From 1a00f62fb318dd13059a121fee1b4596e7d6cfe0 Mon Sep 17 00:00:00 2001
From: Nathan <95725385+treefern@users.noreply.github.com>
Date: Fri, 17 Jan 2025 06:53:41 +0000
Subject: [PATCH] NPI-3688 Fix field size and padding in gen_sp3_header() to
make the first header line specification compliant. Update SP3 test data to
match the SP3d spec regarding alignment of the Data Used field.
---
gnssanalysis/gn_io/sp3.py | 36 +++++++++++++++++++++-------
tests/test_datasets/sp3_test_data.py | 8 +++++--
2 files changed, 34 insertions(+), 10 deletions(-)
diff --git a/gnssanalysis/gn_io/sp3.py b/gnssanalysis/gn_io/sp3.py
index b7ee131..0b481b9 100644
--- a/gnssanalysis/gn_io/sp3.py
+++ b/gnssanalysis/gn_io/sp3.py
@@ -935,14 +935,34 @@ def gen_sp3_header(sp3_df: _pd.DataFrame, output_comments: bool = False, strict_
# need to update DATETIME outside before writing
line1 = [
- f"#{head.VERSION}" # E.g. '#d'
- + f"{head.PV_FLAG}" # E.g. 'P' or 'V'
- + f"{_gn_datetime.j20002rnxdt(sp3_j2000_begin)[0][3:-1]}" # E.g. '2024 7 19 0 0 0.00000000' # TODO check. Was indexed with [3:-2] before
- + f"{sp3_j2000.shape[0]:>8}" # Number of epochs E.g. '2'. TODO check what appropriate padding is. Was set to >9
- + f"{head.DATA_USED:>4}" # E.g. 'd+D' ? # TODO confirm intended padding. Was >6
- + f"{head.COORD_SYS:>8}" # E.g. 'IGS20' # TODO check. Was padded as >6
- + f"{head.ORB_TYPE:>4}" # E.g. 'FIT'
- + f"{head.AC:>5}\n" # E.g. 'GAA' or 'AIUB', etc.
+ f"#{head.VERSION}" # Col 1-2: Version symbol, A2. E.g. '#d'
+ + f"{head.PV_FLAG}" # Col 3: Pos or Vel flag, A1. E.g. 'P' or 'V'
+ # Covers col 4-31 (start time in: year, month, day of month, hour, minute, second), various formats.
+ # Widths are: 4, 2, 2, 2, 2, f11.8 (8 digits after decimal point)
+ # Combined output E.g. '2024 7 19 0 0 0.00000000'
+ + f"{_gn_datetime.j20002rnxdt(sp3_j2000_begin)[0][3:-1]}"
+ + " " # Col 32: Unused / space
+ + f"{sp3_j2000.shape[0]:>7}" # Col 33-39: Num epochs, I7. E.g '_____96'
+ + " " # Col 40
+ # Col 41-45: Data used, A5. E.g. 'ORBIT' or '__u+U', etc.
+ # SP3d spec page 14 says:
+ # - 'The data used descriptor was included for ease in distinguishing between multiple orbital solutions
+ # from a single organization.'
+ # - 'A possible convention is given below; this is not considered final and suggestions are welcome.'
+ # - 'Combinations such as "__u+U" seem reasonable.'
+ # Given this, we infer that left padding i.e. right alignment is expected, but that this might not be strict.
+ # CODE (EU) appears to use left alignment e.g. 'd+D '.
+ + f"{head.DATA_USED:>5}"
+ + " " # Col 46
+ + f"{head.COORD_SYS:>5}" # Col 47-51: Coordinate Sys, A5. E.g. 'WGS84' or 'IGS20'(?)
+ + " " # Col 52
+ + f"{head.ORB_TYPE:>3}" # Col 53-55: Orbit Type, A3. E.g. 'BCT' 'FIT'(?), etc. TODO what is BCT? Is that a valid type?
+ + " " # Col 56
+ + f"{head.AC:>4}" # Col 57-60: Agency, A4. E.g. 'MGEX', 'GAA', 'AIUB', etc.
+ + "\n"
+ # We add a newline here because currently all header content has trailing newlines, rather than being stored
+ # without them, and having them added at the end when joining together and outputting as one string.
+ # TODO that might be a nicer approach.
]
gpsweek, gpssec = _gn_datetime.datetime2gpsweeksec(sp3_j2000_begin)
diff --git a/tests/test_datasets/sp3_test_data.py b/tests/test_datasets/sp3_test_data.py
index 04629b4..0487f80 100644
--- a/tests/test_datasets/sp3_test_data.py
+++ b/tests/test_datasets/sp3_test_data.py
@@ -248,8 +248,12 @@
EOF
"""
-# For testing gen_sp3_header()
-sp3_test_data_short_cod_final_header = """#dP2024 7 19 0 0 0.00000000 2 d+D IGS20 FIT AIUB
+# Separate header and content versions of the above.
+# For testing gen_sp3_header():
+# NOTE: CODE (EU) appears to output their 'data used' value with right padding 'd+D ' rather than left padding ' d+D'.
+# Left pad seems to be suggested for 'data used' by SP3d spec, though rules for this column in general seem less strict.
+# Therefore for the purpose of testing our header generator, this example has been *modified* to left pad 'data used'.
+sp3_test_data_short_cod_final_header = """#dP2024 7 19 0 0 0.00000000 2 d+D IGS20 FIT AIUB
## 2323 432000.00000000 300.00000000 60510 0.0000000000000
+ 3 G01G02G03 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0