I have a clue of where I am

It is a bold statement to make, but I will make it - I have a clue of where I am - thanks to the iBlue 747A+

The quest for a GPS solution started last year when I was to upgrade my cell phone. With many handsets offering an intgrated GPS receiver, the idea of having all I need to geotag my photos always in my pocket seemed too easy and tempting. For most part it was easy. So I landed my hands on the HTC Diamond which was into its launch week back then. The phone is awesome - more so since I don't like Nokia (for reasons that only apply to me) and resist Apple (iPhone 3G was going to hit the shelves in a few weeks). It gave me all I needed in a phone, including a GPS unit to save my tracks and geotag

Well, and then the honeymoon ended (isn't it that way, always). Slowly I started to see why cellphone GPS would not cut it for me. The fact of the matter is that it did not cut it at all, the evidence being that hardly any of my pictures have been geotagged in the last year. Here is what went wrong:

• The sensitivity issue: I knew this. I accepted it thinking that I would sail through. HTC uses the Qualcomm gpsOne chipset (many phone's do so). While it is a good chipset (for reasons I will not cover here), but it is not so signal sensitive. It lacks accuracy. It is reasonably quick to get a FIX (compared to other phones), but not quick enough to blow off my hat. The worst practical scenario is that it works only when you are in open sky or right next to a window (with phone facing the sky).

• The curse of compactness: The famous SiRFstarIII chipset is much better (and is used in some very good dedicated GPS units), but even that is not good enough when used in a phone - the main issue being the size of GPS antenna. The cramped up GPS units - inside the already compact and multifunction devices that today's cellphones are - don't leave enough room for a decent sized antenna to use the signal at its best. There is plenty of detailed information available regarding this

• The power equation: By a far margin, this was the biggest reason why the phone solution did not work for me. None of the phones would have enough battery power to let the GPS unit running all day and logging data points, such that the only thing that you would worry about at the end of the day is to download the track and geaotag the day's worth of pictures. The HTC Diamond, already a über-compact unit with just 900mAh of battery juice would barely last for a few hours if I kept it's bright touchscreen display off (and I am not even complaining about how hot it would get). Even the larger phones with larger batteries would last a few more hours, but still fall short of the all day peace of mind. It seemed I had to constantly look at the phone for battery usage (thereby draining more of it) and signal level. The GPS was somewhat at the expense of the phone functionality. Keeping spare batteries is easy, but not convenient. It is much more convenient to keep a separate GPS DataLogger

Did I say a GPS DataLogger? Yes I did. And that is what the iBlue 747A+ is. You switch it on, some lights blink, you know it got a satellite FIX and then you forget about it while it keeps logging GPS data points all day till you switch it off or it runs out of battery. These units are cheap compared to dedicated GPS navigators because they don't have a fancy screen (or display of any sorts except blinking colored lights) or controls. You control them (change settings) by connecting it to a PC (or phone, if the unit is bluetooth enabled). Similarly you can download recorded data via USB or bluetooth

So I chose to gift myself the iBlue this new year. The new 747A+ model is just launched and is not yet available in Hong Kong, so I ordered from Semsons in USA. The unit arrived in 4-5 days, just before Christmas, to give me a chance to try it for my holiday shooting. I must say I am happy so far (and every picture I have taken since has been geotagged) :-)

To cut it short, I will list out the main points for the iBlue 747A+:

• Uses the MTK v2 chipset which has an excellent -165dBm sensitivity. I have found it to maintain the FIX pretty well indoors (a rare feat for most loggers).
  

• The acquisition time is very fast, in the range of 30-45 sec. Reacquisition is same, but the unit is also the first data logger to provide AGPS support. With properly updated ephemeris data, the TTF (time to fix) is as low as 15-20 sec. The supplied application lets you download and update AGPS data
  

• Dual interface with USB and bluetooth support. When connected to a PC or phone, it can also function as a GPS mouse (means that you can get live GPS data that an application can plot and use for navigation). I use gpsVP on my HTC Diamond for navigation and mapping (google maps work fine too, but has no cached mode and uses my data connection). Charges via USB or supplied car charger
  

• Dual mode. In navigation mode, it can connect to a device via bluetooth and supply real time GPS data. In log mode it will simply log tracks to internal memory
  

• Battery life of 32 hours (this is where the MTK chipset shines). Uses a Li-ion battery. The good part is that the battery is the one found in lower end Nokia phones, so easy to find and replace if there ever be a need
  

• Can log 125,000 data points. If logging at one point every second (my default configuration), this will get you nearly 35 hours of logging. Logging interval can be changed via PC / phone. factory default is every 5 sec, but I have changed it to 1Hz

• Compatible with the fabulous BT747 application. BT747 is as good as it gets to controlling MTK devices. It also lets me download tracks and convert them to various formats (NMEA, gpx, kml, kmz, csv, html etc)

The unit is fairly compact to sit in my pocket all day. Here is a size illustration


Here is my HTC diamond connected to the iBlue. gpsVP in monitors mode showing all the data in real time. Don't forget that these pictures were done indoors in my apartment, and I still have a satellite fix

A full gallery containing more pictures is here

Finally, here is some end result. A track captured on 29th Dec. I took a ferry to Central and spent the day there indoors, then a ferry across the harbor to TST. Spent some time around, and then took the train to TST. The red line indicates no signal (the train was underground). Finally took a bus back to the starting point. 12 hours worth of logging without even looking at the device once.

And before anyone asks, here is the geotagging alteration to my image ingestion workflow. I shoot RAW and as part of ingestion, convert my originals to DNG format. Once I have the DNG files ready, I do the rating and get rid of any images that I do not want to keep. Next is keywording. This is where I inserted geotagging in my workflow.

I load the track file from my iBlue using BT747. I have set it to download one track file per day so that I do not need to organize any further. I convert the tracklog to gpx format. Now I use GeoSetter (IMO, the best tagging app for windows users, and it's free too) for actual tagging. All I need to give it is the tracklog file and the folder containing my images; and a few minutes to do its thing. As an added bonus, GeoSetter can also fill in the IPTC location/city/country tags based on track location

Before you do that, don't forget to keep the camera clock in sync with GPS clock :-)