This probably does not help, but what the heck...
AA COMMAND
Introduction
Anti-Aircraft Command controlled all AA guns (both heavy and light) and searchlights in the British Isles, it was a vital component of the Air Defence of Great Britain (ADGB).
AA Command was organised with other elements of ADGB, particularly in co-operation with RAF Fighter Command. For administrative purposes AA Command functioned under the War Office and as a result came within several Army commands, the geographical boundaries of its three AA corps in 1940 corresponded with the boundaries and areas of the six groups of RAF Fighter Command. Each AA corps therefore covered the same area as two groups of RAF Fighter Command.
A reorganisation in 1942 took place and the organisation of AA corps and divisions was replaced by an entirely new framework based on AA groups. This allowed a far greater conformity with the existing layout of RAF Fighter Command's structure.
Although AA Command was a separate tactical Army unit – responsible for AA gun and searchlight defence of the British Isles, and commanded by a General – for operations it came under the control of RAF Fighter Command.
Organisation 1939 – 1943
On 1 April 1939 the AA Corps was raised in status to AA Command, a headquarters was established at 'Glenthorn ', a house in the grounds of RAF Fighter Command HQ at Stanmore. Initially under the command of Lieutenant-General Alan Brooke, his replacement, Lieutenant-General Sir Frederick Pile Bt, was appointed C-in-C 16 weeks later, retaining this position until the end of the war.
At the outbreak of WWII AA Command was organised into seven geographically based divisions. Each division was responsible for a number of brigades, which commanded a number of regiments. By the end of 1939 seven divisions were in place:
▪ 1 AA Division formed 15 Dec 1935 at Uxbridge
▪ 2 AA Division formed 01 Sept 1936 at RAF Hucknall
▪ 3 AA Division formed 01 Sept 1938 at Edinburgh
▪ 4 AA Division formed 01 Sept 1938 at Chester
▪ 5 AA Division formed 01 Sept 1938 at Reading
▪ 6 AA Division formed 21 Sept 1939 at Uxbridge
▪ 7 AA Division formed 16 July1939 at Newcastle.
Five more were added the following year:
▪ 8 AA Division formed 16 Oct 1940 at Bristol
▪ 9 AA Division formed 16 Oct 1940 at Cardiff
▪ 10 AA Division formed 11 Nov 1940 at York
▪ 11 AA Division formed 11 Nov 1940 at Birmingham
▪ 12 AA Division formed 15 Nov 1940 at Glasgow.
On 11 November 1940 an extra level of command was added between AA Command and its divisions:
▪ 1 AA Corps controlled: 1, 5, 6, 8, and 9AA Divisions
▪ 2 AA Corps controlled: 2, 4, 10, and 11AA Divisions
▪ 3 AA Corps controlled 3 AA Corps, plus 7, and 12AA Divisions.
In order to achieve the greatest operational efficiency, the command was reorganised on 30 September 1942, when all 12 divisions were disbanded and replaced by six groups, which now formed the only level between AA Command HQ and brigades. The six group headquarters were now located at the corresponding six RAF Group operations rooms.
AA Brigade
An AA Brigade was the lowest of the territorially organised functions of AA Command. After 1942 an AA Brigade was responsible to its respective Group HQ.
AA Regiment, Batteries and Troops
Regiments were the highest level in the command structure without permanent territory and controlled the batteries. A regiment and its batteries were able to move between fixed gun sites, or relocate mobile guns or searchlights from one position to the other.
A regiment was divided into three or four batteries which manned the guns, but for deployment around several defensive sites under the control of the same battery; they were sub-divided into a number of AA Troops. The primary role of the troops was AA defence; each gun and searchlight site was regarded as a defended island into which enemy ground forces would not be able to penetrate. Troops belonging to a battery were given a letter prefix to identify them.
AA Command had two main research stations devoted entirely to its problems and employing some hundreds of scientists. The Operations Research Group consists of about 70 scientists and statisticians who work in a three-storied suburban vicarage and overflow into two small army huts" - p.12, 'Roof Over Britain - The Official Story of the A.A. Defences, 1939-1942', HMSO, 1943