These new dGPS units seem to be accurate to around 2cm as shown in our test. This is for a close baseline (and at the moment doesn’t use GLONASS).
This is a GPS tracker we quickly built as a test of tracking icebergs – it uses Satellite (Iridium) short text messages to send its location to us every 12hrs. Inside is a large lithium battery pack. The photo below shows a water test in the sink – just in case it ends up in the sea. We used a unit from YB Tracking. More info later!
Just added a new page collecting together most of the 4x4s we have used in Iceland
We have been analysing the time-lapse image sequences from the river camera. Mostly it recorded at 4-hour intervals, but for a couple of days in September 2012 it took pictures every minute – the sequence is shown here.
At about noon the river rises by a few centimetres. The change is hardly noticeable, but we can measure the level quite accurately with careful image analysis, and we can see it happening by watching the river start flowing over a rock in this video.
We would like to relate this to what is happening up on the glacier. One factor is when the sun falls on the ice, and we can work this out from a map of the terrain. Here we are using a digital elevation model from the ASTER instrument aboard the Terra satellite. (ASTER GDEM is a product of METI and NASA.) The animation shows sunlit areas on the glacier and surrounding mountains increasing as the sun rises on 25 September 2012.
We are occasionally getting pictures from the camera set up on the moraine of the glacier.