See How many GPS channels make sense?

That long answer details how adding more channels to a reciever (at additional cost) can:

• Speeds up satellite acquisition
• Reduces power consumption
• Reduces likelihood of losing a 3D fix even in urban canyons
• Provide better sensitivity, allowing fixes in dense forests, and even in some tunnels
• Provides better positioning accuracy

Edit: channels are one factor. A big factor seems to be the fiber-optic gyros in those other units; those are something I can't even find pricing for on the internet. But really I suspect a lot of the costs for the professional kit are non-recurring expense (NRE) of various sorts. More complex software, especially for sensor fusion. Proprietary position-enhancement techniques. Certification and compliance (I see "export compliance" on one of those feature lists, maybe there's a legal cost associated with that?)

High NRE divided across small number of units sold = very high unit cost for seemingly modest performance improvements. Not unusual when dealing with lab or test equipment.

See How many GPS channels make sense?

That long answer details how adding more channels to a reciever (at additional cost) can:

• Speeds up satellite acquisition
• Reduces power consumption
• Reduces likelihood of losing a 3D fix even in urban canyons
• Provide better sensitivity, allowing fixes in dense forests, and even in some tunnels
• Provides better positioning accuracy

Edit: channels are one factor. A big factor seems to be the fiber-optic gyros in those other units; those are something I can't even find pricing for on the internet. But really I suspect a lot of the costs for the professional kit are non-recurring expense (NRE) of various sorts. More complex software, especially for sensor fusion. Proprietary position-enhancement techniques. Certification and compliance (I see "export compliance" on one of those feature lists, maybe there's a legal cost associated with that?)

High NRE divided across small number of units sold = very high unit cost for seemingly modest performance improvements. Not unusual when dealing with lab or test equipment.

See How many GPS channels make sense?

That long answer details how adding more channels to a reciever (at additional cost) can:

• Speeds up satellite acquisition
• Reduces power consumption
• Reduces likelihood of losing a 3D fix even in urban canyons
• Provide better sensitivity, allowing fixes in dense forests, and even in some tunnels
• Provides better positioning accuracy

See How many GPS channels make sense?

That long answer details how adding more channels to a reciever (at additional cost) can:

• Speeds up satellite acquisition
• Reduces power consumption
• Reduces likelihood of losing a 3D fix even in urban canyons
• Provide better sensitivity, allowing fixes in dense forests, and even in some tunnels
• Provides better positioning accuracy

Edit: channels are one factor. A big factor seems to be the fiber-optic gyros in those other units; those are something I can't even find pricing for on the internet. But really I suspect a lot of the costs for the professional kit are non-recurring expense (NRE) of various sorts. More complex software, especially for sensor fusion. Proprietary position-enhancement techniques. Certification and compliance (I see "export compliance" on one of those feature lists, maybe there's a legal cost associated with that?)

High NRE divided across small number of units sold = very high unit cost for seemingly modest performance improvements. Not unusual when dealing with lab or test equipment.