WAMO Viewer

ADES

Astrometry Data Exchange Standard. Describes how information can be formatted to allow position and brightness information of an astronomical object to be stored in for instance, a simple text file. Supersedes and is more flexible than the previous format used by the Minor Planet Center, known as the 80-column MPC1992 format. See the MPC's July 2018 ADES announcement and their ADES Data submission page, together with the Concise Description of the ADES standard document.

Base-62

Base-62 is used by the MPC to encode numbers, reducing the amount of characters required to store information.

Base-62 encoded text consists of numbers 0-9 and characters A-Z and a-z only, i.e. the characters "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", to represent "digits" 0 through 61. For example, Base-62 "007C" equals decimal 446 (since "007C" = 0*62*62*62 + 0*62*62 + 7*62 + 12 = 446).

MPC

The Minor Planet Center (MPC) is the single worldwide location for receipt and distribution of positional measurements of minor planets, comets and outer irregular natural satellites of the major planets.

See https://minorplanetcenter.net/about.

MPC1992

A format for storing astrometry data, defined by the Minor Planet Center in 1992 and still in use today, though gradually being replaced by the ADES format. Individual lines are limited to a length of 80 characters.

MPEC

Minor Planet Center Electronic Circular. See https://minorplanetcenter.net/iau/services/MPCServices.html and  https://minorplanetcenter.net/mpec/RecentMPECs.html

ObsID or Observation ID

A block of text, 25 characters long, generated by the MPC when astrometry observations are submitted to them. An ObsID is one of the primary inputs supported by the MPC's WAMO service.

An ObsID contains various sub-fields, all are base-62 encoded, start and end positions being:

1-3=Submission Date (related to the number of days since 1800)

4-6=Submission Seconds since 0h UTC 

7-8=Submission Milliseconds 0-999

9-16=Counter that increases for each submission

17-18=Sub-batch number within the main batch, usually = 1

19-25=Counter for the observation number within the sub-batch

The Date, Seconds and Milliseconds in positions 1-8 are reconstructed from the decoded base-62 values in an ObsID as described by Bill Gray here: https://www.projectpluto.com/temp/mpc_time.c

and summarised as: 

   Digits 1-3 are the base-62 representation of a number calculated from the year, month and day of submission, using:

number = (year - 1800) * 12 * 31 + (month - 1) * 31 + (day-1)

   Digits 4-6 are the base-62 representation of the number of seconds since 00:00:00 UTC

Digits 7-8 = milliseconds in base-62

An example Observation ID is La01fB000000F0yM010000001.

Submission ID

A block of text, 32 characters long, generated by the MPC when astrometry observations are submitted to them. A Submission ID is one of the primary inputs supported by the MPC's WAMO service.

A Submission ID contains various sub-fields, some are base-62 encoded, start and end positions being:

1-23=Submission Date in ISO8601 format (yyyy-mm-ddThh:mm:ss.sss)

24-24=Underscore character "_"

25-32=Submission number (base-62 encoded)

An example Submission ID is 2025-01-26T00:52:06.972_0000Gayu.

Submission Block ID

A block of text, 35 characters long, generated by the MPC when astrometry observations are submitted to them. A Submission Block ID is one of the primary inputs supported by the MPC's WAMO service.

A Submission Block ID contains various sub-fields, some are base-62 encoded. The first 32 characters have the same format as a Submission ID. Start and end positions are:

1-23=Submission Date in ISO8601 format (yyyy-mm-ddThh:mm:ss.sss)

24-24=Underscore character "_"

25-32=Submission number (base-62 encoded)

33-33=Underscore character "_"

34-35=Submission sub-batch number (base-62 encoded)

An example Submission Block ID is:

2025-01-26T00:52:06.972_0000Gayu_01.

WAMO

An acronym used by the Minor Planet Center for their 'Where Are My Observations?' service. See https://minorplanetcenter.net/wamo/.