Satellite Phase Center Offset: Correct satellite PCOs with the selected ANTEX File
Satellite Phase Center Variations: Correct satellite PCVs with the selected ANTEX File
Receiver Phase Center Offset: Correct receiver PCOs with the selected ANTEX File
Receiver Phase Center Variations: Correct receiver PCVs with the selected ANTEX File
Antenna Reference Point Correction: Correct the antenna reference point. Therefore, the antenna offset of the RINEX header is used.
Group Delay Variations: Correct GDVs (e.g., BeiDou)
Phase Wind-Up Correction: Correct Phase Wind-Up [Wu et al., 1993]
Eclipse Condition: If enabled, raPPPid excludes satellites during the processing in the Earth's shadow. Therefore, a simple cylinder model is used. When using an ORBEX file, you might not use this option due to the availability of the satellite attitude.
Solid Tides Correction: Correct solid Earth tides [Petit and Luzum, 2010]
Ocean Loading: Correct for the ocean loading effect, which is only possible for stations having coefficients from http://holt.oso.chalmers.se/loading/index.html in the file OceanLoading.blq (located in the DATA folder, raPPPid/DATA/OceanLoading.blq). Otherwise, no correction for ocean loading correction is applied. To correct for ocean loading, the file 'OceanLoading.blq' in the DATA folder needs to contain the 4-digit station name and the coefficient from http://holt.oso.chalmers.se/loading/. To add a station, go to the mentioned website. Create the coefficients with the following settings: the GOT4.7 model, vertical and horizontal displacements, elastic Green functions, and BLQ format. After you have retrieved the coefficients, add them into 'OceanLoading.blq'. The 4-digit station name in the RINEX file's header and OceanLoading.blq must match. Otherwise, no or wrong coefficients are extracted from the blq-file.
Polar Tides: Correct for the rotational deformation due to polar motion. If enabled, raPPPid downloads the *.erp file corresponding to the selected precise orbit/clock product (e.g., IGS final or CODE MGEX). Currently, this correction can not be applied when manually selecting these satellite products. Please note that the model of the mean pole has to be defined correctly (consistent with the satellite product, variable DEF.ctpm, default = ‘cubic’).
raPPPid automatically checks the satellite orbit file (e.g., sp3) for the coordinate system and tries to apply the corresponding ANTEX file.
Use existing igsXX.atx: Use the version of ANTEX file currently available in \DATA\ANTEX. If igsXX.atx is not available, raPPPid downloads it.
Download current igsXX.atx: Download the newest version of ANTEX file, for example, when the igsXX.atx was updated (check IGSMAIL).
Manual choice: Select the ANTEX file manually (e.g., M20.atx for CODE MGEX PPP-AR)
MyAntex.atx: Add your own PCO and PCV corrections into a file called MyAntex.atx located in raPPPid\DATA\ANTEX. The corrections included in this file (raPPPid\DATA\ANTEX\myAntex.atx) are then used to correct the receiver antenna phase center offsets and variations. raPPPid will check if there are suitable corrections before the processing starts. Make sure that the antenna name in the RINEX file header (ANT # / TYPE) corresponds to the name in myAntex.atx (TYPE / SERIAL NO) and that the formatting is correct (e.g., the antenna name is placed centered in the RINEX header). Note that myAntex.atx is only used for receiver antenna corrections. For the satellite phase center offsets and variations the ANTEX file specified in the GUI is used.
L1-C1 Difference: The difference between the code and phase observation is used to fit a polynomial of 3rd degree. The window size defines the number of epochs that are used. This cycle slip detection method is implemented for single-frequency observations only.
dLi-dLj Difference: The difference between the difference of the phase observation of the current and the last epoch is used for detecting cycle-slips: dLi - dLj = (Li - Li-1) - (Lj - Lj-1) with, for example, i=1 and j=2 (e.g., IF LC is processed). Note that if one phase observation is missing (e.g., L2), a cycle slip is flagged for L1 and L2. Furthermore, the threshold should be chosen considering the observation interval to achieve optimal results, for example:
| interval [s] | threshold [m] |
| 0 - 1 | 0.05 |
| 1 - 20 | 0.005 intv + 0.05 |
| 20 - 60 | 0.15 |
| 60 - 100 | 0.25 |
| 100 < | 0.35 |
Doppler Shift: Doppler observations are used to predict the phase observation of the current epoch. If the difference between the predicted and actual phase observations is too big, a cycle-slip is detected. The formula used for prediction: Lpred = Lold + dt sqrt(Dnow Dold). Please note that this approach requires a high observation interval (e.g., 1s).
Time difference: Only the first processed frequency is checked. Use, for example, dLi-dLi difference for 2+ frequencies. Depending on the specified degree (e.g., 3), the phase observations of the last (e.g., three) epochs are differenced. If this (e.g., triple) difference exceeds the defined threshold, a cycle slip is flagged. Please note that this approach is only sensible for high-rate observations (e.g., 1s observation interval) and static or very slow-moving receivers.
Use LLI of RINEX-File: If this checkbox is enabled, raPPPid excludes phase observations where the Loss of Lock Index (LLI bit) is set in the RINEX observation file. Check the RINEX specifications for more details.
Code difference: Only for single frequency processing and similar to the cycle slip detection method "Time Difference". Depending on the specified degree (e.g., 3), the code observations of the last (e.g., three) epochs are differenced. If this (e.g., triple) difference exceeds the defined threshold, the satellite is set under the cutoff angle. Note that the median of the (e.g., triple) difference is subtracted because low-cost data may have “jumps” or some kind of noncontinuous code observations (e.g., smartphone data). Additionally, a cooldown can be used: the satellite will not be used for the next, for example, 600 seconds. Please note that this multipath detection approach is only sensible for high-rate observations (e.g., 1s observation interval).
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