OpNav Tracking File Format
The OpNav tracking data format is a comma-separated format containing observation records. A version indictor is also required as the first uncommented line of the file. Version 1.1 is the current version. Comment lines can occur anywhere in the file and are identified by placing # as the first character in the line.
Data records contain a fixed number and order of fields, but some fields may be empty if the associated data is not available.
The following table delineates the OpNav tracking file header field names and their descriptions, and includes whether or not each field is required.
| Field Name | Description | Required? |
|---|---|---|
| Year | Year as a four-digit integer | Y |
| Month | Month as a two-digit integer | Y |
| Day | Day of month as a two-digit integer | Y |
| Hour | Hour of day as a two-digit integer | Y |
| Minute | Minute of hour as a two-digit integer | Y |
| Seconds | Seconds past the minute as a real value | Y |
| Camera ID | Tracking ID of the tracking instrument representing the OpNav camera | Y |
| Target Body | Textual name of the target body (e.g., Moon) | Y |
| Meas Type | Type of OpNav measurement processing {Point | Limb | LMark} | Y |
| Landmark ID | Integer or textual identifier of landmark from Landmark File; required when Meas Type is LMark | N |
| Reference Frame | Inertial reference frame used to represent bearing measurements; recommend {ICRF | MEME J2000}; also valid {MEME of Date, TETE of Date, TEME of Date} | Y |
| Right Ascension | Apparent right ascension of landmark centroid in degrees; -180 <= Value <= 360.0 | N |
| Declination | Apparent declination of landmark centroid in degrees; -180 <= Value <= 360.0 | N |
| Range | Range to centroid of target body, in meters; only valid when Meas Type is Limb | N |
| Right Ascension Sigma | Uncertainty of right ascension in degrees; value > 0 | N |
| Declination Sigma | Uncertainty of declination in degrees; value > 0 | N |
| Range Sigma | Uncertainty of range in meters; value > 0 | N |
Here is an example of an OpNav tracking file:
Version 1.1
# Notes regarding Optical Navigation measurements:
# * [Type {Point|Limb|LMark}] differentiates between Point-Based, Limb-Based, and Landmark-Based observations.
# * [LandmarkID] is the integer ID or textual name for landmark found in landmark data file. It's blank for non-landmark measurements.
# * [Reference Frame {ICRF | MEME J2000 | ...}] are for RA and Dec measurements.
# * [RA], [Dec], and [Range] values are blank if not produced for a particular time step.
# * [RA] and [Dec] are measured in degrees.
# * [Range] is measured in meters.
# * Std Dev values represent White Noise Sigma values for each measurement.
# * Std Dev values use the same units as their corresponding measurement.
#
# Yr , Mon , Day , Hr , Min , Secs , TI ID , Target , Type , Landmark , Frame , RA , Dec , Rng , RA Std Dev, Dec Std Dev, Rng Std Dev
2021,07,01,12,00,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,173.2491,1.7138,,0.00167,0.00167,
2021,07,01,12,01,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,173.7503,1.4412,,0.00167,0.00167,
2021,07,01,12,02,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,174.2519,1.1680,,0.00167,0.00167,
2021,07,01,12,03,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,174.7541,0.8943,,0.00167,0.00167,
2021,07,01,12,04,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,175.2568,0.6199,,0.00167,0.00167,
2021,07,01,12,05,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,175.7601,0.3450,,0.00167,0.00167,
2021,07,01,12,06,0.00,1001,Sun.Earth.Moon,LMark,00-1-000008,ICRF,176.2640,0.0696,,0.00167,0.00167,
2021,07,01,12,07,0.00,1001,Sun.Earth.Moon,LMark,02-1-001799,ICRF,178.6649,2.6358,,0.00167,0.00167,
2021,07,01,12,08,0.00,1001,Sun.Earth.Moon,LMark,02-1-001799,ICRF,179.1735,2.3613,,0.00167,0.00167,
2021,07,01,12,09,0.00,1001,Sun.Earth.Moon,LMark,02-1-001799,ICRF,179.6825,2.0865,,0.00167,0.00167,
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