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fixed parse errors #24

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Merged
cprosche merged 1 commit into from
Dec 28, 2024
Merged

fixed parse errors #24

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152 changes: 76 additions & 76 deletions tle.go
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Original file line number Diff line number Diff line change
Expand Up @@ -53,11 +53,7 @@ type TLE struct {
}

// Parses TLE (2LE) and 3LE formats.
// Features:
// - Supports Alpha 5 format
// - Validates the checksums
// - Converts the epoch to a time.Time
// - Converts numbers to correct type
// Features: Supports Alpha 5 format, validates the checksums, converts the epoch to a time.Time, converts numbers to correct type
func Parse(txt string) (TLE, error) {
var (
trimmedTxt = strings.TrimSpace(txt)
Expand All @@ -81,72 +77,10 @@ func Parse(txt string) (TLE, error) {
}

// Parse the NORAD ID from the first line
result.NoradIdStr = result.Line1[2:7]
if _, err := strconv.Atoi(string(result.NoradIdStr[0])); err == nil {
noradInt, err := strconv.Atoi(result.NoradIdStr)
if err != nil {
return TLE{}, err
}
result.NoradId = noradInt
} else {
rest := result.NoradIdStr[1:]
firstChar := result.NoradIdStr[0]
switch firstChar {
case 'A':
result.NoradId, err = strconv.Atoi("10" + rest)
case 'B':
result.NoradId, err = strconv.Atoi("11" + rest)
case 'C':
result.NoradId, err = strconv.Atoi("12" + rest)
case 'D':
result.NoradId, err = strconv.Atoi("13" + rest)
case 'E':
result.NoradId, err = strconv.Atoi("14" + rest)
case 'F':
result.NoradId, err = strconv.Atoi("15" + rest)
case 'G':
result.NoradId, err = strconv.Atoi("16" + rest)
case 'H':
result.NoradId, err = strconv.Atoi("17" + rest)
case 'J':
result.NoradId, err = strconv.Atoi("18" + rest)
case 'K':
result.NoradId, err = strconv.Atoi("19" + rest)
case 'L':
result.NoradId, err = strconv.Atoi("20" + rest)
case 'M':
result.NoradId, err = strconv.Atoi("21" + rest)
case 'N':
result.NoradId, err = strconv.Atoi("22" + rest)
case 'P':
result.NoradId, err = strconv.Atoi("23" + rest)
case 'Q':
result.NoradId, err = strconv.Atoi("24" + rest)
case 'R':
result.NoradId, err = strconv.Atoi("25" + rest)
case 'S':
result.NoradId, err = strconv.Atoi("26" + rest)
case 'T':
result.NoradId, err = strconv.Atoi("27" + rest)
case 'U':
result.NoradId, err = strconv.Atoi("28" + rest)
case 'V':
result.NoradId, err = strconv.Atoi("29" + rest)
case 'W':
result.NoradId, err = strconv.Atoi("30" + rest)
case 'X':
result.NoradId, err = strconv.Atoi("31" + rest)
case 'Y':
result.NoradId, err = strconv.Atoi("32" + rest)
case 'Z':
result.NoradId, err = strconv.Atoi("33" + rest)
default:
return TLE{}, errors.New("invalid NORAD ID Alpha-5 format")
}

if err != nil {
return TLE{}, err
}
result.NoradIdStr = strings.TrimSpace(result.Line1[2:7])
result.NoradId, err = parseNoradId(result.NoradIdStr)
if err != nil {
return TLE{}, err
}

result.Classification = result.Line1[7:8]
Expand Down Expand Up @@ -191,7 +125,7 @@ func Parse(txt string) (TLE, error) {
}

// line 2
secondNoradIdStr := result.Line2[2:7]
secondNoradIdStr := strings.TrimSpace(result.Line2[2:7])
if secondNoradIdStr != result.NoradIdStr {
return TLE{}, errors.New("line 1 and line 2 NORAD IDs do not match")
}
Expand All @@ -217,17 +151,17 @@ func Parse(txt string) (TLE, error) {
return TLE{}, err
}

result.MeanAnomalyDegrees, err = strconv.ParseFloat(result.Line2[43:51], 64)
result.MeanAnomalyDegrees, err = strconv.ParseFloat(strings.TrimSpace(result.Line2[43:51]), 64)
if err != nil {
return TLE{}, err
}

