
APN-039 Rev 2 December 7, 2007
2
Test Results
This section describes investigation testing performed on the OEMV family of receivers in Pass-to-Pass
mode with 3.100 software. These tests were done on a rooftop in a static environment. Data was
collected for 24 hours, then post-processed for various pass time intervals. All of the data was collected
with the following command filter settings:
PASSTOPASS enable on on default 1.0.
Data processing starts by computing the cross-track error, relative to a N-S line for each point, in the data
set. For the 15 minute time interval, the RMS (root mean square) cross-track error is calculated using
each of the 900 points in one pass. The same thing is done for the second pass and so on. Once this is
caluculated, there is a single value that can be used to represent each pass in the field. To evaluate how
much variability there is between passes, the single value from each pass is differenced with the previous
pass. The overall pass to pass error is calculated as the mean of the absolute value of these differences.
The test results reveal how much the horizontal position changes over the short time interval, not how
much it changes over the entire data set. All the results in Table 1 and Table 2 are for the horizontal
RMS. The
se results are from using a 15 minute pass interval in post-processing.
Table 1 contains results from tests with an OEMV with L1 only and P
ass to Pass smoothing enabled.
Table 1: OEMV with L1
Test Number of Passes Pass to Pass RMS
Accuracy (m)
WAAS L1 only 95 0.14
CDGPS L1 only 95 0.14
OmniSTAR VBS 95 0.13
Table 2 contains the results from tests with an OEMV3 with L1 and L2 and Pass to Pass smoothing
enabl
ed.
Table 2: OEMV3 with L1 & L2
Test Number of Passes Pass to Pass RMS
Accuracy (m)
WAAS L1/L2 95 0.12
DGPS 95 0.16
RTK 95 0.015
CDGPS L1/L2 95 0.13
OmniSTAR VBS 95 0.1
OmniSTAR HP 95 0.03
OmniSTAR XP 95 0.03
Pass to Pass Command
This command is available on all OEMV-based products with 3.100 firmware or higher.
Command: PASSTOPASSMODE
PASSTOPASSMODE Enable/disable solution smoothing modes
This command allows you to enable or disable different solution smoothing modes. The command filters
include the following:
Command Filters: