Field Data Collection Best Practices
What does good field techniques mean? GPS receivers perform best when they have a clear view of the sky from the horizon to directly above and a full 360 degrees around them. Sometimes that is not possible because of natural world items like trees, buildings, people, etc.
However, you as the data collector can block satellites too. A little planning goes a long way to ensure the point you capture will be as accurate as it can be. How does one use the Bad Elf receiver to get the best field data?
- Make sure that the Bad Elf Receiver is held horizontally. The antenna is just below the display and it works best when the LCD is pointed directly up to the sky.
Don’t collect GPS data with the Bad Elf on a lanyard. Although this is convenient for carrying, having it close to your body generally ensures some part of the sky is blocked by you.
- If you need to be close to the receiver, get it above your head or any obstruction like fences, vehicles, and bushes. There are hats with pockets in them that can be very effective. Alternatively, a simple photography monopod with a flat surface on the top is a great way to get the Bad Elf receiver above your head.
- Turn on your device before you start collecting data in the field. Ideally if the device has been on recently or you haven’t moved to the next county, the Bad Elf receiver should be able to get optimal positions in 3-5 minutes. If you are traveling more than 25 miles away, turn the device on before you get to your destination. The process of turning on your device before you need to use it ensures that it can perform its best without a lot of waiting for it to startup.
- Allow the Bad Elf to settle. Bad Elf devices will tend to produce a better position if they can be left alone for a minute or two in a fixed spot. For example, the Bad Elf GNSS Surveyor requires settling to achieve its best results.
- Understand where GPS reception isn’t that good. I mentioned GPS devices like to see a lot of sky. Certain conditions are challenging for GPS devices such as deep canyons, being surrounded by tall buildings, being near large metal structures, and tall forested areas. One should expect that performance will degrade in these situations. You may be able to get GPS inside a building but don’t expect it to be accurate.
- What about using the Bad Elf in the rain? Cloudy weather and rain can affect the performance. Most importantly, you will want to protect your devices. A Bad Elf receiver is not affected by thin plastic. A quality ziploc bag or plastic food container will protect the Bad Elf from rain quite satisfactorily.
- Finally, learn how far your mobile device can be from the Bad Elf receiver before it disconnects. Some devices have excellent range up to 30 feet, other devices may only work up to 10 feet away. Before you start collecting data walk away from the Bad Elf receiver a few times so you can learn what this distance is. Once you know the distance where the connection drops you can avoid annoying disconnections and reconnections.
Familiarizing yourself with using your data collection software and the best practices for using the Bad Elf receiver will certainly improve your data collection experience. Some learning will be trial and error. Having a bit of extra knowledge most certainly will help you more reliably collect quality GIS data for your organization.