GPS for plant locating

[metalfish]

I'm trying, unsuccessfully, to work out what kind of handheld GPS I need for accurately mapping the location and spread of rare wild plants on the reserve where I work. Does anyone have any suggestions on what I do or don't want.
I need it to be accurate to a foot or less.

[Harry Eales]

Originally Posted by metalfish

I'm trying, unsuccessfully, to work out what kind of handheld GPS I need for accurately mapping the location and spread of rare wild plants on the reserve where I work. Does anyone have any suggestions on what I do or don't want.
I need it to be accurate to a foot or less.

Hello Metalfish,

I don't think your going to get the accuracy you need with any GPS that's on the market. The Military may have something that good, but I doubt if anyone else has a hand held item that accurate.

A GPS's accuracy depends on how many satellites it can pick up at any one time, the more satellites in view the more accurate the handsets are but most are not accurate to more than 7 yards or so. Working in valleys and in woodlands can seriously effect the accuracy of any GPS as less open sky is available for the unit to receive a satellite signal.

In general terms the more accurate an instrument is, the more expensive it is, Sod's Law.

Harry

[Jim Ford]

Originally Posted by metalfish

I'm trying, unsuccessfully, to work out what kind of handheld GPS I need for accurately mapping the location and spread of rare wild plants on the reserve where I work. Does anyone have any suggestions on what I do or don't want.
I need it to be accurate to a foot or less.

You won't get one accurate to a foot - 3 meters is the best I can get!

You could try asking on a newsgroup/usegroup eg. alt.satellite.gps

Jim

[metalfish]

thank you folks,
this is the conclusion I am coming to too.

Measuring stick it is then!

[bigdave60dog]

Yeah! I`m having exactly the same problem only with inverts. B4 GPS systems we got as close as we could with a map ref, then used a descriptions of identifiable features. I am still doing that but using a hand held GPS instead of a map.
You are working with fixed boundaries. In that situation a grid system has always worked OK.

[Dorts]

Hi Metalfish.
One way you might consider, along with GPS, is that which a County Recorder I know is using; that is to draw a detailed map of the reserve using 'Microsoft Word', and then entering the location of individual plants. One map per plant species.
This method has been so useful that it is now being used on other reserves. Though of course the initial surveying to draw the 'definative map' will take some time, but once completed it can be used for many years and by many people.
Dorts.

[Johnny Redgate]

Originally Posted by Dorts

Hi Metalfish.
One way you might consider, along with GPS, is that which a County Recorder I know is using; that is to draw a detailed map of the reserve using 'Microsoft Word', and then entering the location of individual plants. One map per plant species.
This method has been so useful that it is now being used on other reserves. Though of course the initial surveying to draw the 'definative map' will take some time, but once completed it can be used for many years and by many people.
Dorts.

I drew maps for a management plan in Word once and "never again" is the phrase that springs to mind. I'm lucky to have to have Mapinfo GIS available. I wonder if there is there a cheap basic GIS programme you could use.

[Meta menardi]

Originally Posted by Johnny Redgate

I drew maps for a management plan in Word once and "never again" is the phrase that springs to mind. I'm lucky to have to have Mapinfo GIS available. I wonder if there is there a cheap basic GIS programme you could use.

Try Mapmaker, there is a tutorial on the site that shows you how to use it with Google Earth. I have never used it for a serious job, but it looks quite useful.

[Johnny Redgate]

Originally Posted by Meta menardi

Try Mapmaker, there is a tutorial on the site that shows you how to use it with Google Earth. I have never used it for a serious job, but it looks quite useful.

That sounds interesting. I'll look it up.

[bigdave60dog]

I have just remembered. Archaeologists "3D" finds situ. They have a gismo that
records accurately the height above -or below- sea level as well as the exact position horizontally then send the data to a nearby laptop.
They then have computer programme that will graphically reproduce the whole site with finds in three dimensions. Just imagine what you could do with one of those systems.
Dave