Problem
A Celestial Sight Reduction includes Altitude (Hc), Azimuth (Zn), Intercept, and whether Toward or Away. Altitude and Azimuth is shown on the Find Celestial Body Form. Intercept and Toward/Away is not shown.

Workaround
For a workaround, the navigator views the Line of Position which Celestial Navigation plugin draws on the Open CPN chart, and then uses the measurement tool to measure the distance from the DR/Fix to the LOP. That's the intercept. For Towards / Away, the navigator notes if the LOP is between the DR/Fix position and the Observed Body (that's towards), or if the LOP is behind the DR/Fix and the Observed Body ( that's away).

Recommendation
It would be much better to output the Intercept and Away/Toward on the Find Celestial Body form right next to the Altitude and Azimuth. Intercept calculation is simple. It is Hc (Altitude) minus Ho (Altitude Observed). Since the plug in stores Hc and Ho in decimal degrees, a = Hc-Ho will also be decimal degrees. Intercept is traditionally displayed in arc-minutes. To do that, multiply decimal degrees by 60. It is well known that 1 arc-minute is 1 nautical mile. So, no further unit of measure conversion is necessary.

Away and Towards is also simple to derive. If Hc > Ho then "Away". Else "Toward".

The attachment describes additional information.

Display Celestial Sight Reduction Intercept and Toward:Away on the Find Celestial Body Form PDF.pdf