Q: Is there any type of detection device that will detect GPS signals or GPS equipment
A: There is no detector for “GPS” signals. You can use RF detectors if you have a live/real-time tracker as it emits cell phone transmission. But remember the signals can be set too many different intervals the RF detector would only pick up when the unit sends the data signal. You can use a bug detector for and RF signal.
TIP: this would not work on a data logger/passive tracker