We managed to build a very small, lightweight (only 18 grams) GPS GSM transmitter for sousliks or European ground squirrels (Spermophilus citellus). Mostly batteries are the limiting part in the weight of a transmitter. In this case we were fortunately dealing with a diurnal mammal, which made it possible to use small high quality solar cells in combination with a super capacitor and small LiPo battery reducing the weight to an absolute minimum. The photos show our miniature GPS GSM tracker of only 25.2 x 17.2 mm and the lid of the enclosure with the solar panels and a flat, very sensitive, active GPS PCB antenna.
Sousliks
