diff --git a/README.md b/README.md index f317bcc..e2a0372 100644 --- a/README.md +++ b/README.md @@ -27,9 +27,9 @@ It will often be combined with other extensions that describe the actual data, s | sat:orbit_state | string | The state of the orbit. Either `ascending` or `descending` for polar orbiting satellites, or `geostationary` for geosynchronous satellites | | sat:absolute_orbit | integer | The absolute orbit number at the time of acquisition. | | sat:relative_orbit | integer | The relative orbit number at the time of acquisition. | -| sat:anx_datetime | string | The [Ascending Node](https://en.wikipedia.org/wiki/Orbital_node) Crossing (ANX) time, in UTC. It is formatted according to [RFC 3339, section 5.6](https://tools.ietf.org/html/rfc3339#section-5.6). | | sat:orbit_cycle | integer | The number of repeat cycle done by the satellite at the time of the acquisition. [Repeat cycle](https://ltb.itc.utwente.nl/page/498/concept/81577) is the time between two successive identical orbits. | -| sat:orbit_state_vectors | Map | The state vectors of the satellite at the time of acquisition. | +| sat:orbit_state_vectors | Map | The state vectors of the satellite at the time of acquisition. | +| sat:anx_datetime | string | The [Ascending Node](https://en.wikipedia.org/wiki/Orbital_node) Crossing (ANX) time, in UTC. It is formatted according to [RFC 3339, section 5.6](https://tools.ietf.org/html/rfc3339#section-5.6). | *At least one of the fields must be specified.*