# Kislovodsk Mountain Astronomical Station Data Formats

All formats are plain text. The following functions in `io.py` read these files:

| Format | Contents | Reader |
| --- | --- | --- |
| `.dat` | Coronal intensity as a function of position angle | `open_corona` |
| `.abp` | Object masks in pixel coordinates | `open_abp` |
| `.bp` | Tables of object parameters | `open_bp` |
| `.cnt` | Object contours in heliographic coordinates | `open_cnt` |

Fields are separated by variable amounts of whitespace, except for BP column names, which are separated by `|`. In the layouts below, ellipses indicate repeated data and square brackets indicate optional fields. Line boundaries must be preserved in ABP and CNT files: each object occupies exactly two lines.

## DAT — Coronal Intensity

Annual files for the red line at **6374 Å** and the green line at **5303 Å** use naming patterns `r%Y*.dat` and `g*%Y.dat`. The year also occurs after a letter prefix (`r*%Y.dat`). `%Y` denotes a four-digit year.

```text
Corona wavelength
Kislovodsk YYYY
Jan T.U. 0 5 10 ... 350 355
DD HH MM I_0 I_5 I_10 ... I_350 I_355
...
Feb
DD HH MM I_0 I_5 I_10 ... I_350 I_355
...
```

| Element | Contents |
| --- | --- |
| First line | Wavelength in angstroms |
| Second line | Observation year |
| Line containing `T.U.` | Universal Time label and angular grid |
| Measurement line | Day of month, UT hours and minutes, followed by intensities |
| Month separator | `Feb`, `Mar`, `Apr`, `May`, `Jun`, `Jul`, `Aug`, `Sep`, `Oct`, `Nov`, `Dec` |

The standard grid contains **72 angles from 0° to 355° in 5° steps**, measured clockwise from the solar north pole. Each measurement line contains 75 fields. The header supplies the year and the current block supplies the month; January data begin immediately after the angular grid.

Intensities are integers. Missing values are marked with `-`, `x`, `X`, or `?` and are represented as `-1` when read. Dates without observations have no entries.

## ABP — Pixel Masks

```text
xc yc R P B0 L0 [auxiliary fields]
n_skip [auxiliary fields]
<n_skip additional lines>
N
<object parameters>
x1 y1 c1 x2 y2 c2 ... xM yM cM
...
```

### Header

| Field | Contents |
| --- | --- |
| `xc`, `yc` | Integer disk-center coordinates, in pixels |
| `R` | Integer disk radius, in pixels |
| `P` | Disk orientation angle, in degrees |
| `B0`, `L0` | Heliographic latitude and longitude of the disk center, in degrees |
| `n_skip` | Number of additional lines preceding the object-count line |
| `N` | Number of objects |

When `n_skip = 0`, the `N` line immediately follows the second header line.

### Object Block

The first line contains integer parameters:

| Position | Contents |
| --- | --- |
| 1 | Object number within the file |
| 2 | Mask area in pixels (`area_px`) |
| 3 | Group number |
| 4–5 | Auxiliary fields |
| 6 | Object identifier component |
| 7 | Additional identifier component; for sunspots, also an umbra flag: `0` means absent, a nonzero value means present |

The second line lists **triplets `x y c`**: pixel coordinates followed by an additional integer code. The mask lists the object's pixels rather than tracing its boundary.

The number of triplets equals `area_px`. A file containing `N` objects has `3 + n_skip + 2N` lines.

## BP — Object Parameters

```text
<observation information>
<geometric parameters>
column_1 | column_2 | ... |
<object parameter values>
...
Total ...
```

The descriptive header includes the original path, date and time, processing parameters (`parameters:`), and observer (`Observer:`). Geometric parameters use the following labels:

| Label | Contents |
| --- | --- |
| `R`, `xc`, `yc` | Disk radius and center coordinates, in pixels |
| `P` | Disk orientation angle, in degrees |
| `D` | Disk-center latitude (`B0`), in degrees |
| `L0` | Disk-center longitude, in degrees |
| `kol` | Number of objects |

The table columns depend on the object type. Filament tables use the following columns:

| Columns | Contents |
| --- | --- |
| `qmx`, `fimx` | Latitude and longitude of the first characteristic point, in degrees |
| `qmn`, `fimn` | Latitude and longitude of the second characteristic point, in degrees |
| `Int` | Intensity indicator |
| `S` | Object area |

The `um` label denotes a sunspot umbra.

The footer begins with `Total` and contains summary quantities. Text fields and totals allow a comma as the decimal separator.

## CNT — Heliographic Contours

```text
<field 1> <field 2> <field 3> P B0 L0 [auxiliary fields]
<auxiliary line>
<contour description>
B1 L1 B2 L2 ... BK LK
...
```

Fields 4–6 of the first line contain `P`, `B0`, and `L0`, in degrees.

After the first two lines, each contour occupies two lines: its description and its coordinates. **Coordinates are stored as latitude `B` followed by longitude `L`**, in degrees. Fractional values use a decimal point. The number of coordinate values is even, and their order defines the traversal of the contour.

A file containing `N` contours has `2 + 2N` lines.