This function is available in the standard version of OCAD.
Make sure you select the OCAD symbol you wish to use for each waypoint and
its number.
Most modern USB GPS models (e.g. Garmin Colorado, Oregon or Dakota)
store waypoints as a gpx file.
Make sure GPS is attached to your computer as a Mass Storage Unit
Press load next to the GPX option and load the file with the gpx directly
from your GPS unit.
B) Using the Custom Maps function on Garmin USB GPS Units (Colorado,
Oregon or Dakota)
Let's face it carrying your computer around while field working is not a
particularly attractive option! Apart from the extra weight & difficulty
viewing in bright sunlight there is also the risk of serious damage.
Producing a kmz file with OCAD 10 and above: Using custom maps you can have a calibrated version of your map on your GPS
as an aid to keeping track with your position while mapping. To use this feature
you need to produce a kmz file of your maps. There is a compelling case
for having a copy of at least the standard version of OCAD 10 or above as this will
produce these files from any geo-referenced map you have in OCAD. This is simply
loaded into the Custom Maps directory which you will need to make on your GPS.
This needs to be a sub-directory of the Garmin directory. (typed exactly
> CustomMaps with no space )
Producing a kmz file with OCAD and Google Earth: If you don't have
OCAD 10+ a geo-referenced kmz file can be produced using Google Earth. Again
this would not be as spatially accurate as one produced in OCAD based on a
commercial geo-referenced photograph or photogrammetry. Garmin have a
section devoted to Custom
Maps which explains how to do this.
C) Using a smart phone as a GPS with OCAD
Although you cannot run OCAD on a smartphone you can use an OCAD image if you
have at least OCAD 10 standard. Simply export all of part of a geo referenced
OCAD as a tiff file making sure you select "produce world file"
You will then need purchase an App on your phone to manage these files. I
have found Avenza Maps to be
excellent in that respect. Documentation on the web is excellent. This software
will work with IOS and Android phones & tablets. There is also now a beta
Windows version (Jan 2016) available. The big advantage for mapping is that it
gives you access to a very portable high resolution image of your map. This is
not currently achievable on a normal GPS. For example my own GPS (Garmin Oregan
300) is limited to 150dpi. On my iPhone I am using 300 dpi which seems adequate.
Don't throw away your traditional GPS yet. It contains lots of features not
available on a smart phone:
Accuracy levels will tend to be high due to their ability to access up to
12 satellites at once with a potential accuracy of 3m. Smart phones vary
considerably with some (eg iphone 3 or earlier) relying on the triangulation
within the phone network to improve accuracy. Outside of the network area
they may be lucky to achieve 8m accuracy. Newer models have more
sophisticated chips but are still usually limited to 4 satellites.
With the GPS on you are likely to find that your battery will be consumed
rather rapidly! I tend to use mine only as needed and do the serious work
with my normal GPS. My Garmin GPS keeps going all day on re-chargeable
batteries