result.MeanMotion, err = strconv.ParseFloat(result.Line2[52:63], 64)
result.MeanMotion, err = strconv.ParseFloat(strings.TrimSpace(result.Line2[52:63]), 64)
if err != nil {
return TLE{}, err
}

result.EpochRevolutionCount, err = strconv.Atoi(result.Line2[63:68])
result.EpochRevolutionCount, err = strconv.Atoi(strings.TrimSpace(result.Line2[63:68]))
if err != nil {
return TLE{}, err
}
Expand Down Expand Up @@ -269,7 +203,7 @@ func convertYearAndDayToDate(twoDigitYear, day string) (time.Time, error) {
nanosecondsFloat := dayFloat * 24.0 * 60.0 * 60.0 * 1e9
ns := time.Duration(nanosecondsFloat)

// subtract a day the .Date adds a day
// subtract a day because the .Date adds a day
return time.Date(year, 1, 1, 0, 0, 0, 0, time.UTC).Add(ns).Add(-time.Hour * 24), nil
}

Expand Down Expand Up @@ -342,3 +276,69 @@ func parseBStar(bstar string) (float64, error) {

return strconv.ParseFloat(parseableStr, 64)
}

func parseNoradId(s string) (int, error) {
if _, err := strconv.Atoi(string(s[0])); err == nil {
noradInt, err := strconv.Atoi(s)
if err != nil {
return 0, err
}
return noradInt, nil
} else {
rest := s[1:]
firstChar := s[0]
switch firstChar {
// I and O are not used
case 'A':
return strconv.Atoi("10" + rest)
case 'B':
return strconv.Atoi("11" + rest)
case 'C':
return strconv.Atoi("12" + rest)
case 'D':
return strconv.Atoi("13" + rest)
case 'E':
return strconv.Atoi("14" + rest)
case 'F':
return strconv.Atoi("15" + rest)
case 'G':
return strconv.Atoi("16" + rest)
case 'H':
return strconv.Atoi("17" + rest)
case 'J':
return strconv.Atoi("18" + rest)
case 'K':
return strconv.Atoi("19" + rest)
case 'L':
return strconv.Atoi("20" + rest)
case 'M':
return strconv.Atoi("21" + rest)
case 'N':
return strconv.Atoi("22" + rest)
case 'P':
return strconv.Atoi("23" + rest)
case 'Q':
return strconv.Atoi("24" + rest)
case 'R':
return strconv.Atoi("25" + rest)
case 'S':
return strconv.Atoi("26" + rest)
case 'T':
return strconv.Atoi("27" + rest)
case 'U':
return strconv.Atoi("28" + rest)
case 'V':
return strconv.Atoi("29" + rest)
case 'W':
return strconv.Atoi("30" + rest)
case 'X':
return strconv.Atoi("31" + rest)
case 'Y':
return strconv.Atoi("32" + rest)
case 'Z':
return strconv.Atoi("33" + rest)
default:
return 0, errors.New("invalid NORAD ID Alpha-5 format")
}
}
}
22 changes: 22 additions & 0 deletions tle_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -196,6 +196,28 @@ ISS (ZARYA)
assert.Nil(t, err)
assert.Equal(t, localExpected, got)
})

t.Run("Many different TLEs will parse", func(t *testing.T) {
tles := []string{
`ISS (ZARYA)
1 25544U 98067A 20274.51782528 .00000867 00000-0 22813-4 0 9994
2 25544 51.6441 93.0000 0001400 11.0000 349.0000 15.49300070250767`,
`1 58465U 23185D 24363.11104941 .00028654 00000-0 95911-3 0 9999
2 58465 97.4051 67.6717 0007093 330.0760 30.0075 15.30897368 59670`,
`1 33591U 09005A 24363.16300298 .00000451 00000-0 26450-3 0 9992
2 33591 99.0226 60.7854 0014697 104.8667 255.4134 14.13241242819028`,
`1 38771U 12049A 24363.09173364 .00000381 00000-0 19401-3 0 9993
2 38771 98.6040 55.7087 0001839 103.7914 256.3468 14.21393899637091`,
`1 9478U 76101A 24362.62107380 -.00000010 00000-0 00000+0 0 9998
2 9478 6.9318 311.1675 0107070 341.0025 254.4654 0.97590429118242`,
}

for _, raw := range tles {
tle, err := Parse(raw)
assert.Nil(t, err)
assert.NotNil(t, tle)
}
})
}

func TestYearAndDayToDate(t *testing.T) {
Expand Down
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