Observation RINEX ================= When analyzing Observation RINEX, one plot per encountered observations is generated. Receiver clock offsets are plotted if they were identified. Let's analyze Observations for 4 vehicles: ```bash rinex-cli \ --fp test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz \ -P R01,R08,G21,G31 ``` The received signal power analysis for example, extracted from the analysis report

It is rapidly necessary to determine which vehicles can be encountered in a file. For this reason, we developped the `--sv-epoch` analysis, which helps determine which vehicle to focus on. ```bash rinex-cli \ --fp test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz \ -P G02,R02,R01,G01 --sv-epoch ``` With the Sv per Epoch analysis, you know R01,R02 were both seen at 21:00UTC

When dealing with Observation RINEX, the following operations are most useful: - `--sv-epoch`: vehicle(s) accross epochs identification - `--observables`: observables identification - `-P [DATETIME] [DATETIME]`: time windowing - `-P decim:X `: reduce data quantity - `-P decim:X:Y `: reduce data quantity for given observable, for example Y="l1c" - `-R`, `-G`, `-C`, `-J`, `-E`, `-S`: quickly get rid of given GNSS constellation - `-P GPS,GAL`: focus on constellation(s) you're interested in - `-P G01,E31..`: focus on vehicle(s) you're interested in - `-P L1P,L2P`: focus on specific observables - `-P smooth:hatch:c1c,c2w` : smooth pseudo range observations, on C1C and C2W signals specifically, in this example Phase observations ================== Phase observations are "harder" to handle due to the carrier cycle ambiguities, but also the most interesting data to the advanced user. When phase observations are plotted, we always align them to the origin, for easy phase variations comparison. We also emphasize _possible_ cycle slips when plotting with a black symbol. For example L5 of G10 in `GRAS00FRA_R_2022` is affected:

4 micro (1 tick long) possible corruptions over this channel, which was used to sample L5 at high rate. Cycle slips may happen randomly, for a given channel and signal. To learn more about cycle slips, refer to the [processing section](processing.md). Enhanced Observation analysis ============================= Enhanced Observation analysis is possible as long as Navigation Data is integrated to the context. The enhanced visualization depicts the Sv elevation angles accross encountered epochs, along previous Observations. We do not apply interpolation for Observation / Navigation frames to match in time, we simply exhibit shared epochs. We can take advantage of the `--sv-epoch` opmode, which is designed in case of `--nav` enhanced mode of operation, to depict epochs were both Ephemeris and Observations are shared. In this example, we run it for all GPS vehicles: ```bash rinex-cli \ -f test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz \ -f test_resources/NAV/V3/ESBC00DNK_R_20201770000_01D_MN.rnx.gz \ -P GPS --sv-epoch ``` From the resuling "sv.png" product:

Triangles mark ephemeris frames (low rate) and circles mark observations (high rate). G25, G29, G31 and G12 in 20% to 35% portion of that day, have enough elevation angle information for the enhancement to be interesting. Let's plot it: ```bash rinex-cli \ -f test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz \ -f test_resources/NAV/V3/ESBC00DNK_R_20201770000_01D_MN.rnx.gz \ -P G25,G29,G31,G12 ">=2020-06-25T05:00:00 UTC" "<=2020-06-25T10:00:00 UTC" ```