Questions about iCMTGIS II

“1. Does the app have the capability to record bread crumbs? The App store indicates that it can record my track, so I assume this is the same capability. 2. For the record my track capability, can the lat, long, date & time all be exported? If yes, which formats are available?”

1. The iCMTGIS II app has the ability to record Points, Lines and Area Features. It can export the latitude, longitude and elevation to Shapefiles, but not date and time. For Line Features and Area Features, our apps only record the position of the first node. If you record the route as a Line Feature, you can record the waypoints as “nested” points along the Line Feature.

2. “Track” usually refers to a continuous recording of wherever you have been while navigating or recording GPS Features. iCMTGIS III has the capability to record a track. iCMTGIS II does not. However, for Line Features, Area Features and Tracks, our apps only record the position of the first node. Therefore, if you would like to have coordinates along a track, you will need to record the position of waypoints as Point Features. Or you could record the route as a Line Feature and record the waypoints as “nested” points along the Line Feature.


Missing GPS track

A Forester GPS GIS II user wrote:

“last couple times out in the field I find with GPS ‘ on’, Collect ‘on’ and Tracklog ‘ on ‘ I am NOT getting the usual visible track. . . . I messed about in the Coordinates, Patterns and Nodes and, for the MOMENT, it seeemmzz to be Working!”

If the color of the Tracklog line pattern was set to be the same as the background, then there would not be a contrast to make the track stand out. Another possibility is that an Area Feature Topic with low
transparency was placed above the Tracklog layer and obscured it.

Need app for lime spreading

“We are looking for a app that can assist us with our lime spreading operation……the app we are looking for would enable us to overlay a map with grid lines, these grid lines would ideally run North/South and East/West, and would need to be able to be adjusted/calibrated to suit the coverage width of our spreader, the app would then create a track that shows what areas we have covered.”

Our iCMTGIS III and iCMTGIS PRO for iPad and iPhone will let you directly load a GeoTiff file to use as a background map. These apps can also display the built-in Apple Map when wi-fi connection is available.

Farming GPSGIS II for iPad will display the built-in Apple Map via wi-fi connection. If you have PC-GIS X, you could use it to convert GeoTiff, MRSID and ECW map files to .pim files that can be used by Farming GPSGIS II as background maps.

You can use the above apps and a compatible GPS to record the perimeter of the area you will be working with. Or, if your farm boundary can be clearly viewed on the background map, you could digitize its perimeter. This will create an Area Feature. Then you can create grid lines over the Area Feature at the desired spacing in the North/South and East/West directions (or any other direction).

The above apps also provide a Line Stakeout function that can help the spreader stay on the grid lines.

With GPS turned on, you can use the app to create a track that shows where the spreader has been. This will be a Line Feature.

The important issue, however, is the desired accuracy. The GPS provided with iPhone and iPad devices are not accurate. Many of our customers purchase an external GPS receiver that is compatible with the iPhone and iPad devices. The Dual XGPS-150A and Bad Elf GPS claim 1-3 meter accuracy. iSXBlue and EOS Arrow GPS receivers can provide submeter accuracy, but they are pricey.

I want to keep my tractor in line and also record the track

You can use iCMTGIS II or iGPSGIS II in conjunction with Stakeout iCMT. iCMTGIS II and iGPSGIS II will record the GPS track in the background while you use the Stakeout iCMT to keep your tractor in line.

With your iPad and a reasonably accurate external GPS receiver, you will be able to use iCMTGIS II or iGPSGIS II to record the locations for points, lines and areas. You will be able to drive around a land plot and map the Area Feature for the land plot. You could record a tractor path as a Line Feature. Or, you could turn on the Tracklog and have the track automatically recorded as you move along.

Stakeout iCMT provides the Point Stakeout and Line Stakeout functions. The Line Stakeout function will show how much you deviate from a path. You can either digitize that path in Stakeout iCMT, or get a previously recorded Line Feature or Area Feature from iCMTGIS II or iGPSGIS II.

When you tap the Settings button in a stakeout screen, you will see the option to display a message and/or issue a beep when you are within the distance specified in the Tolerance field. Therefore, if you set this tolerance value to be 3 ft, then as long as you are within 3 ft of the line you will hear beeps or see a “Target!” message flash on the screen. When you are out of bounds, the beeps will stop and you won’t see the “Target!” message.

That said, the accuracy of the stakeout and the recorded track or Line Feature will depend on the accuracy of the GPS receiver used. For sub-meter accuracy, you will need to budget for a GPS receiver like the iSXBlue II.

Recording the track or the flight path

For certain field applications it is desirable to record the track of where you’ve been on the ground or in the air. You know that you could use your iCMTGIS or iGPSGIS to record such a track as a Line Feature. What if you also need to record other Features in addition to your  track?

With iCMTGIS you could store “nested” Point Features without interrupting the Line Feature for the track.

With iGPSGIS, you could stop the recording of the track to record the other Features then record a new Line Feature for the next segment of the track. Later you could use PC-GIS to join the separate line segments together.

The iCMTGIS II and iGPSGIS II to be released in the near future will provide a dedicated function to record the GPS track in the background, regardless of what Features you record in the foreground. It will also let you toggle the track recording on or off as you please.

For airborne applications, we recommend the CMT PC-MAPPER AI 4.0, which will run on a Windows PC, notebook PC or tablet PC, and provides functions specifically designed for airborne surveys and data collection.