8.4.2 Ionospheric Function and Cycle Slips
Dual-frequency observations can eliminate the first-order ionospheric effects by forming the popular dual-frequency ionospheric-free functions. Consider the relevant terms of the ionospheric-free function (6.1.41)
and the ionospheric function (6.1.44)
with 
, 
, and the squared ratio 
as already defined in (6.1.1). Analyzing these dual-frequency carrier phase functions requires extra attention because certain cycle slip combinations on L1 and L2 generate almost identical effects. For example, consider the ionosphere-free phase observable (8.4.24). The ambiguities enter this function not as integers but in the combination of 
, causing noninteger change when cycle slips occur.
Table 8.4.1 lists in columns 1 and 2 small changes in the ambiguities and shows in columns 3 and 4 their effects on the ionospheric-free and the ionospheric phase ...
Get GPS Satellite Surveying, 4th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
