Using GPS to measure area

[LwnmwnMan2]

Can anyone tell me if you can use a GPS to measure the size of an area? Say you want to measure a football field and see how many square feet there is? Or wouldn't it be very accurate since most can only get you to within 3-4 feet of a "location"?

Thanks,
Lwn

[Surface Tension]

I've done it to get a rough idea on property lines for hunting land. All you need is one corner to start at. Take a bearing with a compass and use your GPS's function Distance Traveled. Or if you have mapping software you can measure distance and set directions then upload the corners into your GPS just like you would in charting a route. If this isn't close enough then you'll need a transit and steel tape measure.

[LwnmwnMan2]

Basically, I'm looking for something where I can measure out square footage for large areas of land. I control unwanted weeds and fertilize properties and am looking for something that takes the place of my wakling stick/wheel. The only problem I see is, if I'm off 3-4' each corner, and I'm measuring out 2-3-4 football field-sized areas, my measurements could be off dramatically. Anyone know of something else to use?

Thanks,
Lwn

[PerchJerker]

I have a Garmin GPS V, which has a feature that lets you measure the area of whatever you walk around. I've used it on food plots. After completing a lap around the edge of the food plot, the unit will tell you the area and display the shape on the screen (using all the tracks it saved).

The issue Iis that everytime I've done this, it gets 1 or 2 "bad" readings, which it counts in the perimeter. This throws the shape off and and adds or takes away area.

To determine area for fertilizer, lime, herbicide, seed, etc., I use my rangefinder and shoot yardages, diagram my food plots, break them down to squares, rectanges, triangles, etc. and calculate yardage that way. While playing around with the gps I usually get a measurement that's pretty close to my hand calculations, but I'm not comfortable enough with the gps to just rely on that.

I haven't tried this since last year. I don't know if the DOD has made any changes to their signal scrambling that would make it more accurate and elimate the "bad" readings that throw the area off.

Good luck.

[joshb]

good luck finding any gps that is accurate to 3-4 feet consistantly, usually if you can get within twenty feet of your exact location your doing fairly good. the whole waas thing is a joke, since waas sattelites are all near the equator so they have to pull some pretty tough angles to triangulate in the northern states. really they're no better than the others, and you have to be uplinked to them for at least a half hour straight for them to even work. in all if you need to be exact use the wheel but if you can afford some margin of error then gps's can really be a help. also in my own experience gps's don't really work the best moving at walking speed, to get a decent reading you should be moving faster than just a walk.

[PerchJerker]

Been a while since I tried this, but I think my gps let me enter how often I wanted it to take a reading when I was calculating area. The faster you move or the longer the interval, the fewer points it reads to calculate the area - the opposite if you move slower or set shorter intervals between readings. I got a more accurate drawing of the shape if I had more points, but there was still the issue of a couple bad readings. But a few bad readings had less effect if there were more data points than if there were a few bad readings and fewer data points.

Bottom line - kind of fun to play around with, but frustrating that it's not more reliable.

[Surface Tension]

I had my GPS out today and noticed an EPE of 50 - 150 and I had good coverage. Not to good for estimating your sq footage.

[LwnmwnMan2]

Thanks for the info guys...... guess I'll just keep using my walking wheel.

Lwn