[time-nuts] GPS-SDR-SIM

[jimlux]

On 3/27/19 11:49 AM, coderman via time-nuts wrote:

Compiled the software, but...

> he user specifies the GPS satellite constellation through a GPS broadcast ephemeris file. The daily GPS broadcast ephemeris file (brdc) is a merge of the individual site navigation files into one. The archive for the daily file is:
> 
> ftp://cddis.gsfc.nasa.gov/gnss/data/daily/

There's a ton of files under that.. broken down by year/day of year/ and 
then some subdirectories with dozens of files, that appear to be RINEX 
(the names are things like
 
ftp://cddis.gsfc.nasa.gov/gnss/data/daily/2019/088/19f/USN700USA_R_20190880000_01D_CN.rnx.gz

A casual browse did not find the brdc.


Here's the toplevel readme  - there's quite a few subdirectories in the 
archive that are not listed in the readme. suffix letters, g,h,i,k,l, etc.

**********************************************************************
                    Welcome to the CDDIS GPS Archive

   The main directories are:

  /campaign                   GPS data from selected campaigns

  /daily/YYYY/DDD/YYd         Observation files for year YYYY and day DDD
                              (Hatanaka format)
                  /YYm        Met files for year YYYY and day DDD
                  /YYn        Navigation files for year YYYY and day DDD
                  /YYo        Observation files for year YYYY and day DDD
                  /YYs        Summary files for year YYYY and day DDD
                              (teqc output)
  /hourly/YYYY/DDD/HH         Hourly RINEX GPS files for year YYYY, day DDD,
                              and hour HH; observation (Hatanaka format),
                              navigation and met data

  /high-rate/YYYY/DDD/YYd/HH  Observation files for day YYDDD and hour HH
                              (Hatanaka format)
                     /YYm/HH  Met files for day YYDDD and hour HH
                     /YYn/HH  Navigation files for day YYDDD and hour HH

  /satellite/SATNAME/YYYY/DDD GPS data from on-board GPS receivers for
                              satellite SATNAME for year YYYY and day DDD

   /gps/products/ionex/YYYY/DDD    Daily IONEX products for year YYYY and
                                   day DDD
                /trop/WWWW         Weekly GPS troposphere products for GPS
                                   week WWWW
                     /YYYY         Yearly GPS troposphere products for year
                                   YYYY
                     /nrt/WWWW     Near real-time GPS troposphere products
                                   for GPS week WWWW
                /trop_cmp/YYYY/DDD Troposphere comparison results for year
                                   YYYY and day DDD
                /trop_new/YYYY/DDD New IGS troposphere product for year
                                   YYYY and day DDD
                /WWWW              Weekly GPS precise orbits, etc. for GPS
                                   week WWWW

  All files are archived in UNIX compressed format.

  Contact Carey Noll (Carey.E.Noll at nasa.gov) for further information.
  **********************************************************************

  The local date and time is: %T