use the Bad Elf Surveyor.”

Yes, iCMTGIS PRO will work with any GPS unit that is compatible with the iOS devices, including Bad Elf and SXBlue Platinum Bluetooth GPS. With the “Enable External GPS” turned on, the app can get the GPS position data directly from the Bad Elf GPS or the SXBlue Platinum GPS.

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.