User:SchematicMapper
Background
I started off as a physicist, added a Masters in Remote Sensing, then wound up working in a photogrammetry and surveying department for a while, hence my love of mapping and aerial photo interpretation. Nowadays, I work in IT (mainly as a solutions architect), with a few sidelines.
I currently live in N4, London, and started mapping when I lived in E16, London, I am now slowly mapping the area where I am on foot with my GPS - a task that was a bit hairy at times in E16, but has got safer in N4. I'm trying to map buildings and points of interest as well as streets and street names, since I am interested in seeing even more detail in OpenStreetMap. I also take my GPS to log tracks anywhere else in the country I go.
I am also mapping parts of South Wales that I know. I grew up in Cardiff, and know the surrounding area well, so I am doing what I can to help.
GPS Devices
- Garmin#GPS_60 - this is my current GPS, and it is a very good, basic, non-mapping GPS unit. It is rugged, reasonably accurate, has good connectivity options (USB and Serial/RS-232), is very reasonably priced, and has very, very good battery life - currently, I am getting around 25 hours out of a pair of AA NiMH rechargeable batteries in the unit. It also has an external antenna connector under a waterproof rubber flap, which enables an external GPS antenna to be connected to it for more accuracy (although this will drain the batteries faster). The only downside I find with the GPS60 is that it is slow to get an initial GPS fix
- Garmin#eTrex - I used a Garmin eTrex for many years from when they first came out. Very rugged, no frills and basic, generally not as well featured as the GPS 60, but for the price, it does everything it needs to.
- Garmin GPSMAP 60CS - absolutely brilliant GPS, which might explain why I had it nicked.
- Youngtech Bluetooth GPS together with a HP iPaq and a Nokia N73 phone - The bluetooth GPS is excellent - using a SIRFStar III chipset, and getting a GPS fix rapidly, but the iPaq that I wanted to use it with has got a Bluetooth Device Manager which kept failing, which made it useless for logging GPS data, and I just didn't find the various software for the Nokia N73 phone to be ideal for the task, but then again, the Nokia N73 is a phone first, and not a GPS unit.
- Apple iPhone 3G - Whilst I've not used the iPhone seriously for mapping, I have found so far, that the iPhone 3G seems to be more accurate than my Garmin GPS 60, both in city and countryside environments.
A few tips (based on practice)
The first thing to do is to clear the track log to have a nice clean set of data to download afterwards.
For logging for OpenStreetMap, I set the GPS 60 to log data at 1 second intervals. I then mark a waypoint at the start of my track, and use the averaging function on the GPS 60 to try and get a more accurate GPS fix to start. The length of time varies, sometimes I'll let it average for around 30 seconds, sometimes it can be 400 to 500 seconds.
Another thing to bear in mind, is that if you don't pull out the GPX data from the Garmin GPS60 whilst it is still an active log, then it discards the time and date information, meaning you can't upload the data to OpenStreetMap.
I usually carry a digital camera around with me when out and about, as I am starting to play with geo tagging my images. Most of the time, I just carry a compact digital camera (a Fuji F610), which I synchronise the time with the GPS.
