I have connected a gps receiver with IMU300Zi ( vis UART) and output from gps is 1 Hz, Protocol-out is UBX and messages out is only NAV-PVT. I have flased INS app ( VS code) using st-link and have used same configuration for ublox receiver as mentioned at https://navview.blob.core.windows.net/web-resources/Instructions to run INS app on OpenIMU300ZI with GNSS.pdf?_t=1592504841811 .
I get gps data and I can see it on Acienna navigation studio but because INS app's default rate is 50 hz and GPS rate is 1 Hz, I can see a lots of spikes because of this issue ( you can see in the below photo)
Can someone help me how can I get smoother/filtered data ?
What I want to achieve is a smother curve something similar to marked in red colour below( or filtered values for Latitude, lon and other parameters) 
What can it be:
Is it a timing issue between IMU and GPS module ? (I have already connected IMU and GPS by 1PPS pin and I receive a pulse every second on IMU. )