GPS Receiver GP-1
DISCONTINUED PRODUCT REPLACED BY GP-3 RECEIVER
GP-1 – Mobile GNSS (GPS + Glonass) Receiver (SKU#190)
The GP-1 mobile GNSS receiver is designed to receive the signals from two geolocation systems – GPS / Glonass and it can be connected to LunaBat DFR-1 ultrasound bat detector or to our other future devices. Receiving signals from more than one geolocation system significantly increases the number of satellites seen by the device, which can be useful in places with poor sky visibility or poor weather conditions. The continuity of the geolocation is improved, and to a certain extent accelerated the speed and increased accuracy of obtaining the geolocation. The GP-1 receiver is designed mainly to be mounted directly in the expansion slot in the LunaBat DFR-1 detector or to be connected to detector (or other device) via optional extender cable. It works with two geolocation systems simultaneously to keep your location in more severe conditions than if you were using only one system.
When 2D or 3D fix is achieved, it is indicated by a blue blinkin’ LED located above the LCD screen on the detector. The receiver (when connected to detector) can store ephemeris and almanac even after the detector is turned off, and when detector is re-enabled – achieving fix is much faster than at first fix (this is called: Hot Start mode, when under 2 hours, and Warm Start mode for more than 2 hours after turning off the detector).
Why the GNSS instead of GPS only?
When the conditions are good you can get the reception from multiple satellites and obtaining the coordinates is easy on most devices. In the photo on the right side you can see the GP-1 receiver (on the left side, right before embedding it in the shielded enclosure) along with an android phone as a monitoring device (GP-1 is connected to PC via USB-UART interface and mobile phone is connected to PC via TeamViewer application). On the right side of the photo is the Garmin GPSmap 78 device. As you can see – both devices receive strong signals from multiple satellites. On the Garmin device we have usable 9 of 10 signals from GPS satellites, and on the GP-1 receiver we have 9 of 10 GPS signals (dark blue bars) and 6 of 8 Glonass signals (dark red bars). In total, we have 15 of 18 signals with strong, usable levels. To get 2D fix, you need a strong signal from at least three satellites. To get 3D fix, you need a strong signal from at least four satellites, so both devices have more than enough signals for obtaining 3D coordinates.
But the situation changes when the reception conditions are worse. The pictures below shows the same receivers inside the apartment in the building (which corresponds to poorer reception conditions and less visibility of the sky, which is common in the real world of field work). You may notice a smaller number of satellites from which we can get a usable signals, as well as a lower carrier-to-noise ratios (shorter bars). In the photo on the left you can see that Garmin device is using only one geolocation system (american GPS) and it is on the edge of maintaining the coordinates, there is “Weak GPS Signal” alert on the screen, because of the reception of only 3-4 signals from satellites. But our GP-1 receiver still has a signal from both GPS and Glonass satellites, and receives a total of 11 usable signals.
There is also GP-2 – an automotive version of this receiver – more info HERE.
* – compatible equipment has to be capable of receiving and/or transmitting NMEA sentences and/or PMTK protocol with 9600bps base baud rate (it is default rate of the receiver module, which can be changed MTK protocol). Also the supply voltage for the receiver must be within 3.0-3.6V range.
* – default rate, can be changed using PMTK protocol.