GPS Versus Landmarks
How much more precise are we thanks to Einstein and the development of rocketry?
I've been taught that before the proliferation of the Navigation Satellite Timing and Ranging Global Positioning System (NAVSTAR GPS) when you took a sample from a site, such as aquatic invertebrates from a watershed, the standard procedure was to name the site as best you could which mostly meant putting the name of the body of water down or describing local landmarks. As I'm sure you can imagine, this just isn't a very precise way of marking where you took a sample from.
As GPS the technology has developed and as the satellites that enable its precision have been launched into orbit in greater and greater numbers, resulting in greater and greater precision, policies have also enabled non-military use of GPS to be more precise by turning off civilian uses' selective imprecision. (You can read more about the history of GPS here.) The technology behind GPS is becoming so popular and widespread that there are now multiple systems competing with GPS. All of this is to say: Using GPS for marking sites is very precise, often to within a couple of meters barring errors.
There are two things I want to note about all of this. The first is that the distances involved in using GPS are so vast that relativity comes into play; Einstein's work was essential to actually being able to use satellites to mark distances and positions on Earth. The second is that citizen science is becoming an incredibly popular tool for many scientists and especially for ecologists who are well-served by having a vast network of data points to draw upon. The beauty of citizen science's synergy with GPS is that you don't have to know anything about GPS, you don't even need to know it exists, to have it in your phone and to have your phone mark a site when you send in a data point.
Wow. So we are all insanely accurate citizen scientists just waiting to happen then, right?
Mostly, but not entirely.
I have personally spoken to professors who utilize GPS for their work, it's insanely useful for tracking distributions of species or distributions of anything really, that are unaware of certain pitfalls of GPS. An example of such a pitfall is Multipath Error. Multipath Error occurs when the signal between the satellites and your GPS unit is blocked from reaching your unit in the most direct way. Multiple signals are sent and the first one your device receives is the one it uses, if that isn't the most direct path from the satellite sending it then you end up with problems in distance estimation and as a result are less accurate. You can easily go from an accuracy of 2-3 meters to 10-15 meters. That accuracy matters, it can be a difference of an order of magnitude.
It is then not impossible to suppose that citizen science data that relies on GPS is probably not as accurate as it could be due to operator error on top of everything else, it is certainly a natural assumption that some errors that could be fixed, aren't.
Well. I suppose I have somewhat of an answer to my question. We are much more precise thanks to Einstein and rocketry and lasers and all that, but we aren't as precise as we think we are.
See you later.
I've been taught that before the proliferation of the Navigation Satellite Timing and Ranging Global Positioning System (NAVSTAR GPS) when you took a sample from a site, such as aquatic invertebrates from a watershed, the standard procedure was to name the site as best you could which mostly meant putting the name of the body of water down or describing local landmarks. As I'm sure you can imagine, this just isn't a very precise way of marking where you took a sample from.
As GPS the technology has developed and as the satellites that enable its precision have been launched into orbit in greater and greater numbers, resulting in greater and greater precision, policies have also enabled non-military use of GPS to be more precise by turning off civilian uses' selective imprecision. (You can read more about the history of GPS here.) The technology behind GPS is becoming so popular and widespread that there are now multiple systems competing with GPS. All of this is to say: Using GPS for marking sites is very precise, often to within a couple of meters barring errors.
There are two things I want to note about all of this. The first is that the distances involved in using GPS are so vast that relativity comes into play; Einstein's work was essential to actually being able to use satellites to mark distances and positions on Earth. The second is that citizen science is becoming an incredibly popular tool for many scientists and especially for ecologists who are well-served by having a vast network of data points to draw upon. The beauty of citizen science's synergy with GPS is that you don't have to know anything about GPS, you don't even need to know it exists, to have it in your phone and to have your phone mark a site when you send in a data point.
Wow. So we are all insanely accurate citizen scientists just waiting to happen then, right?
Mostly, but not entirely.
I have personally spoken to professors who utilize GPS for their work, it's insanely useful for tracking distributions of species or distributions of anything really, that are unaware of certain pitfalls of GPS. An example of such a pitfall is Multipath Error. Multipath Error occurs when the signal between the satellites and your GPS unit is blocked from reaching your unit in the most direct way. Multiple signals are sent and the first one your device receives is the one it uses, if that isn't the most direct path from the satellite sending it then you end up with problems in distance estimation and as a result are less accurate. You can easily go from an accuracy of 2-3 meters to 10-15 meters. That accuracy matters, it can be a difference of an order of magnitude.
It is then not impossible to suppose that citizen science data that relies on GPS is probably not as accurate as it could be due to operator error on top of everything else, it is certainly a natural assumption that some errors that could be fixed, aren't.
Well. I suppose I have somewhat of an answer to my question. We are much more precise thanks to Einstein and rocketry and lasers and all that, but we aren't as precise as we think we are.
See you later.
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