Just to make things 100% clear, I am not trying to turn this into a sidereal vs tropical debate, I am just asking Bob/ua to clearify if I have the correct understanding of his techniques.
The birth chart need not be Sidereal nor planetary positions precessed for use in later in life events as most of the planets will not precess much in an entire lifetime.
Accept my 4 decades of experience or follow the instructions and test the technique for 40 years yourself.
I have found precession corrected solar and lunar returns produce the most appropriate combination of progressed lunar return angles and planetary and/or midpoint positions to them to describe an event. Work is presented in the Tropical zodiac as most who read charts use it. Signs are of no importance to me as I am seeking aspects to angles which are measured in DMS by planets measured in the same manner. To get them signs need not be used. Further, longitudinal positions are not the true positions of bodies in space.
I only use what exists in nature in the construction of charts - the positions of points in space for chart angles, planetary and midpoint positions and major astrological aspects between them, all measured in right ascension. Signs and houses are constructs by man, not nature. Measuring in right ascension avoids using them. As stated above work is presented in the Tropical zodiac for the convenience of most who look at the charts. Personally, I do not care which zodiac signs are represented. I do not use signs nor houses in my work but on rare occasions note a congruence I have noted in a progressed lunar chart for an event.
Event June 12, 1950, 7:27 AM, Fullerton, CA.
Locate the chart for which the progressed lunar is sought to the site of the event.
Eden was born in Long Beach, CA. The event was in Fullerton, CA. Relocate the natal.
Margaret Eden - Natal Relocated; Apr 17 1926, 10:20 AM, PST; Fullerton CA 33°N52'13'' 117°W55'28''
Do the nearest preceding PRECESSED solar return or demi-solar return for the location of the event.
Birth date - April 17th, event date - June 12th. Do a regular precession corrected solar return.
Margaret Eden - Solar Return; precession corrected; Apr 17 1950, 2:04:33 PM, PST; Fullerton CA 33°N52'13'' 117°W55'28''
Using the solar return Moon do the nearest PRECESSED lunar or demi-lunar before the date and time of the event for the location of the event.
Margaret Eden - Lunar Return; precession corrected; Jun 11 1950, 3:18:34 AM, PDT; Fullerton CA 33°N52'13'' 117°W55'28''
Get the transit Moon's position in right ascension from the event chart and subtract the lunar return's Moon position in right ascension from it.
Transits Jun 12 1950, 7:27 AM, PDT, Fullerton, CA 33°N52'13'' 117°W55'28''; Moon 043°50'
Margaret Eden Lunar Return precession corrected; Jun 11 1950, 3:18:34 AM, PDT; Fullerton CA; Moon 030°24'
043°50' - 030°24' = 13°26'.
Add the difference to the right ascension of the lunar return MC.
13°26' + 295°55' = 309°21'. Lunar return MC at the time of the accident.
Find the lunar return planet with a position given that is nearest to this new MC's right ascension. it was Mercury rising.
Using the lunar return chart do a chart for Mercury rising. This gave a chart with 313°55' for the MC on my computer running Solar Fire.
Wanted is 309°21'. The Mercury rising charts MC must decrease by 4°34'.
Interpolation of sorts. The MC moves 1° for approximately every 4 minutes of time. This further reduces to 1' of arc for every 4 seconds of time.
To reduce the MC by 4 degrees subtract 16 minutes from the charts time (4 degrees at 4 minutes each) . To reduce by another 34 minutes of arc subtract 136 seconds (which is 2 minutes, 16 seconds of time - [136 seconds of arc at 4 seconds of time for each]) yielding a total of 18 minutes, 16 seconds of time to be subtracted from the Mercury rising chart time of 4:30:23 AM, PDT, leaving a time of 4:12:07 for the progressed lunar return.
Rename the Mercury rising chart to what it represents. I used Edens F 50 PLR (The F telling me the chart is in Fullerton the 50 telling me it is for 1950.
Put in 4:12:07 for the time of the chart and run it.
This yields the MC at the 309°20' needed with secondary progressed Moon on the Asc and secondary progressed Saturn on the Desc with return Pluto at 141°18' on the Nadir (142°43'). Nadir is 90 degrees in right ascension from the Asc (52°43' + 90° = 142°43').