Tracking L2C on OEMV-2 and OEMV-3

The L2C code is only available on OEMV-2 and OEMV-3 receivers. A benefit of choosing to track the L2C code is the ability to track extremely weak L2 signals. L2C is just 2.3 dB weaker than L1 C/A code. Compared to codeless and semi-codeless techniques, L2 tracking with L2C is slightly improved. [OEMV Firmware Reference] To enable the L2C tracking, there is a command called FORCEGPSL2CODE which allows user to force the receiver to track L2P(Y), L2C or AUTO. AUTO will uses the best L2 code type available. It will try L2C first and switch to L2P(Y) if L2C is not available. It is preferable to use L2P(Y) until more satellites with L2C are launched. Currently, the OEMV-2 and OEMV-3 default to L2P(Y) tracking. It is uncertain what will happen in all positioning cases if the base and rover consist of mixed hardware (i.e. base has an OEM4 tracking only L2P(Y) and rover has an OEMV tracking L2C). This will all be sorted out as more L2C satellites are available. In the RANGE log, the Channel Tracking Status contains the field of signal type used in the measurement. For example: GPS: 0 = L1 C/A 5 = L2P 9 = L2P codeless 17 = L2C For detail information, please refer the OEMV Firmware Reference Manual. http://www.novatel.com/Documents/Manuals/om-20000094.pdf