Choosing a GPS is not always a simple task. It depends a lot on what you intend to do and the conditions under which you are doing it. Generally, the quality of GPS range from hobbiest to survey-quality devices.
For most stuff that does not require exact point accuracy and precision, most of your hand-held garmins, and even some phones and such will do fine. However, if you are needing 95% CI data for each point, you will need to use a much more expensive unit (Say the old Tremble XL or XM). If you require surveyor-quality, you are getting way up there. Now, the side of the box will tell you the precision of the instrument, however, that is the precision under the absolute best situtation when there are no clouds/overcast, the satelites are perfectly distributed in the 4 quadrants of the sky, and you are on a flat plane with no birds, bugs, or planes flying over. This is why I mentioned the 95% CI data. In that case, you would need to collect something like 180 data points at each location to get to 95% CI. You can geocorrect your data using several methods, or you can use a waystation to correct your information. However, for most uses, a GPS is intended for landscape studies and not microscale studies. YOu log the site, then you measure within the site using traditional methods. OF course, you can use the GPS for these microscale measurements, but if you under a lot of tree cover or have a lot of clouds, or yoru sats are in weird positions you will find your data to be fuzzy, but still usable (usually). If you are just trying to get within a stone's throw of your site, then I would just get a basic garmin used by geocachers and such. IF you need higher quality, then its time to talk to the sales people at tremble and find out what suits your needs. I used to have a nice garmin GPS that was also a palm pilot, and it worked pretty nice. ALl the trembles are also handheld computers. However, I am not super-famliar with the new phone GPS as far as how accurate/precise they are. My bet would be not very compared to the actual research-grade unites. I hope this is useful for you to make a decision. On Mon, Apr 4, 2016 at 5:24 PM, Merav Vonshak <[email protected]> wrote: > Hi all, > I would greatly appreciate your input on a handheld GPS device. I’m looking > for a GPS device that would allow me to navigate to my field sites, including > uploading plot locations from Google Earth or ArcGIS and viewing them in the > field, over an aerial photo of the site. I will also need to record data > points. I’m considering using an iPhone 6 or a Google Nexus 9 device, > wondering about the pros and cons of each options and the app I should use in > case I choose the iPhone or the Nexus. > Thank you! > Merav -- Malcolm L. McCallum, PHD, REP Link to online CV and portfolio : https://www.visualcv.com/malcolm-mc-callum?access=18A9RYkDGxO “Nothing is more priceless and worthy of preservation than the rich array of animal life with which our country has been blessed. It is a many-faceted treasure, of value to scholars, scientists, and nature lovers alike, and it forms a vital part of the heritage we all share as Americans.” -President Richard Nixon upon signing the Endangered Species Act of 1973 into law. "Peer pressure is designed to contain anyone with a sense of drive" - Allan Nation 1880's: "There's lots of good fish in the sea" W.S. Gilbert 1990's: Many fish stocks depleted due to overfishing, habitat loss, and pollution. 2000: Marine reserves, ecosystem restoration, and pollution reduction MAY help restore populations. 2022: Soylent Green is People! The Seven Blunders of the World (Mohandas Gandhi) Wealth w/o work Pleasure w/o conscience Knowledge w/o character Commerce w/o morality Science w/o humanity Worship w/o sacrifice Politics w/o principle Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
